U.S. patent application number 10/370605 was filed with the patent office on 2003-08-28 for three-dimensional optical waveguide, method of manufacturing same, optical module, and optical transmission system.
Invention is credited to Ishida, Kaoru, Korenaga, Tsuguhiro.
Application Number | 20030161573 10/370605 |
Document ID | / |
Family ID | 27678567 |
Filed Date | 2003-08-28 |
United States Patent
Application |
20030161573 |
Kind Code |
A1 |
Ishida, Kaoru ; et
al. |
August 28, 2003 |
Three-dimensional optical waveguide, method of manufacturing same,
optical module, and optical transmission system
Abstract
A three-dimensional optical waveguide is formed by laminating
planar substrates such as a plurality of lens substrates and, an
isolator substrate and a wavelength division multiplexing filter,
the optical substrates at least include a waveguide substrate
having a waveguide and a reflecting surface. In the
three-dimensional optical waveguide, the planar substrates are
positioned by markers integrally formed on at least two of the
planar substrates. Light directed into the waveguide is reflected
by a reflecting surface and passes through the lens substrates and
the isolator substrate.
Inventors: |
Ishida, Kaoru; (Osaka,
JP) ; Korenaga, Tsuguhiro; (Osaka, JP) |
Correspondence
Address: |
SMITH, GAMBRELL & RUSSELL, LLP
1850 M STREET, N.W., SUITE 800
WASHINGTON
DC
20036
US
|
Family ID: |
27678567 |
Appl. No.: |
10/370605 |
Filed: |
February 24, 2003 |
Current U.S.
Class: |
385/14 |
Current CPC
Class: |
G02B 6/12002 20130101;
G02B 6/4204 20130101; G02B 6/4214 20130101; Y10S 385/901 20130101;
G02B 6/43 20130101 |
Class at
Publication: |
385/14 |
International
Class: |
G02B 006/12 |
Foreign Application Data
Date |
Code |
Application Number |
Feb 28, 2002 |
JP |
2002-054375 |
Claims
What is claimed is:
1. A three-dimensional optical waveguide comprising a lamination of
at least a planar substrate having a planar optical waveguide and a
planar substrate having a sheet optical element.
2. A three-dimensional optical waveguide according to claim 1,
wherein the planar substrate having a sheet optical element is one
of a lens layer, an isolator layer and a filter layer.
3. A three-dimensional optical waveguide according to claim 2,
wherein the planar substrate having the planar waveguide, and the
said one of the lens layer, the isolator layer and the filter layer
are integrally formed on forming glass.
4. A three-dimensional optical waveguide according to claim 2 or
claim 3, wherein a reflecting surface is formed on the planar
optical waveguide and light passes through the said one of the lens
layer, the isolator layer and the filter layer.
5. A three-dimensional optical waveguide according to claim 4,
further comprising at least one of a light receiving element and a
light emitting element.
6. A three-dimensional optical waveguide according to claims 1,
wherein the planar substrates are positioned with respect to each
other by markers integrally formed on at least two planar
substrates.
7. A method of manufacturing a three-dimensional optical waveguide
comprising: providing a plurality of planar substrates, each having
a planar optical waveguide; forming a marker on each of the planar
substrates at a same time; and laminating the planar substrates by
positioning the planar substrates by using the markers.
8. A method of manufacturing a three-dimensional optical waveguide
according to claim 7, wherein the markers have one of a concave or
convex shape, and wherein before the planar substrates are
laminated, the planar substrates are positioned by applying light
to the markers and causing the light to be reflected or transmitted
by the markers.
9. A method of manufacturing a three-dimensional optical waveguide
according to claim 8, wherein bottom surfaces of the markers are
one of inclined surfaces, scattering surfaces and lens
surfaces.
10. An optical transmitter module, comprising: an electric input
terminal; a light emitting element connected to the electric input
terminal; the three-dimensional optical waveguide according to
claim 3, the waveguide transmitting light emitted from the light
emitting element; and an optical output terminal outputting light
transmitted through the three-dimensional optical waveguide.
11. An optical receiver module, comprising: an optical input
terminal; the three-dimensional optical waveguide according to
claim 3 connected to the optical input terminal; a light receiving
element, that receives light transmitted through the
three-dimensional optical waveguide; and an electric output
terminal connected to the light receiving element.
12. An optical transmitter and receiver module, comprising: an
electric input terminal; a three-dimensional optical waveguide
including a lamination of at least a planar substrate having a
planar optical waveguide, a planar substrate having an isolator,
and a planar substrate having a wavelength division multiplexing
filter; a light emitting element connected to the electric input
terminal and connected to the three-dimensional optical waveguide;
a light receiving element connected to the three-dimensional
optical waveguide; an electric output terminal connected to the
light receiving element; and an optical input and output terminal
connected to the three-dimensional optical waveguide, wherein an
electric signal input from the electric input terminal is converted
into an optical signal and transmitted from the optical input and
output terminal, and an optical signal received by the optical
input and output terminal is converted into an electric signal and
output to the electric output terminal.
13. An optical transmission system for transmission and reception,
comprising: an optical transmitter module, including: an electric
input terminal; a light emitting element connected to the electric
input terminal; a three-dimensional optical waveguide having: a
lamination of at least a planar substrate having a planar optical
waveguide connected to the light emitting element and a planar
substrate having a sheet optical element; the waveguide is
transmitting light emitted from the light emitting element; and an
optical output terminal outputting light transmitted through the
three-dimensional optical waveguide; an optical fiber cable
connected to the optical transmitter module; and an optical
receiver module, including: an optical input terminal; a
three-dimensional optical waveguide having: a lamination of at
least a planar substrate having a planar optical waveguide
connected to the optical input terminal and a planar substrate
having a sheet optical element; a light receiving element, that
receives light transmitted through the three-dimensional optical
waveguide; and an electric output terminal connected to the light
receiving element; the optical receiver module is connected to the
optical fiber cable.
14. An optical transmission system for optical transmission and
reception, comprising: the optical transmitter and receiver module
according to claim 12; and an optical fiber cable connected to the
optical transmitter and receiver module.
Description
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to a three-dimensional optical
waveguide, a method of manufacturing the same, an optical module,
and an optical transmission system for enhancing the performance of
an optical device.
[0003] 2. Related Art of the Invention
[0004] Conventionally, when a three-dimensional optical waveguide
is formed, for example, in order that light traveling through a
waveguide is output vertically with respect to the waveguide, as
shown in FIG. 26, a planar filter 1006 such as a wavelength
division multiplexing (WDM) filter is inserted in a groove 1002
obliquely formed in a planar waveguide 1001, and the light
reflected or transmitted by the planar filter 1006 is oriented with
respect to a light receiving element 1008, a lens system and
another planar optical waveguide which are disposed spatially,
thereby forming the three-dimensional optical waveguide.
[0005] However, in such a three-dimensional optical waveguide,
spatial adjustment in each waveguide and the lens system is
extremely difficult. For example, when a planar wavelength division
multiplexing filter is inserted in a planar optical waveguide, it
is necessary that the formation of the groove for supporting the
wavelength division multiplexing filter be performed extremely
precisely. In addition, after the insertion of the wavelength
division multiplexing filter into the groove, a precise adjustment
for fine positioning of the wavelength division multiplexing filter
is further required.
[0006] Therefore, when it is intended to enhance the performance by
inserting an optical device such as an isolator in such a
three-dimensional optical waveguide, since the number of parts
requiring adjustment increases, the cost increases.
SUMMARY OF THE INVENTION
[0007] In view of the above-mentioned problem, an object of the
present invention is to provide a three-dimensional optical
waveguide, a method of manufacturing the same, an optical module
and an optical transmission system that are low in cost and do not
require complicated adjustment.
[0008] The 1st aspect of the present invention is a
three-dimensional optical waveguide comprising a lamination of at
least a planar substrate (1, 31, 51, 61, 71, 91, 301, 711, 1311,
1321, 1331) having a planar optical waveguide (2, 12, 22, 32, 52,
62, 72, 92, 702, 712, 902, 1322, 1332, 1342, 1352, 1362) and a
planar substrate (3, 8, 10, 30, 33, 43, 53, 63, 70, 73, 76, 93, 98,
300, 900, 1308, 1330, 1340, 1343, 1350) having a sheet optical
element (4, 5, 6, 7, 9, 24, 34, 29, 44, 54, 64, 74, 79, 94, 95, 96,
97, 209, 304, 404, 704, 904, 906, 909, 914, 919, 1304, 1305, 1306,
1307, 1316, 1324, 1334, 1344, 1354, 1364).
