JP2004191460A - Optical transmission and reception module - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an optical transmission and reception module which does not require an optical waveguide requiring a complicated manufacturing process and is small in size and low in price. <P>SOLUTION: On an Si substrate 6, a recessed groove 9 whose flank slants at 45° to the optical axis of an optical fiber 8 and a lens 7 is formed and in the groove for fixation, a WDM filter 4 is fixed so that a filter film 4a is perpendicular to the surface of the Si substrate (the horizontal surface of the groove for filter fixation) and also projects upward from the top surface of the Si substrate. On the Si substrate, a PD 1, an LD 2, an M-PD 3, and a preamplifier 5 are positioned and mounted by using an alignment marker 10. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to an optical transceiver module used for optical fiber communication and the like.
[0002]
[Prior art]
In recent years, attention has been paid to optical fiber communication that can transmit high-speed, large-capacity information with low loss in place of a metallic cable, and there is an increasing demand for higher functionality as well as lower cost and higher speed of optical devices. As an example, the development of an optical communication system that realizes upstream and downstream optical bidirectional transmission at different wavelengths using one optical fiber has been promoted, and the optical module of this system includes a light emitting element, A technology for integrating a light receiving element with functional components for wavelength separation and multiplexing is required.
[0003]
Hereinafter, a typical example of a conventional optical transmitting / receiving module will be described. Conventionally, a structure in which an optical waveguide and a WDM filter are combined to separate a signal having a reception wavelength λ1 from a transmission wavelength λ2 is generally used. FIG. 7 shows a conventional structure of a WDM (wavelength multiplexing) optical bidirectional module using an optical waveguide described in Patent Document 1 below. Optical waveguides 102a, 102b and 102c are formed on the Si substrate 103. After high-precision two-dimensional adjustment, one end of the optical waveguide 102a can be optically coupled with light emitted from the light emitting element 105, and one end of the optical waveguide 102b can be optically coupled with light incident on the light receiving element 106. The light emitting element 105 (and the monitoring light receiving element 104) and the light receiving element 106 are mounted. The position adjustment of the light emitting element 105 and the light receiving element 106 is generally performed using an alignment marker 108 formed on the Si substrate 103 with high precision in advance.
[0004]
[Patent Document 1]
JP-A-11-68705 (FIG. 1, abstract)
[0005]
The output light of the wavelength λ2 of the light emitting element 105 is reflected by the WDM filter 107 and then introduced into the optical fiber 101 through the optical waveguide 102c. Here, the core of the optical fiber 101 and the optical waveguide 102c are arranged so that they can be optically coupled. As an arrangement method, a method of processing a V-shaped groove on the Si substrate 103 with high precision at the position of the optical waveguide 102c and fixing the optical fiber 101 along the V groove is general. . On the other hand, the optical signal of wavelength λ1 transmitted from the optical fiber 101 passes through the optical waveguide 102c, the WDM filter 107, and the optical waveguide 102b, and is received by the light receiving element 106. The light receiving element 106 has a structure that can receive light by entering light from the side of the chip.
[0006]
[Problems to be solved by the invention]
The above conventional example has the following problems.
The conventional optical module requires a complicated manufacturing process for forming the V-groove and the alignment marker 108 for positioning and the optical waveguides 102a, 102b, and 102c on the Si substrate 103 with high accuracy, and has an optical waveguide. The size of the Si substrate 103 has increased, making it difficult to reduce the cost of the Si substrate 103 itself, and to reduce the size of the module. In addition, the mounting accuracy of the light receiving element 106 and the light emitting element 105 is required to be high from micron to submicron, the mounting apparatus is very expensive, the mounting time is long, and the number of manufacturing steps is increased.
[0007]
SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned problems of the prior art, and to provide a small and inexpensive optical transceiver module which does not require an optical waveguide requiring a complicated manufacturing process.
