JP2011112771A - Optical transmission and reception module - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To obtain an optical transmission and reception module in which a wavelength multiplexing/demultiplexing filter is mounted readily and accurately, in a state with an accurate mounting angle being maintained. <P>SOLUTION: The optical transmission and reception module includes an optical transmission module which transmits a first optical signal along a first axial line; an optical reception module which receives a second optical signal along a second axial line that crosses the first axial line; the wavelength multiplexing/demultiplexing filter which is provided at a position at which the first axial line and the second axial line cross each other and transmits the first optical signal and reflects the second optical signal; a fiber ferrule and an optical fiber which are provided on the first axial line and transmits the first optical signal and the second optical signal; and a housing 2 which houses and holds those components. The optical transmission and reception module, further, includes a filter holder 6 which is suitable for a hole 20 formed on the housing and holds the wavelength multiplexing/demultiplexing filter, and the filter holder 6 includes a positioning part 6c, having a notched shape which is suitable for the hole part 20c of the hole 20 and a press-fitting part 6a which is press-fitted in the hole part 20a of the hole 20. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

The present invention relates to an optical transceiver module used for single-fiber bidirectional optical communication.

Conventionally, as this type of single-fiber bidirectional optical module, an optical path hole is provided in a housing that holds an optical signal transmitting unit, an optical signal receiving unit, and an optical transmission component, and upstream and downstream optical signals are provided in the optical path hole. Is inserted and fixed (for example, see Patent Document 1).

JP 2009-37174 A

However, in such an optical transmission / reception module, since the multiplexing / demultiplexing characteristics of the optical filter depend on its own mounting angle, it is important to mount it with high accuracy. Therefore, in the case of inserting and fixing an optical filter in the optical path hole of the housing as in the above-mentioned Patent Document 1, it is difficult to mount the optical filter in a state in which the mounting angle is maintained with high accuracy, and it takes a lot of time. There was a problem of requiring labor.

The present invention has been made to solve such problems, and an object of the present invention is to obtain an optical transceiver module to which a wavelength multiplexing / demultiplexing filter can be easily attached with high accuracy.

An optical transceiver module according to the present invention receives a second optical signal along a second axis that intersects the first axis, and a transmitter that transmits the first optical signal along the first axis. A receiver, a wavelength multiplexing / demultiplexing filter provided at a position where the first axis and the second axis intersect, transmitting the first optical signal and reflecting the second optical signal, and the first axis And an optical signal transmission unit for transmitting the first optical signal and the second optical signal, and housing the above transmission unit, reception unit, wavelength multiplexing / demultiplexing filter, and optical signal transmission unit And a filter holder that holds the wavelength multiplexing / demultiplexing filter, and the filter holder includes a notch-shaped positioning portion that fits into the hole. And a press-fitting portion that is press-fitted and fixed in the hole.

According to the present invention, by holding the wavelength multiplexing / demultiplexing filter and using the filter holder having the positioning portion and the press-fitting portion, the filter holder can be press-fitted and fixed with respect to the housing. An optical transmission / reception module to which the multiplexing / demultiplexing filter can be easily attached with high accuracy can be obtained.

1 is a configuration development diagram showing a configuration of an optical transceiver module according to Embodiment 1 of the present invention. It is a front view of the filter holder shown in FIG. It is a left view of the filter holder shown in FIG. It is a right view of the filter holder shown in FIG. It is a top view of the filter holder shown in FIG. It is a bottom view of the filter holder shown in FIG. FIG. 3 is a diagram illustrating a method for incorporating the filter holder according to the first embodiment. It is a front view of the filter holding | maintenance part shown in FIG. It is another front view of the filter holder shown in FIG. FIG. 10 is a diagram illustrating a method for incorporating a filter holder according to the second embodiment.

Embodiment 1 FIG.
An optical transmission / reception module according to the present invention includes, for example, a subscriber-side optical line termination unit (hereinafter referred to as ONU) or a station-side optical line termination unit (hereinafter referred to as ONU) in an optical access system GE-PON (Gigabit Ethernet Passive Optical Network). Used for OLT (Optical Line Terminal). In this embodiment, an optical transmission / reception module mounted on an ONU will be described with reference to FIGS.

