JP2005003855A - Bi-directional optical communication module, optical waveguide element, and bi-directional optical communication module device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To effectively suppress an optical cross talk and an electric cross talk in a bi-directional optical communication module and to make the module easily compatible to the increase in the number of light emitting/light receiving parts. <P>SOLUTION: The module has: a light emitting part 1; a light receiving part 3; a transmission optical waveguide 5-1 which guides transmission light emitted from the light emitting part 1 to the connected end face of an optical fiber 6 corresponding to the pair of the light emitting part 1 and the light receiving part 3, and makes incident into the optical fiber 6 from the connected end face; and a receiving optical waveguide 5-2 which guides receiving light emitted from the connected end face of the optical fiber 6 to the light receiving part 3 corresponding to the optical fiber 6. The transmission optical waveguide 5-1 is formed in a transmission optical waveguide layer 7, the receiving optical waveguide 5-2 is formed in a receiving optical waveguide layer 8, the transmission optical waveguide layer 7 and the receiving optical waveguide layer 8 are both laminated in the thickness direction and integrated as a plate-shaped optical waveguide element 5, the transmission optical waveguide and the receiving optical waveguide are closely laminated coaxially with the fiber at the connected end face part on the side of the optical fiber 6, and separately formed by the amount of the gap between the light emitting part 1 and the light receiving part 3 on the side of the light emitting part 1/the light receiving part 3. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a bidirectional optical communication module, an optical waveguide element, and a bidirectional optical communication module apparatus.
[0002]
[Prior art]
As a bidirectional optical communication module, conventionally, a light emitting element and a light receiving element, a transmission optical waveguide and a reception optical waveguide are integrated on a silicon substrate, and transmission / reception is performed using a single optical fiber. A module is known (Patent Document 1).
[0003]
In this bidirectional optical communication module, the light emitting element and the light receiving element are mounted close to each other on the same substrate, so that light emitted from the light emitting element is directly incident on the light receiving element and crosstalk is suppressed. A shielding plate is disposed between the element and the light receiving element.
[0004]
However, since the light emitting element and the light receiving element are arranged close to “a distance within the core diameter of the optical fiber”, it is difficult to completely suppress optical crosstalk even if a light shielding plate is used. Further, electrical crosstalk due to the close arrangement of the light emitting element and the light receiving element is a serious problem particularly in a high-speed transmission band of Gbps (1 gigabit per second) or more.
[0005]
Further, when considering application to “parallel high-speed transmission using an optical fiber array” of the bidirectional optical communication module described in Patent Document 1, how to arrange a plurality of light emitting elements / light receiving elements as the number of arrays increases is a problem. It becomes.
[0006]
[Patent Document 1]
JP 2000-162455 A
[0007]
[Problems to be solved by the invention]
It is an object of the present invention to effectively suppress optical crosstalk and electrical crosstalk in a bidirectional optical communication module and easily cope with an increase in the number of light emitting units and light receiving units.
[0008]
[Means for Solving the Problems]
The bidirectional optical communication module according to the present invention includes N (≧ 1) light emitting portions Hi (i = 1 to N), N light receiving portions Si (i = 1 to N), and N transmitting light guides. It has a waveguide HDi and N receiving optical waveguides SDi.
[0009]
The N light emitting units Hi radiate optical signals for transmission.
[0010]
The N light receiving portions Si have a function of receiving an optical signal and converting it into an electrical signal, and correspond to N light emitting portions Hi and 1: 1. That is, with i = 1 to N, the light receiving portion Si corresponds to the light emitting portion Hi.
[0011]
Each of these “pairs of the light emitting portion Hi and the light receiving portion Si” corresponds to one optical fiber. That is, N optical fibers correspond to “N pairs of light emitting portions Hi and light receiving portions Si” corresponding to 1: 1.
[0012]
Each of the transmission optical waveguides HDi constituting the N transmission optical waveguides guides the light emitted from the light emitting portion Hi to the coupling end face of the optical fiber Fi corresponding to the light emitting section Hi, and the optical fiber from the coupling end face Incident into Fi.
[0013]
Each of the reception optical waveguides SDi constituting the N reception optical waveguides guides and receives the reception light emitted from the coupling end face of the optical fiber Fi corresponding to the light reception unit Si to the light reception unit Si.
[0014]
The bidirectional optical communication module of the present invention is characterized by the following points.
That is, N transmission optical waveguides HDi are formed in “the same transmission optical waveguide layer”, and N reception optical waveguides SDi are formed in “the same reception optical waveguide layer”. The trusted optical waveguide layer and the receiving optical waveguide layer are laminated in the thickness direction and integrated as a plate-like “optical waveguide element”.
