JP3683385B2 - Optical transceiver module - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an optical transceiver module for coupling a light emitting element and a light receiving element to an optical fiber through which a plurality of transmission light and reception light having different wavelengths are transmitted.
[0002]
[Prior art]
FIG. 5 is a sectional view showing a conventional example of this type of optical transceiver module, which is disclosed in Japanese Patent Laid-Open No. 3-164703. As shown in the figure, a plurality of through holes are accurately formed in the side wall of the metal case 100, and the light emitting element 101, the collimator lens 102, the common port lens 103, the light receiving element 104, and the collimator are formed in these through holes. An optical member such as a glass ring 106 that supports the lens 105 is attached. A glass block 107 is fixed inside the metal case 100, and a multilayer dielectric filter 108 and a reflection mirror 109 are formed at opposite corners of the glass block 107. The light emitting element 101, the collimating lens 102, the multilayer dielectric filter 108, and the common port lens 103 are on the first axis, and the optical fiber 110 is disposed on the first axis. The optical fiber 110 is fixed to the side wall of the metal case 100 by a holder 111, and a spacer prism 112 is inserted in the gap between the multilayer dielectric filter 108 and the end face of the collimating lens 102. The light receiving element 104, the collimating lens 105, and the reflecting mirror 109 are arranged on a second axis parallel to the first axis, and a spacer prism 113 is also inserted in the gap between the end face of the collimating lens 105 and the glass block 107. ing.
[0003]
In the optical transceiver module configured as described above, the transmission light having the wavelength λ1 emitted from the light emitting element 101 is transmitted through the collimating lens 102, the spacer prism 112, and the multilayer dielectric filter 108, and then the glass block 107 and the common port. It enters the end face of the optical fiber 110 through the lens 103. On the other hand, the received light of wavelength λ2 emitted from the end face of the optical fiber 110 passes through the common port lens 103 and the glass block 107, is reflected by the multilayer dielectric filter 108, and further passes through the glass block 107. The light is reflected by the reflection mirror 109, passes through the glass block 107, the spacer prism 113, and the collimator lens 105 and enters the light receiving surface of the light receiving element 104.
[0004]
[Problems to be solved by the invention]
By the way, when assembling such an optical transceiver module, in general, after the light emitting element 101 is attached to the metal case 100, the optical axis of the optical member for transmission is aligned and the optical member on the optical fiber 110 side is made of metal. A method is employed in which the optical member of the light receiving element 104 is attached to the metal case 100 by attaching the optical member to the case 100 and then aligning the optical axis of the receiving optical member.
[0005]
However, in the conventional optical transceiver module described above, the light emitting element 101 and the light receiving element 104 are respectively attached to the inside of a pair of through holes formed on one end surface of the metal case 100. It was difficult to form, and this was a major factor that hindered miniaturization of the optical transceiver module. In particular, as a means for fixing the light emitting element 101 and the light receiving element 104, when the most general method of welding flange portions provided in the elements 101 and 104 is employed, a space in which a jig for welding is to be arranged is arranged. Must be secured around the through-hole, and accordingly, the interval between the two through-holes needs to be set larger accordingly, and the above problem becomes significant. In addition, since the optical axis of the receiving optical member is aligned based on the light emitting element 101, high accuracy is required for the mounting reference surface of the through hole corresponding to the light receiving element 104, but the inner bottom surface of the through hole ( It is difficult to process the mounting reference surface) with high accuracy, and there is another problem that the accuracy of optical axis adjustment is lowered.
[0006]
[Means for Solving the Problems]
In the present invention, a mounting hole serving as a mounting reference surface for the light emitting element is formed on one end surface of the housing block, and the one end surface of the housing block is used as a mounting reference surface for the light receiving device. With this configuration, when the light receiving element is mounted, the light emitting element mounted inside the mounting hole does not get in the way, so the light emitting element and the light receiving element can be arranged close to each other. Miniaturization is possible. Further, since the reference mounting surface of the light receiving element is formed on one end surface of the housing block, the mounting reference surface can be processed with high accuracy by cutting or the like.