[0009] The 2nd aspect of the present invention is a
three-dimensional optical waveguide according to the 1st aspect,
wherein the planar substrate having a sheet optical element is one
of a lens layer, an isolator layer and a filter layer.
[0010] The 3rd aspect of the present invention is a
three-dimensional optical waveguide according to the 2nd aspect,
wherein the planar substrate having the planar waveguide, and the
said one of the lens layer, the isolator layer and the filter layer
are integrally formed on forming glass.
[0011] The 4th aspect of the present invention is a
three-dimensional optical waveguide according to the 2nd aspect or
3rd aspect, wherein a reflecting surface is formed on the planar
optical waveguide and light passes through the said one of the lens
layer, the isolator layer and the filter layer.
[0012] The 5th aspect of the present invention is a
three-dimensional optical waveguide according to the 4th aspect,
further comprising at least one of a light receiving element and a
light emitting element.
[0013] The 6th aspect of the present invention is a
three-dimensional optical waveguide according to the 1st aspect,
wherein the planar substrates are positioned with respect to each
other by markers integrally formed on at least two planar
substrates.
[0014] The 7th aspect of the present invention is a method of
manufacturing a three-dimensional optical waveguide comprising:
[0015] providing a plurality of planar substrates (3, 8, 10, 30,
33, 43, 53, 63, 70, 73, 76, 93, 98, 300, 900, 1308, 1330, 1340,
1343, 1350), each having a planar optical waveguide;
[0016] forming a marker (101, 103) on each of the planar substrates
(3, 8, 10, 30, 33, 43, 53, 63, 70, 73, 76, 93, 98, 300, 900, 1308,
1330, 1340, 1343, 1350) at a same time; and
[0017] laminating the planar substrates (3, 8, 10, 30, 33, 43, 53,
63, 70, 73, 76, 93, 98, 300, 900, 1308, 1330, 1340, 1343, 1350) by
positioning the planar substrates by using the markers (101,
103).
[0018] The 8th aspect of the present invention is a method of
manufacturing a three-dimensional optical waveguide according to
the 7th aspect, wherein the markers have one of a concave or convex
shape, and wherein before the planar substrates are laminated, the
planar substrates are positioned by applying light to the markers
and causing the light to be reflected or transmitted by the
markers.
[0019] The 9th aspect of the present invention is a method of
manufacturing a three-dimensional optical waveguide according to
the 8th aspect, wherein bottom surfaces of the markers are one of
inclined surfaces, scattering surfaces and lens surfaces.
[0020] The 10th aspect of the present invention is an optical
transmitter module, comprising:
[0021] an electric input terminal (1105);
[0022] a light emitting element (69, 89, 999, 1209, 1219, 1229,
1239, 1249) connected to the electric input terminal (1105);
[0023] the three-dimensional optical waveguide according to the 3rd
aspect, the waveguide transmitting light emitted from the light
emitting element (69, 89, 999, 1209, 1219, 1229, 1239, 1249);
and
[0024] an optical output terminal (1107) outputting light
transmitted through the three-dimensional optical waveguide.
[0025] The 11th aspect of the present invention is an optical
receiver module, comprising:
[0026] an optical input terminal (1117);
[0027] the three-dimensional optical waveguide according to the 3rd
aspect connected to the optical input terminal (1117);
[0028] a light receiving element, that receives light (59, 99,
1109, 1119, 1129, 1139, 1149) transmitted through the
three-dimensional optical waveguide; and
[0029] an electric output terminal (1115) connected to the light
receiving element.
[0030] The 12th aspect of the present invention is an optical
transmitter and receiver module, comprising:
[0031] an electric input terminal (1105);
[0032] a three-dimensional optical waveguide including a lamination
of at least a planar substrate (3, 8, 10, 30, 33, 43, 53, 63, 70,
73, 76, 93, 98, 300, 900, 1308, 1330, 1340, 1343, 1350) having a
planar optical waveguide (2, 12, 22, 32, 52, 62, 72, 92, 702, 712,
902, 1322, 1332, 1342, 1352, 1362), a planar substrate (3, 8, 10,
30, 33, 43, 53, 63, 70, 73, 76, 93, 98, 300, 900, 1308, 1330, 1340,
1343, 1350) having an isolator (8, 98, 1108, 1118, 1128, 1308), and
a planar substrate (3, 8, 10, 30, 33, 43, 53, 63, 70, 73, 76, 93,
98, 300, 900, 1308, 1330, 1340, 1343, 1350) having a wavelength
division multiplexing filter;
[0033] a light emitting element (69, 89, 999, 1209, 1219, 1229,
1239, 1249) connected to the electric input terminal (1105) and
connected to the three-dimensional optical waveguide;
[0034] a light receiving element (69, 89, 999, 1209, 1219, 1229,
1239, 1249) connected to the three-dimensional optical
waveguide;
[0035] an electric output terminal (1115) connected to the light
receiving element (69, 89, 999, 1209, 1219, 1229, 1239, 1249);
and
[0036] an optical input and output terminal (1115) connected to the
three-dimensional optical waveguide,
[0037] wherein an electric signal input from the electric input
terminal (1105) is converted into an optical signal and transmitted
from the optical input and output terminal (1115), and an optical
signal received by the optical input and output terminal (1115) is
converted into an electric signal and output to the electric output
terminal.
[0038] The 13th aspect of the present invention is an optical
transmission system for transmission and reception, comprising:
[0039] an optical transmitter module, including:
[0040] an electric input terminal;
[0041] a light emitting element connected to the electric input
terminal;
[0042] a three-dimensional optical waveguide having:
[0043] a lamination of at least a planar substrate having a planar
optical waveguide connected to the light emitting element and a
planar substrate having a sheet optical element;
[0044] the waveguide is transmitting light emitted from the light
emitting element; and
[0045] an optical output terminal outputting light transmitted
through the three-dimensional optical waveguide;
[0046] an optical fiber cable connected to the optical transmitter
module; and
[0047] an optical receiver module, including:
[0048] an optical input terminal;
[0049] a three-dimensional optical waveguide having:
[0050] a lamination of at least a planar substrate having a planar
optical waveguide connected to the optical input terminal and a
planar substrate having a sheet optical element;
[0051] a light receiving element, that receives light transmitted
through the three-dimensional optical waveguide; and
[0052] an electric output terminal connected to the light receiving
element;
[0053] the optical receiver module is connected to the optical
fiber cable.
[0054] The 14th aspect of the present invention is an optical
transmission system for optical transmission and reception,
comprising:
[0055] the optical transmitter and receiver module according to
12th aspect; and
[0056] an optical fiber cable connected to the optical transmitter
and receiver module.
BRIEF DESCRIPTION OF THE DRAWINGS
[0057] FIG. 1 is a cross-sectional view showing the structure of a
three-dimensional optical waveguide according to a first embodiment
of the present invention.
[0058] FIG. 2 is a cross-sectional view showing the structure of a
three-dimensional optical waveguide according to a modification of
the first embodiment of the present invention.
[0059] FIG. 3 is a cross-sectional view showing the structure of a
three-dimensional optical waveguide according to a second
embodiment of the present invention.
[0060] FIG. 4 is a cross-sectional view showing the structure of a
three-dimensional optical waveguide according to a modification of
the second embodiment of the present invention.
[0061] FIG. 5 is a cross-sectional view showing the structure of a
three-dimensional optical waveguide according to a third embodiment
of the present invention.
[0062] FIG. 6 is a cross-sectional view showing the structure of a
three-dimensional optical waveguide according to a modification of
the third embodiment of the present invention.
[0063] FIG. 7 is a cross-sectional view showing the structure of a
three-dimensional optical waveguide according to a fourth
embodiment of the present invention.
[0064] FIG. 8 is a cross-sectional view showing the structure of a
three-dimensional optical waveguide according to a modification of
the fourth embodiment of the present invention.
[0065] FIG. 9 is a cross-sectional view showing the structure of a
three-dimensional optical waveguide according to a fifth embodiment
of the present invention.
[0066] FIG. 10 is a cross-sectional view showing the structure of a
three-dimensional optical waveguide according to a sixth embodiment
of the present invention.