[0008]
[Means for Solving the Problems]
In order to achieve the above object, the invention described in claim 1 is:
A substrate formed with a groove having a side surface inclined at a predetermined angle with respect to the optical axis of the optical fiber and the lens,
With a wavelength selective filter or a half mirror arranged on the side surface of the groove,
One of the light emitting element and the light receiving element is arranged on the transmitted light side of the wavelength selective filter or the half mirror on the substrate, and the other is arranged on the reflected light side.
With this configuration, the manufacturing process is complicated, and an expensive optical waveguide is not required, and a small-sized WDM optical transceiver module can be realized. In addition, since the optical coupling with the optical fiber is performed using the lens, it is not necessary to perform high-precision processing on the substrate and to mount the light-receiving element and the light-emitting element with high precision. Further, the position and the angle of the filter can be fixed accurately and reliably.
[0009]
The invention according to claim 2 includes a substrate having a flat surface,
A wavelength-selective filter or a half mirror disposed at a predetermined angle to the optical axis of the optical fiber and the lens on the substrate,
One of the light emitting element and the light receiving element is arranged on the transmitted light side of the wavelength selective filter or the half mirror on the substrate, and the other is arranged on the reflected light side.
With this configuration, the manufacturing process is complicated, and an expensive optical waveguide is not required, and a small-sized WDM optical transceiver module can be realized. In addition, since the optical coupling with the optical fiber is performed using the lens, it is not necessary to perform high-precision processing on the substrate and to mount the light-receiving element and the light-emitting element with high precision.
[0010]
The invention described in claim 3 is the optical transceiver module according to claim 1 or 2,
A preamplifier for amplifying an output of the light receiving element is mounted on the substrate.
With this configuration, since the light receiving element and the preamplifier can be mounted close to each other, the influence of electric crosstalk or the like is small and the receiving characteristics are improved.
[0011]
The invention described in claim 4 is the optical transceiver module according to any one of claims 1 to 3,
The substrate is mounted on a can package stem, and optical coupling to the optical fiber is performed using a can package lens.
With this configuration, the conventional technology and general-purpose components can be used, and highly accurate optical coupling is possible, and at the same time, an inexpensive optical transceiver module can be realized.
[0012]
According to a fifth aspect of the present invention, in the optical transmitting / receiving module according to any one of the first to fourth aspects,
The wavelength-selective filter or the half mirror is a polyhedral glass block, and a filter film or a half mirror is formed on at least one surface of the glass block.
With this configuration, it is possible to easily manufacture and mount the filter or the half mirror.
[0013]
According to a sixth aspect of the present invention, in the optical transceiver module according to the fifth aspect,
The glass block is a rectangular parallelepiped, and the filter film or the half mirror is formed on a side surface.
With this configuration, manufacture and mounting of the filter or the half mirror can be made easier, and the optical transceiver module can be realized at lower cost.
[0014]
According to a seventh aspect of the present invention, in the optical transceiver module according to the fifth or sixth aspect,
The position of the glass block is adjusted using a marker on the substrate, and then the glass block is fixed.
With this configuration, it is not necessary to form a high-precision groove for positioning the filter on the substrate.
[0015]
The invention described in claim 8 is the optical transmission / reception module according to any one of claims 2 to 7,
The light-emitting element of the light-emitting element is disposed at a position distant from a mounting surface of the substrate so as to face the wavelength-selective filter or the half mirror.
With this configuration, light from the light emitting element can be efficiently incident on the filter or the half mirror without requiring complicated processing such as a groove on the substrate.
[0016]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
<First embodiment>
1 to 3 are configuration diagrams of an optical transceiver module according to the first embodiment of the present invention. On the silicon (Si) substrate 6, a filter fixing groove (hereinafter referred to as a filter fixing groove) 9 whose side surface is inclined by 45 ° with respect to the optical axis of the optical fiber 8 and the lens 7 is formed. A light receiving element (PD) 1, a light emitting element (LD) 2, a monitoring light receiving element (M-PD) 3, and a preamplifier 5 are positioned and mounted using an alignment marker 10.