[0007]
DETAILED DESCRIPTION OF THE INVENTION
In the optical transceiver module of the present invention, a light emitting element that emits transmission light, a first lens that collimates the transmission light emitted from the light emitting element, and a demultiplexing that transmits light collimated by the first lens. A filter and a second lens that collects light transmitted through the branching filter at the end face of the optical fiber are accommodated coaxially along a first axis in one housing block, and A reflecting member that reflects the received light that is emitted from the end face, collimated by the second lens, and reflected by the demultiplexing filter; a third lens that collects the light reflected by the reflecting member; and A light receiving element that receives light collected by the third lens is coaxially accommodated along a second axis parallel to the first axis in the housing block, and the housing block The mounting holes flange portion of the light emitting element on one end face is accommodated and formed, it was fixed flange portion of the light receiving element to the housing block the one end surface as a mounting reference surface.
[0008]
【Example】
An embodiment will be described with reference to the drawings. FIG. 1 is a sectional view of an optical transceiver module according to an embodiment of the present invention, FIG. 2 is a sectional view of a housing block provided in the optical transceiver module, and FIG. FIG. 4 is an exploded perspective view of the optical transceiver module, and FIG. 4 is an external view of the optical transceiver module.
[0009]
As shown in FIGS. 1 to 3, the optical transceiver module according to the present embodiment has one housing block 20, and supports the LD 6 and the lens 7 described in the conventional example with respect to the housing block 20. The lens holder 8, the demultiplexing filter 5, the lens holder 14 that supports the lens 13 on the transmission path side, and the optical fiber 12 are attached coaxially. Further, a reflection mirror 15 for receiving light, a lens holder 11 that supports the lens 10, and the PD 9 are coaxially attached to the housing block 20 in parallel with the optical axis.
[0010]
As shown in detail in FIG. 2, the housing block 20 has an opening 21 for placing the lens holder 8, an opening 22 for placing the main body portion of the LD 6, and a mounting hole for attaching the flange portion of the LD 6. 23 and an opening 24 for the optical path are formed continuously. The inner bottom surface 23a of the mounting hole 23 serves as a mounting reference surface for the LD 6, and the LD 6 is welded to the housing block 20 with its flange portion being abutted against the inner bottom surface 23a of the mounting hole 23. As a result, the entire flange portion of the LD 6 is fitted into the mounting hole 23, and only the lead portion protrudes from the side surface 31 of the housing block 20. The housing block 20 is provided with a mounting surface 25 for mounting the demultiplexing filter 5 at an angle of 45 ° with respect to the optical axis and a lens holder 14 coaxially with the light emitting side openings 21, 22, 24. The optical fiber 12 is attached to the side surface 28 of the housing block 20. Furthermore, the housing block 20 has an opening 29 for disposing the lens holder 11, an opening 30 for disposing the main body of the PD 9, and the reflecting mirror 15 in parallel with the light-emitting side openings 21, 22, 24. Is formed at an angle of 45 ° with respect to the optical axis. The side surface 31 of the housing block 20 serves as an attachment reference surface for the PD 9, and the PD 9 is welded to the housing block 20 with the flange portion being abutted against the side surface 31. Accordingly, the PD 9 is attached to the housing block 20 such that the flange portion and the lead portion protrude from the side surface 31, and the LD 6 is attached to the inside of the housing block 20 by the flange portion of the PD 9 from the PD 9. Front portions perpendicular to the mounting surface 25 of the demultiplexing filter 5 and the mounting surface 32 of the reflecting mirror 15 are largely open, and notches 25a and 32a corresponding to these open portions are formed in the housing block 20. . The housing block 20 is formed with a screw hole 33 and an engaging groove 34. The screw hole 33 is a screw (not shown) for fixing the optical transmission / reception module to the chassis or printed circuit board of the electronic device. It is an insertion hole, and the engagement groove 34 is for preventing the optical transmission / reception module from rotating at the time of screwing.
[0011]
The housing block 20 having such a shape is formed by cutting, for example, a metal material such as stainless steel. However, since the side surface 31 serving as the attachment reference surface of the PD 9 is the outer surface of the housing block 20, There is nothing that obstructs the cutting blade used when cutting 31, and the mounting reference surface of the PD 9 can be processed easily and with high accuracy. It is also possible to manufacture the housing block 20 with a die such as die casting instead of cutting, and in this case as well, the die shape corresponding to the side surface 31 is simplified, so that the reference mounting surface of the PD 9 Can be processed easily and with high precision.