[0067] FIGS. 11(a) to 11(f) are cross-sectional views showing a
marker formed in each substrate and used when the three-dimensional
optical waveguide of the present invention is manufactured.
[0068] FIGS. 12(a) to 12(c) are schematic views showing a method of
manufacturing the three-dimensional optical waveguide of the
present invention.
[0069] FIGS. 13(a) to 13(c) are schematic views showing a modified
method of manufacturing the three-dimensional optical waveguide of
the present invention.
[0070] FIGS. 14(a) and 14(b) are schematic views showing a further
method of manufacturing the three-dimensional optical waveguide of
the present invention.
[0071] FIGS. 15(a) and 15(b) are schematic views showing a still
further method of manufacturing the three-dimensional optical
waveguide of the present invention.
[0072] FIGS. 16(a) and 16(b) are schematic views showing yet
another method of manufacturing the three-dimensional optical
waveguide of the present invention.
[0073] FIGS. 17(a) to 17(d) are schematic views showing still
another method of manufacturing the three-dimensional optical
waveguide of the present invention.
[0074] FIGS. 18(a) and 18(b) are schematic views showing a still
further method of manufacturing the three-dimensional optical
waveguide of the present invention.
[0075] FIG. 19 is a schematic view showing the structure of an
optical transmitter module of the present invention.
[0076] FIG. 20 is a schematic view showing the structure of an
optical transmitter module of the present invention.
[0077] FIG. 21 is a schematic view showing the structure of an
optical receiver module of the present invention.
[0078] FIG. 22 is a schematic view showing the structure of an
optical receiver module of the present invention.
[0079] FIG. 23 is a schematic view showing the structure of an
optical transmitter and receiver module of the present
invention.
[0080] FIG. 24 is a schematic view showing the structure of an
application of the optical transmitter and receiver module of the
present invention.
[0081] FIG. 25 is a perspective view showing a concrete example of
an optical input terminal, an optical output terminal or an optical
input and output terminal of the present invention.
[0082] FIG. 26 shows the structure of the waveguide according to
the prior art.
[0083] Explanation of Reference Numerals
[0084] 1, 11 Waveguide substrate
[0085] 2, 12 Waveguide
[0086] 3, 10 Lens substrate
[0087] 4, 9 Lens
[0088] 8 Isolator substrate
[0089] 13, 14 Reflecting surface
[0090] 59, 99 Surface emitting laser
[0091] 69, 89 Surface-mount photodiode
[0092] 101, 103 Marker
[0093] 102, 104 Bottom surface
[0094] 105 Light source
[0095] 106 Light receiver
[0096] 107, 108 Image
[0097] Embodiments of the Invention
[0098] (First Embodiment)
[0099] FIG. 1 shows the cross-sectional structure of a
three-dimensional optical waveguide according to a first embodiment
of the present invention.
[0100] A waveguide substrate 1 as the planar substrate having a
planar waveguide of the present invention is formed of forming
glass, and a waveguide 2 which is the planar optical waveguide of
the present invention is formed on the top surface of the waveguide
substrate 1. At an end of the waveguide 2, a reflecting surface 13
which is the reflecting surface of the present invention comprising
a mirror or the like is formed. On the top surface of the waveguide
substrate 1, a lens substrate 3 which is the planar substrate
having a lens layer of the present invention is laminated. In the
lens substrate 3, a lens 4 is integrally formed of forming glass
(the same for the lens substrate described below).
[0101] Above the lens substrate 3, a polarizer 5, a Faraday rotator
6 and a polarizer 7 are laminated in this order. These elements
constitute an isolator substrate 8 which is the planar substrate
having an isolator of the present invention. On the top surface of
the isolator substrate 8, a lens substrate 10 is laminated which is
the planar substrate having a lens layer of the present invention.
In the lens substrate 10, a lens 9 is integrally formed of forming
glass. Above the lens layer 10, a waveguide substrate 11 which is
the planar optical waveguide of the present invention is laminated.
The waveguide substrate 11 is also formed of forming glass.
[0102] In a lower part of the waveguide substrate 11, a waveguide
12 which is the planar optical waveguide of the present invention
is formed. At an end of the waveguide 12, a reflecting surface 14
which is the reflecting surface of the present invention comprising
a mirror or the like is formed. The reflecting surface 13, the lens
4, the lens 9 and the reflecting surface 14 are disposed so that
the horizontal positions thereof are aligned in the vertical
direction. The method of position alignment will be described
later. The reflecting surface 13 is angled (inclined by 45.degree.)
so that light traveling along the horizontal direction is made to
travel in the vertical direction. The reflecting surface 14 is
angled (inclined by 45.degree.) so that light traveling along the
vertical direction is made to travel in the horizontal direction).
The substrates are bonded by an ultraviolet cure adhesive or the
like.
[0103] In this description, it is assumed that the vertical
direction and the horizontal (longitudinal) direction coincide with
the vertical direction and the horizontal (longitudinal) direction
of FIG. 1 (this applies to the description that follows).
[0104] When such a three-dimensional optical waveguide is
manufactured, as described above, precise position alignment is
necessary between the waveguide substrate 1 having the reflecting
surface 13 and the lens substrate 3 having the lens 4, between the
lens substrate 3 and the lens substrate 10 having the lens 9 and
between the lens substrate 10 and the optical waveguide substrate
11 having the reflecting surface 14. FIGS. 11 to 12 are views for
assistance in explaining the method of such position alignment.
[0105] First, a concave marker 101 as shown in FIG. 11(a) is formed
integrally with the substrates (the waveguide substrate 1, the lens
substrate 3, the lens substrate 10, and the waveguide substrate 11)
by pressing the forming glass. As shown in FIG. 11(a), the marker
101 has a bottom surface 102 angled at 45.degree..
[0106] Next, with reference to FIGS. 12(a) to 12(c), the process of
aligning the substrates will be described with the waveguide
substrate 1 and the lens substrate 3 as an example.
[0107] The bottom surfaces 102 angled as described above are formed
in the same direction with respect to the direction of length of
the substrates. The horizontal positions of the markers 101 formed
on the substrates are determined so that predetermined spacings are
provided in the direction of length of the substrates (hereinafter,
referred to as the X direction), in the direction orthogonal to the
X direction within the planes of the substrates (hereinafter,
referred to as the Y direction) and in the direction in which the
substrates are laminated (the vertical direction, that is, the
direction orthogonal to the X and the Y directions, hereinafter,
referred to as the Z direction). For example, the substrates are
laminated so that, as shown in FIGS. 12(a) to 12(c), the position
of the marker 101 formed in the waveguide substrate 1 and the
position of the marker 101 formed in the lens substrate 3 are the
same in the Y direction of the substrates, a predetermined spacing
a is provided in the X direction and a predetermined spacing c is
provided in the Z direction.
[0108] As shown in FIG. 12(a), the waveguide substrate 1 is
disposed below, and the lens substrate 3 is disposed above the
waveguide substrate 1 through an ultraviolet cure adhesive. Then, a
light source 105 emitting parallel light is disposed below the
waveguide substrate 1, and a light receiver 106 such as a CCD
camera is disposed above the lens substrate 3 and at a side of the
laminated substrates. When parallel light is emitted from the light
source 105, part of the emitted parallel light is reflected by the
bottom surfaces 102 in parts where the markers 101 are present, and
the reflected part of the light reaches the light receiver 106
disposed at a side of the laminated substrates. At the parts where
the markers 101 are absent, the emitted parallel light is all
transmitted, and the transmitted light reaches the light receiver
106 disposed above the lens substrate 3.
[0109] FIG. 12(b) shows images obtained from the light receiver 106
disposed above the lens substrate 3 in this manner. Here, an image
108 corresponds to the marker 101 formed in the waveguide 1, and an
image 107 corresponds to the marker 101 formed in the lens
substrate 3. These images are shown on the light receiver 106 as
parts darker than any peripheral part. Then, adjustment is made by
moving the waveguide substrate 1 and the lens substrate 3 in the
horizontal direction so that the positions of the images 107 and
108 in the Y direction coincide with each other and the spacing
between the images 107 and 108 in the X direction is the
predetermined spacing a.
[0110] FIG. 12(c) shows images obtained from the light receiver 106
disposed at a side of the laminated substrates as described above.