[0015]
Then, the transmission optical waveguide HDi (= 1 to N) and the reception optical waveguide SDi (i = 1 to N) are laminated close to each other on the fiber coaxial side at the coupling end surface portion on the optical fiber Fi side, and the light emitting portion Hi. On the side and the light receiving part Si side, the light emitting part Hi and the light receiving part Si are formed so as to be separated from each other in the direction perpendicular to the thickness direction of the optical waveguide element by the distance between the light emitting part Hi and the light receiving part Si.
[0016]
In the bidirectional optical communication module according to claim 1, it is preferable that the optical fiber Fi (i = 1 to N) to be optically coupled is a multimode optical fiber (claim 2). The light emitting portion Hi (1 = 1 to N) in the bidirectional optical communication module according to claim 1 or 2 can be a “light emitting surface of a surface emitting laser” (claim 3).
[0017]
The bidirectional optical communication module according to any one of claims 1 to 3 can be configured such that the light emitting portion Hi and the light receiving portion Si (i = 1 to N) are “mounted on the same substrate” ( Claim 4).
[0018]
The bidirectional optical communication module according to any one of claims 1 to 4, wherein the number N of light emitting portions, light receiving portions, transmitting optical waveguides, and receiving optical waveguides may be one (Claim 5). In this case, the light emitting part is a light emitting part of a single light emitting element (for example, the “surface emitting laser”), and the light receiving part is a light receiving part (light receiving surface) of the single light receiving element.
[0019]
5. The bidirectional optical communication module according to claim 1, wherein the number N of the light emitting part, the light receiving part, the transmitting optical waveguide, and the receiving optical waveguide: N can be “2 or more” (claim) Item 6). In this case, the plurality of light emitting units / light receiving units can be individual light emitting elements / light receiving units, but N (≧ 2) light emitting units may be integrally arranged in an array. ). Further, in the bidirectional optical communication module according to claim 6 or 7, N (≧) light receiving portions may be integrally arranged in an array (claim 8).
[0020]
The optical waveguide element in the bidirectional optical communication module according to any one of claims 1 to 8, wherein "the N core portions having a higher refractive index than the transparent substrate are arranged on the transparent substrate, the transmitting optical waveguide portion. Optical waveguide substrate for transmission formed as “the optical waveguide substrate for reception formed with N core portions having a refractive index higher than that of the transparent substrate on the other transparent substrate as the optical waveguide portion for reception” Can be configured so that the side where each core part is formed is opposed and between each transparent substrate is filled with “adhesive having substantially the same refractive index as each transparent substrate” to be integrated (claim). Item 9).
[0021]
In the bidirectional optical communication module according to claim 9, in the optical waveguide element, "a waveguide portion by a core portion formed on one transparent substrate" and "a waveguide portion by a core portion formed on the other transparent substrate" And “opposing each other through the light shielding film” (claim 10).
[0022]
An optical waveguide device according to an eleventh aspect is an optical waveguide device used in the bidirectional optical communication module according to the ninth or tenth aspect. In the optical waveguide device according to claim 11, the number of transmitting optical waveguides / receiving optical waveguides: N may be N = 1 (Claim 12) or N ≧ 2 (Claim 13). You can also.
[0023]
The bidirectional optical communication module device according to the present invention is a combination of the bidirectional optical communication module according to any one of claims 1 to 10 and N optical fibers (claim 14). In this case, one end of the optical fiber is coupled to the bidirectional optical communication module, but the other end of the optical fiber may be coupled to another bidirectional optical communication module (in this case, bidirectional optical communication). Bidirectional optical communication can be performed by the module device), and may be coupled to a connector.
[0024]
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 shows an embodiment.
1A is a plan view, and FIG. 1B is a side view.
In FIG. 1A, reference numeral 1 denotes a light emitting element. As the light emitting element 1, an edge emitting type or surface emitting type semiconductor laser or LED can be used. In this embodiment, a “surface emitting laser (surface emitting type semiconductor laser)” is used. . The light emitting element 1 is driven by the drive circuit 2 in accordance with the transmission signal, and emits laser light from the light emitting surface which is the “light emitting portion”.
[0025]
In FIG. 1A, reference numeral 3 denotes a light receiving element. The light receiving element 3 generates an electrical signal corresponding to the amount of received light when the light receiving surface which is the “light receiving portion” receives light. This electric signal is amplified by the amplifier circuit 4.
As shown in FIG. 1A, the light emitting element 1, the drive circuit 2, the light receiving element 3, and the amplifier circuit 4 are mounted on the same support substrate 10.