[0017]
The WDM filter 4 is fixed to the filter fixing groove 9 such that the filter film 4a is perpendicular to the surface of the Si substrate 6 (the horizontal bottom surface of the filter fixing groove 9). In this case, the WDM filter 4 is fixed such that the surface 4b opposite to the filter film 4a is along the vertical side surface of the filter fixing groove 9, and the filter film 4a is projected above the upper surface of the Si substrate 6. By doing so, the angle of incidence of light on the WDM filter 4 can be accurately defined. Here, the WDM filter 4 has a structure in which a multilayer film filter is formed on one surface of a rectangular parallelepiped glass substrate and is easily mass-produced.
[0018]
The PD 1 and the LD 2 are arranged on opposite sides of the WDM filter 4. As shown in FIG. 1, the PD 1 is arranged on the optical axis after the light from the optical fiber 8 has passed through the WDM filter 4, and the LD 2 enters the optical fiber 8 after the emitted light is reflected by the WDM filter 4. Arrange so that you can. Optical coupling is achieved by disposing a lens 7 between the LD 2 and PD 1 and the optical fiber 8. Since it is not a direct connection with the optical fiber 8 as in the conventional example, high-precision V-groove processing and high-precision submicron mounting precision of the LD2 and PD1 are unnecessary. In the present embodiment, the Si substrate 6 is used. However, since high-precision processing or the like is not required, a ceramic substrate such as alumina or AlN can be used.
[0019]
FIG. 2 is a diagram of the Si substrate 6 viewed from the left direction A on the optical fiber 8 side, and FIG. 3 is a diagram of the Si substrate 6 viewed from the front diagonally right direction B. As shown in FIGS. 2 and 3, the light-emitting portion on the lower surface of the rectangular parallelepiped LD2 and the light-entering portions on the lower surfaces of the PD1 and the M-PD3 are mounted on the Si substrate 6 side. A groove 6a is provided on the Si substrate 6 on the outgoing light side of the LD 2 so that the groove 6a is not blocked by the light.
[0020]
FIG. 4 shows a modularized configuration of the assembly 15 configured as described above. After the Si substrate 6 is mounted on the can package stem 13, it is hermetically sealed with the lens cap 12 having the lens 7. Further, the lens 7 is optically coupled to the optical fiber 8. By using the lens cap 12 and the can package stem 13 which are general components of the package, low cost can be realized. The present invention can be applied not only to the wavelength division method using the WDM filter 4, but also to a time division method using a half mirror instead of the WDM filter 4, and the LD2 (and M-PD3) And the arrangement position of PD1 may be reversed.
[0021]
<Second embodiment>
FIGS. 5 and 6 are configuration diagrams of an optical transceiver module according to the second embodiment of the present invention. The configuration is the same as that of the first embodiment except that the filter fixing groove 9 is not provided in the Si substrate 6, and the PD1, LD2, M-PD3, preamplifier 5, and WDM filter 4 are mounted on the upper surface of the Si substrate 6. I do. All components 1 to 5 are mounted based on the alignment marker 10. Thereby, the component mounting process can be simplified, and at the same time, the groove processing is not required in the Si substrate 6, and the component price can be reduced. As in the first embodiment, a ceramic substrate such as alumina or AlN can be used instead of the Si substrate 6.
[0022]
FIG. 6 is a perspective view of the Si substrate 6 shown in FIG. In the second embodiment, since the WDM filter 4 is fixed on the same surface as the LD 2, the WDM filter 4 is mounted so that the LD light emitting unit 2 a above the rectangular parallelepiped LD 2 faces the surface 14 on which the filter film 4 a is formed. Thereby, it is possible to prevent the LD light from being partially blocked by the Si substrate 6.
[0023]
【The invention's effect】
As described above, according to the first aspect of the present invention, a compact wavelength multiplexing optical transmission / reception module can be realized without a complicated manufacturing process and an expensive optical waveguide. In addition, since the optical coupling with the optical fiber is performed using the lens, it is not necessary to perform high-precision processing on the substrate and to mount the light-receiving element and the light-emitting element with high precision. Further, the position and the angle of the filter can be fixed accurately and reliably.