Here, an image 116 corresponds to the marker 101 formed in the lens
substrate 3, and an image 117 corresponds to the marker 101 formed
in the waveguide substrate 1. These images are shown on the light
receiver 106 as parts brighter than any peripheral part. Then,
adjustment is made by moving the waveguide 1 and the lens substrate
3 in the Z direction so that the spacing between the image 116 and
the image 117 is the predetermined spacing c. When the elements are
brought into predetermined position alignment, ultraviolet light is
applied to the waveguide substrate 1 and the lens substrate 3 to
cure the ultraviolet-cure adhesive filling the space between the
waveguide substrate 1 and the lens substrate 3, thereby bonding the
substrates 1 and 3.
[0111] Likewise, position alignment is made between the lens
substrate 3 and the lens substrate 10 and between the lens
substrate 10 and the waveguide substrate 11. At this time, the
position alignment between the lens substrate 3 and the lens
substrate 10 is performed by an operation similar to the
above-described one with the isolator substrate 8 sandwiched
between the lens substrate 3 and the lens substrate 10.
[0112] At this time, while the predetermined spacing a may be
different among the substrates, it is determined so that the
horizontal positions of the reflecting surface 13, the lens 4, the
lens 9 and the reflecting surface 9 are aligned in the vertical
direction when the substrates are laminated.
[0113] Next, the operation performed when such a three-dimensional
optical waveguide is used will be described.
[0114] The light directed into the waveguide substrate 1 travels
through the waveguide 2, and is reflected upward by the reflecting
surface 13 to be incident on the lens 4. The light having exited
from the lens 4 passes through the isolator substrate 8 and the
lens 9, is horizontally reflected by the reflecting surface 4, and
travels through the waveguide 12.
[0115] By doing this, a low-cost and precise three-dimensional
optical waveguide not requiring a complicated adjustment is
provided.
[0116] While in the description given above, the substrates are
positioned so that the horizontal positions (in the X direction and
in the Y direction) of the markers 101 formed in the substrates are
the same in the Y direction and the predetermined spacing a is
provided in the X direction, the substrates may be positioned so
that a predetermined spacing b is provided in the Y direction.
[0117] In the first embodiment, the lens substrate 10 is present
between the isolator substrate 8 and the waveguide substrate 11.
However, when the light reflected by the reflecting surface 13 can
be condensed on the reflecting surface 14 only by a lens 24 as
shown in FIG. 2, the lens substrate 10 is unnecessary. In that
case, similar effects to those described above are obtained.
[0118] While in the present embodiment, the light source 105 is
disposed below the waveguide substrate 1 when position alignment
between the waveguide substrate 1 and the lens substrate 3 is
performed, the light source 105 may be disposed at a side of the
waveguide substrate 1 and the lens substrate 3 as shown in FIG.
13(a). In that case, at the parts not coinciding with the bottom
surfaces 102 of the markers 101, the parallel light emitted from
the light source 105 is transmitted to the opposite side of the
waveguide substrate 1 and the lens substrate 3 as it is to reach
the light receiver 106 disposed at a side of the waveguide 1 and
the lens substrate 3, and at the parts coinciding with the bottom
surfaces 102 of the markers 101, part of the parallel light is
reflected upward to reach the light receiver 106 disposed above the
lens substrate 3.
[0119] Consequently, as the images obtained on the light receiver
106 disposed above the lens substrate 3, as shown in FIG. 13(b), an
image 109 corresponding to the marker 101 of the lens substrate 3
and an image 110 corresponding to the marker 101 of the waveguide
substrate 1 are shown on the light receiver 106 as parts brighter
than the peripheral part. As described above, when the light source
105 is disposed at a side of the waveguide substrate 1 and the lens
substrate 3, the waveguide substrate 1 and the lens substrate 3 can
be positioned in predetermined positions in the horizontal
direction by adjusting the spacing a between the image 109 and the
image 110 similar to the above-described case.
[0120] FIG. 13(c) shows images obtained from the light receiver 106
disposed at a side of the waveguide substrate 1 and the lens
substrate 3 as described above. Here, an image 118 corresponds to
the marker 101 formed in the lens substrate 3, and an image 119
corresponds to the marker 101 formed in the waveguide substrate 1.
These images are shown on the light receiver 106 as parts darker
than the peripheral part. Then, adjustment is made by moving the
waveguide 1 and the lens substrate 3 in the Z direction so that the
spacing between the image 118 and the image 119 is the
predetermined spacing c. When the elements are brought into
predetermined position alignment, the waveguide 1 and the lens
substrate 3 are bonded together similar to the above-described
case.
[0121] While the concave markers 101 are used for the positioning
of the substrates in the description given above, convex markers
103 may be used for the positioning. FIG. 11(d) shows a case where
the bottom surface 104 of the convex marker 103 is angled at
45.degree.. FIG. 11(e) shows a case where the bottom surface 104 of
the convex marker 103 has a scattering surface. FIG. 11(f) shows a
case where the bottom surface 104 of the convex marker 103 has a
lens configuration.
[0122] When these convex markers 103 are used, the horizontal
positions and the vertical positions of the substrates can be
adjusted similarly to the case of the concave markers 101 with the
spacing between each substrate being fixed by a spacer (not shown)
or filled with an adhesive as described above and with the light
source 105 being disposed below or at a side of the waveguide
1.
[0123] While in the description given above, the bottom surfaces of
the markers 101 and 103 are angled at 45.degree., they may be
angled at a different angle. In that case, by disposing the light
receiver 106 so that the light from the light source 105 is
projected onto the light receiver 106 upward or downward in a
slanting direction with respect to the substrates, the spacing
between each substrate can be similarly adjusted by observing the
images shown on the light receiver 106.
[0124] While in the description given above, the markers 101 and
103 of which bottom surfaces are inclined are used to perform the
positioning of the substrates in the horizontal direction and the
vertical direction, it is considered to use markers 101 having
bottom surfaces 102 of a different configuration.
[0125] FIGS. 14(a) and 15(a) show examples of arrangement of the
elements in a case where markers 101 of which bottom surfaces 102
have a lens configuration are used. As shown in FIG. 14(a), a light
source 111 is a diffusing light source, and is disposed below the
waveguide substrate 1 at a predetermined distance therefrom. The
light receiver 106 is disposed above the lens substrate 3. In the
waveguide substrate 1, a concave marker 101 having a bottom surface
102 of a lens configuration being concave when viewed from below is
disposed, and in the lens substrate 3, a concave marker 101 having
a bottom surface 102 of a lens configuration being convex when
viewed from below is disposed. Here, the concave lens of the bottom
surface 102 formed in the waveguide substrate 1 has a lens
configuration and a refractive index that refract into parallel
light the diffused light emitted from the light source 111 disposed
at the predetermined distance from the waveguide substrate 1.
[0126] The lens configuration as a convex lens and the refractive
index of the bottom surface 102 formed in the lens substrate 103
are a lens configuration and a refractive index that condense the
parallel light incident on the bottom surface 102 of the lens
substrate 3 on the light receiver 106 disposed above the lens
substrate 3. The positions of markers 101 of the substrates are the
same both in the X direction and in the Y direction, or are
predetermined positions. In this arrangement, when light is emitted
from the light source 111, the light passes through the marker 101
of the waveguide substrate 1 and the marker 101 of the lens
substrate 3 to be condensed on the light receiver 106. The images
obtained from the light receiver 106 at this time are shown in FIG.
14(b). That is, on the light receiver 106, an image 112 which is an
image of the marker 101 itself is formed and an image 113 condensed
by the bottom surface 102 having a lens configuration is formed
inside the image 112. As described above, by adjusting the
waveguide substrate 1 or the lens substrate 3 in the horizontal
direction so that the image 113 is formed inside the image 112,
positioning of the waveguide substrate 1 and the lens substrate 3
in the horizontal direction can be performed.
[0127] By adjusting the spacing between the waveguide substrate 1
and the lens substrate 3 so that the outside diameter of the image
113 on the light receiver 106 is a predetermined value (that is, so
that the light emitted from the light source 111 is most
excellently condensed on the light receiver 106), adjustment
(positioning in the vertical direction) of the spacing between the
waveguide substrate 1 and the lens substrate 3 can be made. While
in the FIG. 14(b), the two images 112 and 113 are situated side by
side, these are images formed when another markers 101 of the same
type are disposed so as to be situated side by side on the
substrates. The markers 101 may be disposed one by one on each of
the substrates as shown in FIG. 14(a).