[0026]
In FIG. 1, reference numeral 5 denotes an “optical waveguide element”. Reference numeral 6 denotes an optical fiber. The optical waveguide element 5 is “plate-shaped” as shown in FIGS. 1A and 1B. As shown in FIG. 1B, the optical waveguide layer for transmission 7 and the optical waveguide layer for reception 8 are made up of. , Laminated in the thickness direction and integrated. The optical fiber 6 is a “multimode optical fiber”.
[0027]
The transmission optical waveguide 5-1 is formed in the transmission optical waveguide layer 7, and the reception optical waveguide layer 5-2 is formed in the reception optical waveguide layer 8.
As shown in FIGS. 1A and 1B, the transmission optical waveguide 5-1 and the reception optical waveguide 5-2 are laminated close to each other on the fiber coaxial side at the coupling end face portion on the optical fiber 6 side. The end portions of these waveguides are all opposed to the coupling end face of the optical fiber 6.
Further, the transmitting optical waveguide 5-1 and the receiving optical waveguide 5-2 are arranged on the light emitting element 1 and light receiving element 2 side in a direction perpendicular to the thickness direction of the plate-shaped optical waveguide element 5 (up and down in FIG. 1A). (The direction perpendicular to the drawing of FIG. 1B) is formed so as to be separated by “the distance between the light emitting portion of the light emitting element 1 and the light receiving portion of the light receiving element 2”.
[0028]
Since the transmission optical waveguide layer 7 and the reception optical waveguide layer 8 are laminated in the thickness direction, the transmission optical waveguide 5-1 and the reception optical waveguide 5-2 are arranged on the light emitting element / light reception element side ( Also on the left side of FIG. 1, the light is separated in the thickness direction, and the light emitting portion of the light emitting element 1 and the light receiving portion of the light receiving element 3 have “steps” in the thickness direction according to the amount of separation in the thickness direction.
[0029]
When a “transmission optical signal” is emitted from the light emitting portion of the light emitting element 1, this optical signal is transmitted to the optical waveguide for transmission 5-1 formed in the optical waveguide element 5 (the end on the light emitting element 1 side is the light emitting portion). The light is incident into the transmission optical waveguide 5-1, guided to the other end side in the transmission optical waveguide 5-1, and coupled to the other end portion. The light enters the optical fiber 6 from the coupling end face of the fiber 6 and is coupled and transmitted through the optical fiber 6.
[0030]
When the “receiving optical signal” is transmitted through the optical fiber 6 from “right to left in the figure”, this optical signal is received from the coupling end face of the optical fiber 6 to the receiving optical waveguide 5-2. Then, the light is guided to the light receiving element 3 side, exits from the end face on the light receiving element 3 side, enters the light receiving face of the light receiving element 1 that is in close proximity to the end face, and generates a light receiving signal. This received light signal is amplified by the amplifier circuit 4 to be a received signal.
[0031]
In this way, in the embodiment of FIG. 1, “bidirectional optical communication” of transmission / reception can be performed by one optical fiber 6.
[0032]
Further, the transmission optical waveguide 5-1 and the reception optical waveguide 5-2 can be separated from each other in the “direction orthogonal to the thickness direction of the optical waveguide element 5” on the light emitting element 1 / light receiving element 3 side. Therefore, the optical signal radiated from the light emitting unit can be prevented from entering the light receiving unit, and optical crosstalk can be effectively prevented.
[0033]
That is, the bidirectional optical communication module whose embodiment is shown in FIG. 1 includes N (= 1) light emitting portions Hi (light emitting surface of the light emitting element 1), and light receiving portions corresponding to the light emitting portions in a ratio of 1: 1. Transmitted light radiated from the light emitting portion Hi to the coupling end surface of the optical fiber Fi (6) corresponding to 1: 1 with the light emitting portion Hi corresponding to Si (the light receiving surface of the light receiving element 3) and the pair of light receiving portions Si. The transmission optical waveguide HDi (5-1) that enters the optical fiber Fi (6) from the coupling end face and the reception light emitted from the coupling end face of the optical fiber Fi (6) into the optical fiber Fi (6). A receiving optical waveguide SDi (5-2) that guides to the corresponding light receiving portion Si and receives light, and N (= 1) transmitting optical waveguides HDi (5-1) are transmitting optical waveguide layers (7 ) And N (= 1) receiving optical waveguides SDi (5-2) are receiving light. The optical waveguide layer for transmission (7) and the optical waveguide layer for reception (8) are formed in the waveguide layer (8) and laminated in the thickness direction so as to be integrated as a plate-shaped optical waveguide element (5). In addition, the transmission optical waveguide HDi (5-1) and the reception optical waveguide SDi (5-2) are laminated close to each other on the fiber coaxial side at the coupling end surface portion on the optical fiber Fi (6) side, and the light emitting unit On the Hi side and the light receiving part Si side, they are formed apart by a distance between the light emitting part Hi and the light receiving part Si in a direction perpendicular to the thickness direction of the optical waveguide element (5).