[0012]
When assembling the optical transceiver module configured as described above, first, after attaching the demultiplexing filter 5, the reflection mirror 15, and the lens holders 8, 11, 14 to predetermined positions of the housing block 20, The flange portion of the LD 6 is butted against the inner bottom surface 23a of the mounting hole 23 and welded. Next, the optical fiber 12 is temporarily fixed to the end face of the opening 27, and the transmitted light (wavelength λ1) of the LD 6 is incident on the end face of the optical fiber 12 through the lens 7, the demultiplexing filter 5, and the lens 13 with an accurate optical axis. After performing the optical axis adjustment as described above, the optical fiber 12 is fixed to the housing block 20 by welding or the like. Next, the main body of the PD 9 is inserted into the opening 30 of the housing block 20, and the received light (wavelength λ 2) emitted from the end face of the optical fiber 12 is the lens 13, the demultiplexing filter 5, the reflection mirror 15, and the lens 10. Then, the optical axis is adjusted so that it enters the light receiving surface of the PD 9 with an accurate optical axis, and then the flange portion of the PD 9 is welded to the housing block 20 with the side surface 31 as the attachment reference surface. Thereafter, a U-shaped cover 40 is attached to the housing block 20 to protect the notches 25a and 32a on the demultiplexing filter 5 side and the reflection mirror 15 side from dust. A tongue piece 41 is formed on the LD 40 side cover 40 at an angle at which the light reflected by the demultiplexing filter 5 does not return, and the light transmitted through the reflection mirror 15 does not return to the PD 9 side cover 40. The tongue piece 41 is formed at an angle. Finally, as shown in FIG. 4, a label 42 is wound around the cover 40, the cover 40 is fixed to the housing block 20, and a hole in the cover 40 formed by the tongue piece 41 is closed, thereby transmitting and receiving light. The assembly work of the module is completed.
[0013]
【The invention's effect】
The present invention is implemented in the form as described above, and has the effects described below.
[0014]
A light emitting element that emits transmission light; a first lens that collimates transmission light emitted from the light emitting element; a demultiplexing filter that transmits light collimated by the first lens; and the demultiplexing filter. A second lens that condenses the transmitted light at the end face of the optical fiber is accommodated coaxially along the first axis in one housing block, and is emitted from the end face of the optical fiber to the second lens. A reflecting member that reflects the received light reflected by the demultiplexing filter, a third lens that collects the light reflected by the reflecting member, and a light that is collected by the third lens. And a light receiving element that receives the received light coaxially along a second axis parallel to the first axis in the casing block, and a flange of the light emitting element is provided on one end surface of the casing block. If the flange portion of the light receiving element is fixed to the housing block using the one end face as an attachment reference surface, the light emission attached inside the mounting hole when the light receiving element is attached. Since the element does not get in the way, the light emitting element and the light receiving element can be arranged close to each other, and the housing block can be made smaller by that amount, and the mounting reference surface of the light receiving element is formed on one end surface of the housing block. Therefore, the attachment reference surface can be processed with high accuracy by cutting or the like.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view of an optical transceiver module according to an embodiment of the present invention.
FIG. 2 is a cross-sectional view of a housing block provided in the optical transceiver module.
FIG. 3 is an exploded perspective view of the optical transceiver module.
FIG. 4 is an external view of the optical transceiver module.
FIG. 5 is a cross-sectional view showing a conventional optical transceiver module.
[Explanation of symbols]
5 Demultiplexing filter 6 LD (Laser diode)
7, 10, 13 Lens 8, 11, 14 Lens holder 9 PD (photodiode)
12 Optical fiber 15 Reflecting mirror 20 Housing blocks 21, 22, 24, 26, 29, 30 Opening 23 Mounting hole 23a Inner bottom surface (reference mounting surface)
31 Side (reference mounting surface)

Claims (1)

A light emitting element that emits transmission light; a first lens that collimates transmission light emitted from the light emitting element; a demultiplexing filter that transmits light collimated by the first lens; and the demultiplexing filter. The second lens that collects the transmitted light at the end face of the optical fiber is coaxially accommodated along the first axis in one housing block, and
A reflecting member that reflects the received light that is emitted from the end face of the optical fiber, collimated by the second lens, and reflected by the branching filter; and a third member that collects the light reflected by the reflecting member. A lens and a light receiving element that receives light collected by the third lens are coaxially accommodated along a second axis parallel to the first axis in the housing block,
In addition, an attachment hole for accommodating the flange portion of the light emitting element is formed on one end surface of the housing block, and the flange portion of the light receiving element is fixed to the housing block with the one end surface as an attachment reference surface. An optical transceiver module is characterized.

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