[0128] FIG. 15(a) shows a modification of the structure of FIG.
14(a). In this case, the bottom surface 102 of the marker 101
formed in the waveguide substrate 1 has a lens configuration being
convex when viewed from below. The lens configurations as convex
lenses and the refractive indices of the bottom surface 102 formed
in the waveguide substrate 1 and the bottom surface 102 formed in
the lens substrate 3 are lens configurations and refractive indices
that condense the light emitted from the light source 111 on the
light receiver 106 disposed above the lens substrate 3 by way of
the bottom surface 102 of the waveguide substrate 1 and the bottom
surface 102 of the lens substrate 3. On the light receiver 106,
images 114 and 115 are similarly formed as shown in FIG. 15(b), and
the positioning of the waveguide substrate 1 and the lens substrate
3 in the horizontal and the vertical directions can be performed
similarly to the above-described case.
[0129] While FIGS. 14(a), 14(b), 15(a) and 15(b) are described with
reference to examples using the concave markers 101, the
above-described applies to cases where convex markers 101 are used
as shown in FIG. 11(f).
[0130] FIGS. 16(a) and 16(b) show a case in which the bottom
surfaces 102 of the markers 101 are scattering surfaces (see FIG.
11(b)). In this case, as shown in FIG. 16(a), the light receiver
106 and the light source 105 are disposed below the waveguide
substrate so as to adjoin each other. When parallel light is
emitted from the light source 105 in this arrangement, the light is
scattered at the scattering surfaces of the bottom surfaces 102 of
the markers 101, and part of the scattered light reaches the light
receiver 106 disposed below the waveguide substrate 1. FIG. 16(b)
shows images light-received on the light receiver 106. Here, an
image 120 corresponds to the marker 101 formed in the lens
substrate 3, and an image 121 corresponds to the marker 101 formed
in the waveguide substrate 1. By adjusting the distance between the
image 120 and the image 121 so as to be the predetermined spacing
a, positioning of the substrates in the horizontal direction can be
performed.
[0131] FIGS. 17(a) to 17(d) show a case where the bottom surfaces
102 of the markers 101 are inclined scattering surfaces. In this
case, as shown in FIG. 17(a), the light receiver 106 can be
disposed below the waveguide substrate 1, at a side of the
waveguide substrate 1 and the lens substrate 3 or above the lens
substrate. In this arrangement, the horizontal positions or the
vertical positions of the substrates can be adjusted by applying
light from the light source 105 disposed below the waveguide
substrate 1.
[0132] For example, by disposing the light receiver 106 above the
lens substrate 3 and at a side of the waveguide substrate 1 and the
lens substrate 3, positioning of the substrates in the horizontal
direction and positioning thereof in the vertical direction can be
performed at the same time like in the case shown in FIGS. 12(a) to
12(c). Moreover, by disposing the light receiver 106 below the
waveguide substrate 1 and at a side of the waveguide substrate 1
and the lens substrate 3, positioning of the substrates in the
horizontal direction and positioning thereof in the vertical
direction can also be performed at the same time. FIG. 17(b) shows
images shown on the light receiver 106 disposed above the lens
substrate 3. An image 122 corresponds to the marker 101 formed in
the lens substrate 3, and an image 123 corresponds to the marker
101 formed in the waveguide substrate 1. FIG. 17(c) shows images
shown on the light receiver 106 disposed at a side of the lens
substrate 3 and the waveguide substrate 1. An image 124 corresponds
to the marker 101 formed in the lens substrate 3, and an image 125
corresponds to the marker 101 formed in the waveguide substrate 1.
FIG. 17(d) shows images shown on the light receiver 106 disposed
below the waveguide substrate 1. An image 126 corresponds to the
marker 101 formed in the lens substrate 3, and an image 127
corresponds to the marker 101 formed in the waveguide substrate
1.
[0133] As described above, when the bottom surfaces of the markers
101 are inclined scattering surfaces, since the light receiver 106
can be disposed in three directions with respect to the substrates,
there is flexibility in the positioning method. For example,
positioning can be performed even when the laminated substrates do
not transmit light as described later. Positioning can be more
precisely performed by making the adjustment while observing the
light receivers 106 disposed in the three directions at the same
time.
[0134] Moreover, it is considered that the bottom surfaces 102 of
the markers 101 are inclined lens surfaces. In that case, as shown
in FIGS. 18(a) and 18(b), the light receiver 106 is disposed so as
to be shifted from the optical axis of the light source 105.
[0135] Moreover, it is considered that the bottom surfaces 102 of
the markers 101 are lens surfaces having scattering surfaces.
[0136] While in the description given above, the markers 101 formed
in the substrates are a combination of markers 101 of the same
kind, positioning may be performed with a combination of markers
101 of different kinds. For example, positioning may be performed
by forming in one substrate a marker 101 of which bottom surface
102 is inclined and forming in the other substrate a marker 101 of
which bottom surface 102 has a scattering surface. Moreover,
positioning may be performed by forming in one substrate a marker
101 of which bottom surface 102 is inclined and forming in the
other substrate a marker 101 of which bottom surface 102 has a lens
surface. Moreover, positioning may be performed by forming in one
substrate a marker 101 of which bottom surface 102 has a scanning
surface and forming in the other substrate a marker 101 of which
bottom surface 102 has a lens surface. When a marker 101 having a
lens surface is combined, the light emitted from the light source
105 is not necessarily strictly parallel.
[0137] While in the description given above, the method of
positioning of the substrates is described as a case where
positioning of the waveguide substrate 1 and the lens substrate 3
is performed, it is similarly applicable to a case where
positioning of other substrates (that is, the planar substrates of
the present invention) is performed.
[0138] While in the description given above, positioning is
performed by applying light from below the substrates, it is
considered to apply light from above the substrates. For example,
as shown in FIG. 1, when under a condition where the waveguide
substrate 1, the lens substrate 3, the isolator substrate 8 and the
lens substrate 10 are laminated, the waveguide substrate 12 is
further laminated on the lens substrate 10 and positioning of the
lens substrate 10 and the waveguide substrate 11 is performed, the
light source 105 and the light receiver 106 are disposed above the
waveguide substrate 11 and the light receiver 106 is disposed at a
side of the lens substrate 10 and the waveguide substrate 11. At
this time, markers 101 of which bottom surfaces 102 are inclined
scattering surfaces are used. When light is applied from above the
waveguide substrate 11, at the part where the markers 101 are
absent, the light is reflected by the isolator substrate 11, and at
the part where the markers 101 are present, the light is reflected
sideward. Consequently, on the light receiver 106 disposed above
the waveguide substrate 11, images similar to those shown in FIG.
12(b) are projected. On the light receiver 106 disposed at a side
of the waveguide substrate 11, images similar to those shown in
FIG. 12(c) are projected. By doing this, positioning of the
substrates in the horizontal direction and positioning thereof in
the vertical direction can be performed at the same time by
applying light from above the substrates.
[0139] (Second Embodiment)
[0140] Next, a second embodiment of the present invention will be
described with reference to FIG. 3.
[0141] In the three-dimensional optical waveguide shown in FIG. 3,
a waveguide substrate 31 has two waveguides 22 and 32. Here, the
waveguide 32 is disposed on the farther side from the plane of FIG.
3 so as to be parallel to the waveguide 22. The waveguide 22 has a
reflecting surface 313 at its end, and the waveguide 32 has a
reflecting surface 333 at its end. The lens substrate 33 has a lens
34 corresponding to the reflecting surface 313 and a lens 304
corresponding to the reflecting surface 333.
[0142] Above the isolator substrate 8, a lens substrate 30 having a
lens 29 corresponding to the lens 34 is laminated, and above the
lens substrate 30, a waveguide substrate 31 is laminated having a
waveguide 312 and a reflecting surface 314 disposed at an end of
the waveguide 312 and corresponding to the lens 29. Above the
waveguide substrate 31, a lens substrate 300 having a lens 209
corresponding to the lens 304 is laminated, and above a lens
substrate 300, a waveguide substrate 301 is laminated having a
waveguide 302 and a reflecting surface 324 disposed at an end of
the waveguide 302 and corresponding to the lens 209.