[0034]
Further, the optical fiber Fi (i = 1) to be optically coupled is a multimode optical fiber (Claim 2), and the light emitting portion Hi is a light emitting surface of a surface emitting laser (Claim 3). The part Si is mounted on the same substrate 10 (claim 4). Number of light emitting units, light receiving units, and optical fibers: N is N = 1 (Claim 5).
[0035]
Since the optical fiber 6 is a “multi-mode optical fiber having a large core diameter”, when the laminated optical waveguide layer 5 is “input / output coupled” to the optical fiber, light input / output efficiently shifted in the stacking direction is performed. In addition, the relative positional accuracy between the optical waveguide element 5 and the coupling end face of the optical fiber 6 can be relaxed.
[0036]
As the “multimode optical fiber” having a large core diameter, a plastic optical fiber (POF), a hard plastic clad fiber (HPCF), or the like can be suitably used.
[0037]
The “surface emitting laser” used as the light-emitting element 1 is suitable for “high-speed transmission” because it can modulate light faster than the conventional edge-emitting semiconductor laser, and the light emitting pattern is circular and the beam divergence angle is moderate. Since it is small, the coupling efficiency to the transmission optical waveguide 5-1 can be increased, and the positional accuracy for coupling can be reduced.
[0038]
The light emitting element 1 and the light receiving element 2 do not necessarily have the same semiconductor substrate, and the light emitting element 1 generates heat. However, by mounting the light emitting element 1 and the light receiving element 2 apart from each other as in the above embodiment, Electrical crosstalk can be effectively suppressed.
[0039]
FIG. 2 shows another embodiment.
2A is a plan view, and FIG. 2B is a side view.
In FIG. 2A, reference numeral 1A indicates "a light emitting section array in which a plurality of (four in the illustrated example) light emitting sections are integrally arrayed in the vertical direction of the figure". As the light emitting section array 1A, an end surface light emitting type or surface light emitting type semiconductor laser or LED or the like is individually arrayed, or a plurality of semiconductor laser light emitting sources are monolithically integrated like a semiconductor laser array. Can be used.
[0040]
In this embodiment, a “surface emitting laser (surface emitting semiconductor laser) integrally arrayed” is used as the light emitting section array 1A. In the light emitting section array 1A, each light emitting section is individually driven according to a transmission signal by the drive circuit 2A, and laser light is emitted from each “light emitting section (light emitting end face)”.
[0041]
The light receiving section array indicated by reference numeral 3A in FIG. 2A is formed by integrally arraying a plurality of (four in this example) light emitting elements, and the light receiving surface that is the “light receiving section” of each light receiving element. When light is received, an “electric signal corresponding to the amount of light received” is generated. This electric signal is amplified for each signal of each light receiving section by the amplifier circuit 4A.
As shown in FIG. 2A, the light emitting unit array 1A, the drive circuit 2A, the light receiving unit array 3A, and the amplifier circuit 4A are mounted on the same support substrate 10A.
[0042]
In FIG. 2, reference numeral 5A denotes an “optical waveguide element”, and reference numeral 6A denotes an array of a plurality (four in this embodiment) of optical fibers 6-1, 6-2, 6-3, 6-4. Optical fiber array ". Each of the optical fibers 6-1 to 6-4 is also a “multimode optical fiber” in this embodiment.
[0043]
The optical waveguide element 5A is “plate-shaped”, and as shown in FIG. 5B, the transmission optical waveguide layer 7A and the reception optical waveguide layer 8A are laminated in the thickness direction and integrated.
[0044]
The plurality of transmission optical waveguides 5-11 to 5-14 are formed in the transmission optical waveguide layer 7A, and the reception optical waveguide layers 5-21 to 5-24 are formed in the reception optical waveguide layer 8A.
As shown in FIGS. 2A and 2B, the transmission optical waveguides 5-11 to 5-14 and the corresponding reception optical waveguides 5-21 to 5-24 are arranged on the optical fiber array 6A side. The optical fiber coupling end face portions are laminated close to each other on the fiber coaxial line, and the end portions of the respective waveguides are opposed to the coupling end faces of the corresponding optical fibers 6-1 to 6-4. Yes.