According to the second aspect of the present invention, a compact wavelength multiplexing optical transmission / reception module can be realized without an expensive optical waveguide having a complicated manufacturing process. In addition, since the optical coupling with the optical fiber is performed using the lens, it is not necessary to perform high-precision processing on the substrate and to mount the light-receiving element and the light-emitting element with high precision.
[0024]
According to the third aspect of the present invention, since the light receiving element and the preamplifier can be mounted close to each other, the influence of electric crosstalk or the like is small and the receiving characteristics are improved.
According to the fourth aspect of the present invention, the conventional technology and general-purpose components can be used, and high-precision optical coupling can be performed, and at the same time, an inexpensive optical transceiver module can be realized.
According to the invention described in claim 5, it is possible to easily manufacture and mount the filter or the half mirror.
According to the invention described in claim 6, the manufacture and mounting of the filter or the half mirror can be made easier, and the optical transceiver module can be realized at lower cost.
According to the seventh aspect of the present invention, it is not necessary to form a high-precision groove for positioning the filter on the substrate.
According to the eighth aspect of the present invention, the light of the light emitting element can be efficiently incident on the filter or the half mirror without requiring complicated processing such as a groove on the substrate.
[Brief description of the drawings]
FIG. 1 is a schematic configuration diagram of a first embodiment of an optical transceiver module according to the present invention; FIG. 2 is a side view of a Si substrate viewed from a left direction A on the optical fiber side in FIG. 1 FIG. FIG. 4 is a side view of the Si substrate viewed from the oblique right direction B of the front in FIG. 4. FIG. 4 is a schematic view of a package according to the first embodiment of the present invention. FIG. 5 is a second embodiment of the optical transceiver module of the present invention. FIG. 6 is a perspective view of an optical transceiver module according to a second embodiment of the present invention viewed from a direction C of a Si substrate and the like according to a second embodiment of the present invention. FIG. 7 is a schematic configuration of a conventional optical transceiver module. Perspective view showing [Description of reference numerals]
1 Light receiving element for reception (PD)
2 Light emitting element (LD)
3 Monitor light receiving element (M-PD)
Reference Signs List 4 WDM filter 4a Filter film 4b Filter film opposite side 5 Preamplifier 6 Silicon (Si) substrate 6a Groove 7 Lens 8 Optical fiber 9 Filter fixing groove 10 Alignment marker 11 LD light emitting unit 12 Lens cap 13 Can package stem 14 Filter film Forming surface

Claims (8)

A substrate formed with a groove having a side surface inclined at a predetermined angle with respect to the optical axis of the optical fiber and the lens,
With a wavelength selective filter or a half mirror arranged on the side surface of the groove,
An optical transmitting and receiving module in which one of a light emitting element and a light receiving element is arranged on the transmitted light side of the wavelength selective filter or the half mirror on the substrate, and the other is arranged on the reflected light side. A substrate with a flat surface,
A wavelength-selective filter or a half mirror disposed at a predetermined angle to the optical axis of the optical fiber and the lens on the substrate,
An optical transmitting and receiving module in which one of a light emitting element and a light receiving element is arranged on the transmitted light side of the wavelength selective filter or the half mirror on the substrate, and the other is arranged on the reflected light side. The optical transceiver module according to claim 1 or 2, further comprising a preamplifier for amplifying an output of the light receiving element on the substrate. The optical transceiver module according to any one of claims 1 to 3, wherein the substrate is mounted on a can package stem, and configured to perform optical coupling to the optical fiber using a can package lens. . 5. The optical transceiver according to claim 1, wherein the wavelength selective filter or the half mirror is a polyhedral glass block, and a filter film or a half mirror is formed on at least one surface of the glass block. 6. module. The optical transceiver module according to claim 5, wherein the glass block is a rectangular parallelepiped, and the filter film or the half mirror is formed on a side surface. The optical transceiver module according to claim 5, wherein the glass block is fixed after performing position adjustment using a marker on the substrate. The light according to any one of claims 2 to 7, wherein the light emitting unit of the light emitting element is disposed at a position away from a mounting surface of the substrate so as to face the wavelength selective filter or the half mirror. Transmit / receive module.

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