[0143] Here, the reflecting surfaces 313 and 333 are angled at
45.degree. like the reflecting surface 13 in the first embodiment,
and the reflecting surfaces 314 and 324 are angled 45.degree. like
the reflecting surface 14 in the first embodiment. Like in the
first embodiment, the horizontal positions of the reflecting
surface 313, the lens 34, the lens 29 and the reflecting surface
314 are aligned in the vertical direction, and the horizontal
positions of the reflecting surface 333, the lens 304, the lens 209
and the reflecting surface 324 are aligned in the vertical
direction.
[0144] Here, positioning of the waveguide substrate 31 and the lens
substrate 33, positioning of the lens substrate 33 and the lens
substrate 30, positioning of the lens substrate 30 and the
waveguide substrate 31, positioning of the waveguide substrate 31
and the lens substrate 300 and positioning of the lens substrate
300 and the waveguide substrate 301 are performed similarly to the
first embodiment (the same applied to the embodiments described
below).
[0145] By structuring the three-dimensional optical waveguide as
described above, the lights directed into the waveguides 22 and 32
of the waveguide substrate 31 are directed to the waveguides 312
and 302, respectively, by an action similar to that of the first
embodiment. As described above, by laminating the planar substrates
of the present invention and three-dimensionally forming two
waveguides, a low-cost and high-performance three-dimensional
optical waveguide not requiring a complicated adjustment is
provided.
[0146] While in the second embodiment, the lens substrate 30 is
present between the isolator substrate 8 and the waveguide
substrate 31 and the lens substrate 300 is present between the
waveguide substrate 31 and the waveguide substrate 301, when it is
possible that the light reflected by the reflecting surface 313 is
condensed on the reflecting surface 314 only by the lens 44 and the
light reflected by the reflecting surface 333 is condensed on the
reflecting surface 324 only by the lens 404 as shown in FIG. 4, the
lens substrates 30 and 300 are unnecessary. In that case, similar
effects to those described above are obtained.
[0147] While in the second embodiment, the waveguide 32 is disposed
on the farther side from the plane of FIG. 3 so as to be parallel
to the waveguide 22, the arrangement of the waveguides 22 and 32 is
not limited thereto. Similar effects to those described above are
obtained from any arrangement as long as the waveguides 22 and 32
are separately disposed on the same waveguide substrate 31 and the
lights directed thereinto are directed to the other waveguides 312
and 302, respectively.
[0148] The waveguides 22 and 32 are not necessarily present on the
same waveguide substrate 31 but may be present on different
laminated waveguide substrates, and the waveguides 312 and 302 are
not necessarily present on the waveguide substrates 31 and 301 but
may be present on the same waveguide substrate. In these cases,
similar effects to those described above are obtained.
[0149] (Third Embodiment)
[0150] FIG. 5 shows the structure of a three-dimensional optical
waveguide according to a third embodiment of the present
invention.
[0151] In the three-dimensional optical waveguide of the present
embodiment, a surface emitting laser (VCSEL) 59 which is the light
emitting element of the present invention is disposed above the
isolator substrate 8, and a reflecting surface 513, a lens 54 and
the surface emitting laser 59 are disposed so that the horizontal
positions thereof are aligned in the vertical direction. Here, the
structure of the part constituted by a waveguide substrate 51, a
lens substrate 53 and the isolator substrate 8 is similar to that
of the first embodiment, and description thereof is omitted.
[0152] According to the above-described structure, the laser beam
emitted from the surface emitting laser 59 passes through the
isolator substrate 8 and the lens 54 to be directed to the
waveguide 52 of the waveguide substrate 51. By doing this, a
low-cost and high-performance three-dimensional optical waveguide
not requiring a complicated adjustment is provided.
[0153] While in the third embodiment, the isolator substrate 8 is
present between the lens substrate 53 and the surface emitting
laser 59, the isolator substrate 8 is not necessarily present. In
that case, similar effects to those described above are
obtained.
[0154] While the above description is given with reference to an
example in which the surface emitting laser 59 is disposed above
the isolator substrate 8, as shown in FIG. 6, a surface-mount
photodiode 69 which is the light receiving element of the present
invention may be disposed instead of the surface emitting laser 59.
FIG. 6 shows a three-dimensional optical waveguide comprising a
waveguide substrate 61 having a waveguide 62, a lens substrate 63
having a lens 64 and the surface-mount photodiode 69. Here, the
structure of the waveguide substrate 61 and the lens substrate 63
is similar to the above-described structure, and description
thereof is omitted. In the structure shown in FIG. 6, the isolator
substrate 8 may be laminated between the lens substrate 63 and the
surface-mount photodiode 69.
[0155] (Fourth Embodiment)
[0156] FIG. 7 shows the structure of a three-dimensional optical
waveguide according to a fourth embodiment of the present
invention.
[0157] In the three-dimensional optical waveguide of the fourth
embodiment, a waveguide substrate 71 has a waveguide 72, and a
waveguide 702 in a direction opposed to the waveguide 72. At an end
of the waveguide 72, a reflecting surface 713 is formed, and at an
end of the waveguide 702, a reflecting surface 733 is formed. Here,
the reflecting surfaces 713 and 733 are formed so as to be opposed
to each other and each angled at approximately 22.5.degree. from
the horizontal plane in a direction that forms a slope of a
trapezoidal shape. On a lens substrate 73 laminated above the
waveguide substrate 71, a lens 74 and a lens 704 are formed
integrally with the lens substrate 73 so as to adjoin each
other.
[0158] Above the lens substrate 73, a wavelength division
multiplexing filter 76 which is the planar substrate having a
filter layer of the present invention is laminated, and above the
wavelength division multiplexing filter 76, a lens substrate 70
having a lens 79 is laminated. Above the lens substrate 70, a
waveguide substrate 711 is laminated having a waveguide 712 and a
reflecting surface 714 formed at an end of the waveguide 712. Here,
the reflecting surface 714 is angled at approximately 22.5.degree.
from the horizontal plane. When viewed from the reflecting surface
713, the lens 74, the lens 79 and the reflecting surface 714 are
aligned so as to be inclined toward the upper left by 45.degree.
from the horizontal plane. When viewed from the reflecting surface
733, the lens 704 is inclined by 45.degree. from the horizontal
direction in a direction slanting upward toward the right.
[0159] The operation of the three-dimensional optical waveguide
structured as described above will be described next.
[0160] The light traveling leftward in the horizontal direction
through the waveguide 72 is reflected upward by the reflecting
surface 713 at 45.degree. from the horizontal travel direction, and
passes through the lens 74. Part of the light having passed through
the lens 74 passes through the wavelength division multiplexing
filter 76 (that is, is sorted out by the wavelength division
multiplexing filter), reaches the reflecting surface 714 through
the lens 79 to be reflected in the horizontal direction, and
travels leftward through the waveguide 712. The light including the
remaining wavelength component sorted out by the wavelength
division multiplexing filter 76 is reflected at 45.degree. from the
horizontal direction in a direction slanting downward toward the
left at the interface between the lens substrate 73 and the
wavelength division multiplexing filter 76, is reflected by the
reflecting surface 733 through the lens 704, and travels leftward
in the horizontal direction through the waveguide 702.
[0161] As described above, according to the three-dimensional
optical waveguide of the present embodiment, the light incident on
the waveguide 72 can be extracted after being separated between
light traveling through the waveguide 712 and light traveling
through the waveguide 702 according to the wavelength
component.
[0162] In the present embodiment, when it is possible that light is
sufficiently condensed on the reflecting surface 714 by the lens
74, the lens substrate 70 is unnecessary. In that case, similar
effects to those described above are obtained.
[0163] FIG. 8 shows a modification of the present embodiment. In
this modification, above the lens substrate 70, a surface-mount
photodiode 89 is disposed instead of laminating the waveguide
substrate 711. By doing this, it is possible that, of the light
incident on the waveguide 72, only the light of the wavelength
component sorted out by the wavelength division multiplexing filter
76 is directed into the surface-mount photodiode 89 and the light
of the wavelength component not sorted out by the wavelength
division multiplexing filter 76 is directed into the other
waveguide 702.