[0045]
Further, the transmitting optical waveguides 5-11 to 5-14 and the receiving optical waveguides 5-21 to 5-24 are orthogonal to the thickness direction of the plate-shaped optical waveguide element 5A on the light emitting unit array 1A and the light receiving unit array 2A side. 2 (a vertical direction of FIG. 2A, a direction orthogonal to the drawing of FIG. 2B) is separated by “the interval between each light emitting part of the light emitting part array 1A and each light receiving part of the light receiving part array 2A”. It is formed as follows.
[0046]
Since the transmission optical waveguide layer 7A and the reception optical waveguide layer 8A are laminated in the thickness direction, the transmission optical waveguides 5-11 to 5-14 and the reception optical waveguides 5-21 to 5-24 are: The corresponding light emitting unit array / light receiving unit array side (left side in FIG. 2) is also separated in the thickness direction for each corresponding pair, and the light emitting unit and light receiving unit of the light emitting unit array 1A are separated according to the separation amount in the thickness direction. The light receiving portion of the array 3A has a “step” in the thickness direction.
[0047]
When a “transmitting optical signal” is radiated from an arbitrary light emitting section of the light emitting section array 1A, the light signal is transmitted from the transmitting optical waveguides 5-11 to 5-14 formed in the optical waveguide element 5A. (The end on the light-emitting part side is close to and faces the light-emitting part) and enters the transmission optical waveguide and guides the transmission optical waveguide to the other end side. Waves are coupled into the optical fiber from the coupling end face of the optical fiber (corresponding to the transmission optical waveguide) coupled to the other end, and are coupled and transmitted through the optical fiber.
[0048]
When the “receiving optical signal” is transmitted from the right side to the left side of the optical fiber array 6A in an arbitrary optical fiber, the optical signal is transmitted from the coupling end surface of the optical fiber. Incident into the corresponding receiving optical waveguide, guided to the light receiving unit array 3A side, emitted from the end surface on the corresponding light receiving unit side, and incident on the light receiving unit in close proximity to the end surface to generate a light receiving signal Let This received light signal is amplified by the amplifier circuit 4A and becomes a received signal.
[0049]
In this way, “bidirectional transmission / reception is possible for each optical fiber”, and the optical fibers are arrayed so that a plurality of optical fibers (four channels in this embodiment) can be transmitted in parallel. In parallel large-capacity communication using a light emitting unit array, a light receiving unit array, and an optical fiber array, bidirectional optical communication can be realized with a simple configuration.
[0050]
Further, the transmitting optical waveguides 5-11 to 5-14 and the receiving optical waveguides 5-21 to 5-24 are orthogonal to the thickness direction of the optical waveguide element 5A on the light emitting unit array 1A / light receiving unit array 3A side. Since they can be separated from each other in the direction, it is possible to effectively prevent optical crosstalk in which an optical signal radiated from the light emitting unit enters the light receiving unit.
[0051]
That is, the bidirectional optical communication module whose embodiment is shown in FIG. 2 corresponds to N (= 4) light emitting portions Hi (each light emitting surface of the light emitting portion array 1A) and 1: 1 to the light emitting portions. The light receiving portion Si (each light receiving surface of the light receiving portion array 3A), the light emitting portion Hi corresponding to each other, the pair of the light receiving portions Si and the coupling end face of the optical fiber Fi (6-1 to 6-4) corresponding to 1: 1. , A transmission optical waveguide HDi (5-11 to 5-14) for guiding the transmission light radiated from the light emitting part Hi and entering the optical fiber Fi (6-1 to 6-4) from the coupling end face, and the optical fiber Receiving optical waveguide SDi (5-) for guiding the received light emitted from the coupling end face of Fi (6-1 to 6-4) to the light receiving portion Si corresponding to optical fiber Fi (6-1 to 6-4). 21 to 5-24), and N (= 4) optical waveguides for transmission HDi (5-11 to 5-5) 14) is formed in the same transmission optical waveguide layer (7A), and N (= 4) reception optical waveguides SDi are formed in the same reception optical waveguide layer (8A). The layer (7A) and the receiving optical waveguide layer (8A) are laminated in the thickness direction and integrated as a plate-shaped optical waveguide element (5A), and the transmitting optical waveguide HDi (5-11-5-5) 14) and the receiving optical waveguide SDi (5-21 to 5-24) are laminated close to each other on the optical fiber Fi (6-1 to 6-4) side at the coupling end face, and the light emitting portion Hi. On the side and the light receiving part Si side, the distance between the light emitting part Hi and the light receiving part Si is formed so as to be separated in a direction perpendicular to the thickness direction of the optical waveguide element (5A).