[0164] When the three-dimensional optical waveguide of the present
embodiment is formed, positioning of the substrates is performed by
applying light from above the three-dimensional optical waveguide
as required. For example, in a case where positioning of the
waveguide substrate 711 is performed under a condition where the
waveguide substrate 71, the lens substrate 73, the wavelength
division multiplexing filter 76 and the lens substrate 70 are
laminated as shown in FIG. 7, when the wavelength of the light
emitted from the light source 105 does not pass through the
wavelength division multiplexing filter 76, the light source 105 is
disposed above the waveguide substrate 711, and positioning of the
waveguide substrate 711 is performed by applying light from above
by a method similar to that described in the first embodiment.
[0165] (Fifth Embodiment)
[0166] FIG. 9 shows the structure of a three-dimensional optical
waveguide of the present invention according to a fifth
embodiment.
[0167] The three-dimensional optical waveguide of the present
embodiment has on the left side thereof a three-dimensional optical
waveguide where a lens substrate 900 having a lens 919 is laminated
above the three-dimensional optical waveguide shown in the third
embodiment (FIG. 5), and has on the right side thereof the
three-dimensional optical waveguide shown in the fourth embodiment
(FIG. 8). Here, the thickness of the lens substrate 900 is
different between the left side and the right side thereof. The
thickness of the right side of the three-dimensional optical
waveguide of the present embodiment is larger than that of the left
side by the thickness of a Faraday rotator 96 and the thickness of
a polarizer 97. Moreover, a wavelength division multiplexing filter
906 is designed so as to reflect the wavelength of the light
emitted from a surface emitting laser 99 and transmit the
wavelength of the light incident from a waveguide 92. The elements
other than these are similar to those of the third and the fourth
embodiments, and description thereof is omitted.
[0168] In the three-dimensional optical waveguide having such a
structure, the light traveling leftward through the waveguide 92 is
reflected upward by a reflecting surface 913 at 45.degree. from the
horizontal travel direction, passes through a lens 94, the
wavelength division multiplexing filter 906 and a lens 909, and
reaches a surface-mount photodiode 999. The light emitted from the
surface emitting laser 99 passes downward through the lens 919, an
isolator substrate 98 and a lens 914, is reflected rightward in the
horizontal direction by a reflecting surface 943, and is then
reflected upward by a reflecting surface 933 in a direction
45.degree. from the direction of travel. The light reflected by the
reflecting surface 933 passes through a lens 904, is reflected at
45.degree. in a direction slanting downward toward the right at the
interface between the wavelength division multiplexing filter 906
and a lens substrate 93, passes through the lens 94, and reaches
the reflecting surface 913. The light reflected rightward in the
horizontal direction by the reflecting surface 913 travels
rightward through the waveguide 92.
[0169] As described above, according to the present embodiment, a
low-cost and high-performance three-dimensional optical waveguide
is provided that does not require a complicated adjustment although
having a complicated structure.
[0170] (Sixth Embodiment)
[0171] FIG. 10 shows the structure according to a sixth embodiment
of the present invention.
[0172] The structure of the right side of the three-dimensional
optical waveguide shown in FIG. 10 is similar to the structure of
the three-dimensional optical waveguide shown in the second
embodiment (FIG. 3), and description thereof is omitted. The
structure of the left side of the three-dimensional optical
waveguide shown in FIG. 10 is one obtained by vertically and
horizontally reversing the structure of the three-dimensional
optical waveguide shown in the fourth embodiment (FIG. 7). Here, a
wavelength division multiplexing filter 1316 which is an example of
the wavelength division multiplexing filter of the present
invention is set so as to transmit light of a wavelength .lambda.1
and not to transmit light of a wavelength .lambda.2.
[0173] In the three-dimensional optical waveguide having such a
structure, when lights of the different wavelengths .lambda.1 and
.lambda.2 are directed into waveguides 1322 and 1332, respectively,
the light of the wavelength .lambda.1 directed into the waveguide
1322 reaches a reflecting surface 1373 through a reflecting surface
1313, a lens 1334, an isolator substrate 1308, a lens 1324, a
reflecting surface 1363 and a waveguide 1342. The light reflected
by the reflecting surface 1373 passes through a lens 1344, the
wavelength division multiplexing filter 1316 and a lens 1364, is
reflected by a reflecting surface 1393, and reaches a waveguide
1362.
[0174] The light of the wavelength .lambda.2 directed into the
waveguide 1332 reaches a reflecting surface 1383 through a
reflecting surface 1333, a lens 1304, the isolator substrate 1308,
a lens 1314 and a reflecting surface 1353. The light reflected by
the reflecting surface 1383 is incident, through a lens 1354, on
the wavelength division multiplexing filter 1316 from the upper
right in a slanting direction. Since the wavelength division
multiplexing filter 1316 does not transmit light of the wavelength
.lambda.2, the light incident from the upper right of the
wavelength division multiplexing filter 1316 in a slanting
direction is reflected at the interface between the wavelength
division multiplexing filter 1316 and a lens substrate 1350,
travels in a direction slanting upward toward the left, and is
directed into a waveguide 1362 through the lens 1364 and the
reflecting surface 1393.
[0175] When the lights of the wavelengths .lambda.1 and .lambda.2
are directed into the waveguides 1322 and 1332 as described above,
light having the wavelength components of .lambda.1 and .lambda.2
is output from the waveguide 1362. As described above, according to
the present embodiment, a low-cost and high-performance
three-dimensional optical waveguide is provided that does not
require a complicated adjustment although having a complicated
structure.
[0176] (Seventh Embodiment)
[0177] Using any of the three-dimensional optical waveguides shown
in the above-described embodiments, a module transmitting and
receiving light can be formed. FIG. 19 is an example of the
structure of such an optical transmitter module. As shown in FIG.
19, to an electric input terminal 1105 which is an example of the
electric input terminal of the present invention, a laser diode
1109 which is an example of the light emitting element of the
present invention is connected. The laser diode 1109 is connected
to a waveguide 1102. The waveguide 1102 is connected to a waveguide
1112 through an isolator 1108. To the waveguide 1112, an optical
output terminal 1107 which is an example of the optical output
terminal of the present invention is connected. Such an optical
transmitter module can be formed, for example, by using the
three-dimensional optical waveguide shown in FIG. 1 which is an
example of the three-dimensional optical waveguide of the present
invention. In this case, the waveguide 1102 in FIG. 19 corresponds
to the waveguide 2 shown in FIG. 1, and to an end thereof, the
laser diode 1109 (in this case, an edge emitting laser) is
attached. The waveguide 1112 in FIG. 19 corresponds to the
waveguide 12 shown in FIG. 1, and at an end thereof, for example, a
V groove 1042 shown in FIG. 25 is disposed as the optical output
terminal 1107, and an optical fiber cable (not shown) is fixed.
[0178] By doing this, an optical output can be output from the
output terminal 1107 in accordance with the electric signal input
to the electric input terminal 1105, so that a low-cost optical
transmitter module not requiring a complicated adjustment is
provided.
[0179] Instead of using the three-dimensional optical waveguide
shown in FIG. 1, the three-dimensional optical waveguide shown in
FIG. 2 may be used. Moreover, the three-dimensional optical
waveguide as shown in FIG. 3 or FIG. 4 may be used. In that case,
the two waveguides 22 and 32 correspond to the waveguide 1102, and
the two waveguides 312 and 302 correspond to the waveguide 1112. At
an end of each of the waveguides 22 and 32, the laser diode 1109 is
disposed, and to an end of each of the waveguides 312 and 302, the
optical output terminal 1107 is connected. The light emitted from
each laser diode 1109 is output from the optical output terminal
1107. Moreover, the three-dimensional optical waveguide shown in
FIG. 5 may be used. In that case, the waveguide 1102 is omitted,
and as the laser diode 1109, the surface emitting laser 59 is
used.
[0180] Moreover, FIG. 20 shows an example of the structure of a
wavelength division multiplexing optical transmitter module. The
wavelength division multiplexing optical transmitter module shown
in FIG. 20 has two laser diodes 1119 and 1129 each having the
electric input terminal 1105. To the laser diodes 1119 and 1129,
the waveguides 1132 and 1142 are connected, respectively. The
waveguides 1132 and 1142 are connected to waveguides 1152 and 1162
through an isolator 1118, respectively. The waveguides 1152 and
1162 are connected to the optical output terminal 1107 through the
wavelength division multiplexing filter 1106.