[0052]
The optical fibers Fi (6-1 to 6-4) to be optically coupled are multimode optical fibers (Claim 2), the light emitting portion Hi is a light emitting surface of a surface emitting laser (Claim 3), and emits light. The part Hi and the light receiving part Si are mounted on the same substrate 10A (Claim 4), and the number of light emitting parts, light receiving parts, and optical fibers: N is N = 4 (≧ 2) (Claim 6), N The light emitting portions are integrally arrayed (Claim 7), and the N light receiving portions are also integrally arrayed (Claim 8).
[0053]
Since the optical fibers 6-1 to 6-4 are “multimode optical fibers having a large core diameter”, when input / output coupling to the optical fiber is performed with the stacked optical waveguide layer 5A, input / output of light shifted in the stacking direction. Can be performed efficiently, and the relative positional accuracy between the optical waveguide element 5A and each coupling end face of the optical fiber array 6A can be relaxed.
[0054]
As the “multimode optical fiber” having a large core diameter, a plastic optical fiber (POF), a hard plastic clad fiber (HPCF), or the like can be suitably used.
[0055]
The “surface emitting semiconductor laser” used in the light emitting section array 1A in an array arrangement is suitable for “high speed transmission” because it can modulate light faster than the conventional edge emitting semiconductor laser, and the light emitting pattern is circular. Since the beam divergence angle is also reasonably small, the coupling efficiency to the transmission optical waveguides 5-11 to 5-14 can be increased, and the positional accuracy for coupling can be reduced.
[0056]
The semiconductor substrate is not necessarily the same in the light emitting unit array 1A and the light receiving unit array 2A, and each light emitting unit in the light emitting unit array generates heat. However, as in the embodiment shown in FIG. 2, the light emitting unit array 1A and the light receiving unit array By mounting away from 2A, electrical crosstalk can be effectively suppressed.
[0057]
The intervals between the optical fibers in the optical fiber array 6A, the intervals between the light emitting portions in the light emitting portion array, and the intervals between the light receiving portions in the light receiving portion array are not necessarily the same and may be different. In particular, since a plastic optical fiber having a large core diameter has a core diameter of about 0.7 mm, the distance between the optical fibers in the optical fiber array 6A is close to 1 mm.
[0058]
Since the light emitting unit array and the light receiving unit array are semiconductor elements, the smaller the chip, the lower the cost. Therefore, the distance between the light emitting part and the light receiving part in the light emitting part array or the light receiving part array may be smaller than the distance between the optical fibers in the optical fiber array 6A.
[0059]
An example of a method for manufacturing the optical waveguide device of the present invention will be described taking the case of the optical waveguide device 5A shown in FIG. 2 as an example.
In FIG. 3A, reference numerals 70 and 80 denote transparent substrates.
As shown in FIG. 3A, the “core portion to be the transmission optical waveguide (reference numerals 5-11 to 5-14 in FIG. 2)” on the transparent substrate 70 has a higher refractive index than the transparent substrate 70. Depending on the material, the transmission optical waveguide portions 511 to 514 are formed as the transmission optical waveguide substrate 700.
[0060]
Similarly, as shown in FIG. 3 (a), N core parts having a refractive index higher than that of the transparent substrate 80 are placed on the other transparent substrate 80 to receive optical waveguide parts 521 to 524 (in FIG. 2). The receiving optical waveguide substrate 800 is formed as a portion to be the receiving optical waveguides 5-21 to 5-24.
Each core part can be formed by photolithography, “drawing with a core material ejection head” or the like.
As shown in FIG. 3B, the formed core portions (transmitting optical waveguide portions 511 to 514 and receiving optical waveguide portions 521 to 524) are irradiated with “UV light” to solidify the core portions. . The solidification of each core part may be performed by “substrate heating”.
[0061]
Next, as shown in FIG. 3C, the sides where the core portions are formed face each other, and the core portions on the transparent substrates are spaced apart from each other (in the vertical direction of FIG. 3C). The adhesive 110 having a refractive index substantially equal to those of the transparent substrates 70 and 80 is filled between the transparent substrates 70 and 70, and the adhesive 110 is solidified by UV light irradiation (or substrate heating). (At this time, the refractive index of the solidified adhesive is substantially equal to the refractive index of the transparent substrates 70 and 80, and the optical waveguide portions 511 to 514 and 521 to 524 are formed by the substrates 70 and 80 and the solidified adhesive layer 110. The role of the clad portion surrounding the core portion is provided), and the optical waveguide element 5A described with reference to FIG. 2 is obtained (FIG. 3D).