[0181] Such a wavelength division multiplexing optical transmitter
module can be formed, for example, by using the three-dimensional
optical waveguide of the structure shown in FIG. 10. In this case,
the laser diode 1119 outputting light of the wavelength .lambda.1
is disposed at an end of the waveguide 1322, and the laser diode
1129 outputting light of the wavelength .lambda.2 is disposed at an
end of the waveguide 1332. The output terminal 1107 is disposed at
an end of the waveguide 1362.
[0182] By doing this, the electric signals input from the two laser
diodes 1119 and 1129 can be output as combined with each other as
an optical signal.
[0183] (Eighth Embodiment)
[0184] FIG. 21 shows an example of the structure of an optical
receiver module. As shown in FIG. 21, an optical input terminal
1117 (for example, the V groove shown in FIG. 25) which is an
example of the optical input terminal of the present invention is
disposed at an end of a waveguide 1122, and a photodiode 1209 which
is an example of the light receiving element of the present
invention is connected to the waveguide 1122. To the photodiode
1209, an electric output terminal 1115 which is an example of the
electric output terminal of the present invention is connected.
Such an optical receiver module can be structured, for example, by
using the three-dimensional optical waveguide shown in FIG. 6 which
is an example of the three-dimensional optical waveguide. According
to the optical receiver module having such a structure, electric
output can be obtained from the electric output terminal 1115 in
accordance with the optical signal input to the optical input
terminal 1117.
[0185] FIG. 22 shows an example of the structure of a wavelength
division multiplexing optical receiver module. In this structure
example, the optical input terminal 1117 is connected to the
wavelength division multiplexing filter 1116, waveguides 1172 and
1182 are connected to the wavelength division multiplexing filter
1116, and photodiodes 1219 and 1229 are connected to the waveguides
1172 and 118, respectively.
[0186] Such a wavelength division multiplexing optical receiver
module can be structured, for example, by using the
three-dimensional optical waveguide shown in FIG. 7. In this case,
the optical input terminal 1117 is connected to an end of the
waveguide 72, and the photodiodes 1219 and 1229 are connected to
ends of the waveguides 712 and 702, respectively. The wavelength
division multiplexing filter 76 is set so as to transmit light of
the wavelength .lambda.1 and not to transmit light of the
wavelength .lambda.2.
[0187] In the wavelength division multiplexing optical receiver
module having such a structure, when lights of the wavelength
.lambda.1 and the wavelength .lambda.2 are directed into the
waveguide 71, the light of the wavelength .lambda.1 reaches the
photodiode 1219 through the waveguide 712, the light of the
wavelength .lambda.2 reaches the photodiode 1229 through the
waveguide 702, and in accordance therewith, electric output is
output from the electric output terminal 1115 connected to each of
the photodiodes 1219 and 1229. That is, an optical signal input
from one optical input terminal 1117 can be obtained from each
electric output terminal 1115 as two separate electric signals.
[0188] The above-described optical transmitter module and optical
receiver module can be used as an optical transmission system for
transmission and reception by being connected through an optical
fiber cable.
[0189] (Ninth Embodiment)
[0190] FIG. 23 shows an example of the structure of a wavelength
division multiplexing optical transmitter and receiver module
having both an optical transmission function and an optical
reception function. In the structure shown in FIG. 23, a laser
diode 1139 having the electric input terminal 1105 and emitting
light of the wavelength .lambda.1 is connected to a wavelength
division multiplexing filter 1126 which is an example of the
wavelength division multiplexing filter of the present invention
through a waveguide 1192, an isolator 1128 which is an example of
the isolator of the present invention and a waveguide 1212. The
photodiode 1239 having the electric output terminal 1115 and
receiving light of the wavelength .lambda.2 is connected to the
wavelength division multiplexing filter 1126 through a waveguide
1202. To the wavelength division multiplexing filter 1126, an
optical input and output terminal 1127 (for example, the V groove
shown in FIG. 25) which is an example of the optical input and
output terminal of the present invention is connected.
[0191] Such a wavelength division multiplexing optical transmitter
and receiver module can be structured, for example, by using the
three-dimensional optical waveguide shown in FIG. 9. In this case,
the optical input and output terminal 1127 is disposed at an end of
the waveguide 92. The wavelength division multiplexing filter 906
is set so as not to transmit light of the wavelength .lambda.1
emitted from the surface emitting laser 99 and to transmit light of
the wavelength .lambda.2 input to the optical input and output
terminal 1127.
[0192] According to this structure, the light of the wavelength
.lambda.1 emitted from the surface emitting laser 99 is reflected
at the interface between the wavelength division multiplexing
filter 906 and the lens substrate 93, and is output from the
optical input and output terminal 1127 through the waveguide 92.
The light of the wavelength .lambda.2 input to the optical input
and output terminal 1127 passes through the wavelength division
multiplexing filter 906 to reach the surface-mount photodiode 999.
According to such a wavelength division multiplexing optical
transmitter and receiver module, light can be transmitted and
received with only one optical input and output terminal 1127.
[0193] FIG. 24 shows an example of a light transmission apparatus
using such a wavelength division multiplexing optical transmitter
and receiver module. In FIG. 24, to the laser diode 1149, a laser
diode driver IC 1104 is connected, and to the laser diode driver IC
1104, a transmission signal multiplexer 1103 is connected. To the
transmission signal multiplexer 1103, an electric signal input
terminal 1125 for inputting a plurality of signals is connected.
The laser diode driver IC 1104 controls the current bias supplied
to the laser diode, and superimposes digital signals.
[0194] On the other hand, to a photodiode 1249, a reception front
end IC 1114 is connected, and to the reception front end IC 1114, a
reception signal demultiplexer 1113 is connected. To the reception
signal demultiplexer 1113, a reception signal output terminal 1135
for outputting a plurality of signals is connected. The reception
front end IC 1114 low-noise-amplifies the faint signal output from
the photodiode 1249.
[0195] In FIG. 24, the laser diode 1149 and the elements disposed
on the right side of the photodiode 1249 are as described above. By
using such an optical transmission apparatus, a plurality of
electric signals can be transmitted on an optical fiber cable
through one optical input and output terminal.
[0196] A plurality of the above-described optical modules for
transmission and reception can be used as an optical transmission
system for transmission and reception by being connected through an
optical fiber cable. In this case, for example, two optical modules
for transmission and reception prepared as a pair can be used as a
pair of optical transmission systems for transmission and reception
by making a setting such that one optical transmitter and receiver
module performs transmission at the wavelength .lambda.1 and
reception at the wavelength .lambda.2 and the other optical
transmitter and receiver module performs transmission at the
wavelength .lambda.2 and reception at the wavelength .lambda.1.
[0197] While in the description given above, the top, the bottom,
the right and the left are fixed to those shown in the figures,
they may be different from those described above as long as similar
effects are obtained.
[0198] While in the description given above, light from a
horizontal direction is made to travel in the vertical direction or
at an angle of 45.degree., these are merely examples. The light may
be made to travel at an arbitrary angle with respect to the
laminated substrates. In that case, the angles of the reflecting
surfaces and the arrangement of the lenses and the reflecting
surfaces are settable so that the light travels in such a
manner.
[0199] While in the above-described embodiments, the substrates are
formed of forming glass, the present invention is not limited
thereto; they may be formed of resin or the like. The substrates
may be formed, for example, by forming the markers 101 and 103 at
the same time together with the waveguides on a silicon substrate
by dry etching. In that case, similar effects to those described
above are obtained.
[0200] In the above-described embodiments, the planar substrates
other than the one having a waveguide may be sheet optical elements
in addition to or instead of the lens layer, the isolator layer and
the filter layer. Examples of such sheet optical elements include a
sheet attenuator attenuating optical power.
[0201] According to the present invention, a low-cost
three-dimensional optical waveguide not requiring a complicated
adjustment can be provided.
[0202] Moreover, when the planar waveguide, and the lens layer, the
isolator layer or the filter layer are integrally formed on forming
glass, a low-cost three-dimensional optical waveguide further not
requiring a complicated adjustment can be provided.
[0203] Moreover, when the planar substrate has the lens layer, the
isolator layer or the filter layer, a high-performance
three-dimensional optical waveguide can be provided.
[0204] Moreover, according to the method of manufacturing a
three-dimensional optical waveguide of the present invention, a
precise and low-cost three-dimensional optical waveguide not
requiring a complicated adjustment can be provided.
[0205] Moreover, according to the optical module having the
three-dimensional optical waveguide of the present invention, a
low-cost optical module not requiring a complicated adjustment can
be provided.
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