[0062]
In the completed optical waveguide element 5A, the optical waveguide portions 511 to 514 become the transmission optical waveguides 5-11 to 5-14 (in FIG. 3D, the upper portion including this portion is shown in FIG. ), And the optical waveguide portions 521 to 524 are the reception optical waveguides 5-21 to 5-24 (the lower portion including this portion in FIG. 2 (b)).
[0063]
FIG. 4 shows the state of the “end face portion on the optical fiber array side” of the optical waveguide element 5A. Each optical fiber (shown in the figure) of the optical fiber array 6A is compared with the array of optical waveguide layers for transmission (upper part in the figure) and the array of optical waveguides for reception (lower part in the figure) laminated in the thickness direction. 6-1 to 6-4 are set so as to enter the corresponding optical waveguide portions for transmission / reception. With this arrangement, “transmission light coupling” from each transmission optical waveguide to each optical fiber and “reception light coupling” from each optical fiber to each reception optical waveguide are performed by one optical fiber. Can do.
[0064]
FIG. 5 shows another embodiment of the optical waveguide device.
The optical waveguide element of this form is functionally the same as that shown in FIG. 3D (in order to avoid complication, the same reference numerals as those in FIG. Using.).
[0065]
The clad layers 70B and 80B are applied to the substrates 70A and 80A by a spin coat method, a dipping coat method, a roll coat method, or the like, and solidified by UV light irradiation or heating to form the clad layers 70B and 80B. On the cladding layers 70B and 80B, the core portions 514 and 521 of the optical waveguide portion are formed in the same manner as in the method of FIG. Thereafter, the core portions are opposed to each other and are adhered by the adhesive layer 110 as in the case of FIG.
[0066]
The clad layers 70B and 80B have substantially the same refractive index as that of the adhesive layer 110. The core portions 514 and 521 are surrounded by the clad layers 70B and 80B and the adhesive layer 110 so as to serve as a clad of the waveguide. The substrates 70A and 80A do not necessarily need to be transparent, and a semiconductor substrate such as Si, an “opaque substrate” such as a ceramic substrate or a printed substrate can also be used.
[0067]
FIG. 6 is a diagram showing another embodiment of the optical waveguide device (in order to avoid complications, components that are not likely to be confused are given the same reference numerals as in FIG. 3).
[0068]
In this optical waveguide element 5A, a light guide film 200 includes a waveguide portion 514 formed by a core portion formed on one transparent substrate 70, a waveguide portion 521 formed by a core portion formed on the other transparent substrate 80, and the like. (Claim 10).
[0069]
In the optical waveguide device shown in FIGS. 4 and 5, if the transmitting optical waveguide and the receiving optical waveguide are separated by an appropriate distance in the stacking direction, the transmitted light leaks into the receiving optical waveguide due to scattering in the waveguide. There is almost no cross talk between sending and receiving, but there is no possibility of cross talk between sending and receiving when the optical waveguide element is thinned and both optical waveguides approach each other. do not do.
[0070]
Even in such a case, the light shielding film 200 is interposed between the transmission optical waveguide and the reception optical waveguide as shown in FIG. 6 to prevent leakage of transmission light from the transmission side to the reception side. be able to. The light shielding film 200 has various methods such as a method of adhering upper and lower optical waveguide layers with a “dye-containing adhesive in which a light-absorbing dye is mixed with an adhesive”, and a method of forming a metal thin film between the upper and lower optical waveguides. It can be formed by a method.
[0071]
In the above, the manufacturing method in the case where a plurality of waveguides are arranged in an array has been described. However, as can be easily understood, the same method as described above can be used when there is a single optical waveguide in each optical waveguide layer. Can be manufactured.
[0072]
【The invention's effect】
As described above, according to the present invention, a novel bidirectional optical communication module, optical waveguide element, and bidirectional optical communication module device can be realized.
The bidirectional optical communication module of the present invention is capable of basic transmission / reception with a single optical fiber, has a simple configuration for bidirectional transmission, downsizing the module, and reducing and configuring the number of fibers. Costs can be reduced by reducing the number of parts, and optical and electrical crosstalk can be effectively prevented.
Moreover, it is possible to perform transmission / reception in parallel using a plurality of optical fibers.
[0073]
The optical waveguide device of the present invention is easy to manufacture and can be formed small and thin.
Further, as in the invention described in claim 4, by mounting one or more light emitting portions Hi and light receiving portions Si on the same substrate, conversion from an electric signal to an optical signal and conversion from an optical signal to an electric signal can be performed. It becomes possible on the same substrate, and it is easy to achieve electrical matching with an electric circuit (LSI) for bidirectional communication, and the module configuration is simplified and the size can be reduced by mounting on the same substrate.
[0074]
By combining such a bidirectional optical communication module with an optical fiber, it is possible to realize a bidirectional optical communication module device that enables good bidirectional optical communication.
[Brief description of the drawings]
FIG. 1 is a diagram for explaining one embodiment of a bidirectional optical communication module and a bidirectional optical communication module apparatus.
FIG. 2 is a diagram for explaining another embodiment of the bidirectional optical communication module and the bidirectional optical communication module device.
FIG. 3 is a drawing for explaining an example of a method for manufacturing an optical waveguide device.
4 is a diagram showing a state of the optical waveguide element of FIG. 3 on the optical fiber array side.
FIG. 5 is a diagram for explaining another embodiment of the optical waveguide device.
FIG. 6 is a diagram for explaining another embodiment of the optical waveguide device.
[Explanation of symbols]
1 Light emitting element
3 Light receiving element
5 Optical waveguide device
5-1 Optical waveguide for transmission
5-2 Optical waveguide for reception
6 Optical fiber

Claims (14)

N (≧ 1) light emitting portions Hi (i = 1 to N);
The light receiving part Si corresponding to the light emitting part 1: 1,
The transmission light emitted from the light emitting part Hi (i = 1 to N) is guided to the coupling end face of the optical fiber Fi corresponding to the pair of the light emitting part Hi and the light receiving part Si corresponding to each other, and from the coupling end face An optical waveguide for transmission HDi that enters the optical fiber Fi;
A receiving optical waveguide SDi that guides received light emitted from the coupling end surface of the optical fiber Fi to the light receiving portion Si corresponding to the optical fiber Fi and receives the received light;
N transmission optical waveguides HDi are formed in the same transmission optical waveguide layer, and N reception optical waveguides SDi are formed in the same reception optical waveguide layer. The receiving optical waveguide layer is laminated in the thickness direction and integrated as a plate-shaped optical waveguide element, and
The transmission optical waveguide HDi and the reception optical waveguide SDi (i = 1 to N) are laminated close to each other on the fiber coaxial side at the coupling end surface portion on the optical fiber Fi side, and on the light emitting unit Hi side and the light receiving unit Si side. The bidirectional optical communication module, wherein the bidirectional optical communication module is formed so as to be separated by a distance between the light emitting portion Hi and the light receiving portion Si in a direction orthogonal to the thickness direction of the optical waveguide element. The bidirectional optical communication module according to claim 1,
A bidirectional optical communication module, wherein an optical fiber Fi (i = 1 to N) to be optically coupled is a multimode optical fiber. The bidirectional optical communication module according to claim 1 or 2,
A bidirectional optical communication module, wherein the light emitting portion Hi (1 = 1 to N) is a light emitting surface of a surface emitting laser. The bidirectional optical communication module according to any one of claims 1 to 3,
The bidirectional optical communication module, wherein the light emitting part Hi and the light receiving part Si (i = 1 to N) are mounted on the same substrate. The bidirectional optical communication module according to any one of claims 1 to 4,
A bidirectional optical communication module, wherein N = 1. The bidirectional optical communication module according to any one of claims 1 to 4,
A bidirectional optical communication module, wherein N ≧ 2. The bidirectional optical communication module according to claim 6, wherein
A bidirectional optical communication module, wherein N light emitting units are integrally arrayed. The bidirectional optical communication module according to claim 6 or 7,
A bidirectional optical communication module, wherein N light receiving portions are integrally arrayed. The bidirectional optical communication module according to any one of claims 1 to 8,
The optical waveguide element
A transmission optical waveguide substrate in which N core portions having a refractive index higher than that of the transparent substrate are formed on the transparent substrate as transmission optical waveguide portions,
On another transparent substrate, a receiving optical waveguide substrate in which N core portions having a refractive index higher than that of the transparent substrate are formed as receiving optical waveguide portions,
Bidirectional light characterized in that each of the core portions is opposed to each other, and each transparent substrate is filled and integrated with an adhesive having a refractive index substantially equal to that of each transparent substrate. Communication module. The bidirectional optical communication module according to claim 9, wherein
In the optical waveguide element, a waveguide portion formed by a core portion formed on one transparent substrate and a waveguide portion formed by a core portion formed on the other transparent substrate are opposed to each other through a light shielding film. Bidirectional optical communication module. An optical waveguide device used in the bidirectional optical communication module according to claim 9 or 10. The optical waveguide device according to claim 11, wherein
An optical waveguide element, wherein N = 1. The optical waveguide device according to claim 11, wherein
An optical waveguide element, wherein N ≧ 2. A bidirectional optical communication module device comprising a combination of the bidirectional optical communication module according to claim 1 and N optical fibers.

Images