In FIG. 1, an optical transmission module 3 that converts an electrical signal of upstream digital data into an optical signal in the 1310 nm band and transmits the optical signal along the first axis 1 </ b> A is provided in a housing 2 of the optical transceiver module 1. And a first optical receiving module 4 that is provided on a second axis 1B orthogonal to the first axis 1A and receives a downstream optical signal in the 1490 nm band and converts it into an electrical signal of digital data, that is, a receiving unit And a first optical receiving module 4 on a third axis 1C parallel to the second axis 1B, and receiving a 1490 nm band downstream optical signal and receiving an electrical signal for digital video The second optical receiving module 5 to be converted, i.e., the receiving unit, is mounted and held by adhesion, welding, or the like.

Further, the housing 2 is provided with a hole 20 so as to include a position where the first axis 1A and the second axis 1B intersect and a position where the first axis 1A and the third axis 1B intersect. A filter holder 6 that holds the wavelength multiplexing / demultiplexing filters 11 and 12 that reflects light in a specific wavelength band and transmits light in other wavelength bands is press-fitted and fixed to 20.

A condenser lens 7 that condenses the optical signal transmitted from the optical transmitter module 3 is provided between the filter holder 6 and the optical transmitter module 3. On one axis 1A, a fiber ferrule 8 and an optical fiber 9, that is, an optical transmission unit, whose end surfaces are cut obliquely (about 8 degrees from a plane perpendicular to the axis) are provided. The fiber ferrule 8 is fixed in the vicinity of the side surface of the filter holder 6, and a single mode optical fiber 9 is held at the axial center thereof, and is connected to an optical fiber network outside the ONU via a connector 10.

As shown in FIGS. 2 to 6, the filter holder 6 is fixed to both ends of the filter holding portion 6b holding the wavelength multiplexing / demultiplexing filters 11 and 12 so that the center is substantially coincided with the filter holding portion 6b. The disk-shaped press-fit portion 6 a and a cylindrical positioning portion 6 c having a notch shape such as a D-cut fit along a hole 20 provided in the housing 2 are configured. The press-fitting portion 6a has a disk shape having an inclined side surface with a small diameter on the side facing the filter holding portion 6b, and the thickness in the press-fitting direction is thinner than the cylindrical length of the positioning portion 6c.

As shown in FIG. 7, the hole 20 provided in the housing 2 has a cylindrical hole portion 20a having a diameter slightly smaller than the press-fit portion 6a in order from the inlet side, and a concentric circular shape that is slightly smaller than the hole portion 20a. The hole portion 20b and a hole portion 20c having a shape cut into a D-cut shape so as to be fitted to the positioning portion 6c of the filter holder 6 are configured. The diameter of the hole 20a is smaller toward the side closer to the hole 20b, and a step is formed at the boundary between the hole 20a and the hole 20b.
The positioning portion 6c is not limited to having a D-cut surface as long as it can prevent horizontal displacement and rotational displacement of the filter holder 6, but may be a cylindrical positioning portion 6d having an I-cut surface as shown in FIG. There may be. Alternatively, the hole 20c may be cut out to form a protrusion on the positioning portion 6c.

Here, the shape of the filter holding part 6b will be described in detail. As shown in FIG. 8, the filter holding part 6b has a shape in which two triangular prisms are cut out from one side surface 60 of the rectangular parallelepiped along the press-fitting direction. The cuts are made at about 45 degrees from both sides of the side surface 60 toward the center.

An intersection of the first axis 1A and the second axis 1B is located on an inclined surface 61 formed by cutting the filter holding portion 6b, and the first axis 1A and the second axis 1B are located on another inclined surface 62. An intersection of two axes 1C is located. In order to guide the optical signal to the surface 61 and the surface 62, cylindrical optical paths 63a to 63c are formed in the filter holding portion 6b along the first axis 1A, and the optical signal in the 1490 nm band is reflected on the surface 61. A wavelength multiplexing / demultiplexing filter 11 for reflecting the optical signal in the 1550 nm band is attached to the surface 62. Further, the end surface of the fiber ferrule 8 is in contact with the side surface 66 of the optical path 63c outside the filter holding portion 6b. In addition, in order to guide the optical signal from the optical transmission module 3 to the housing 2 portion between the optical transmission module 3 and the side surface 65 of the filter holding portion 6b, an optical path 2a (illustrated) along the first axis 1A. Not) is formed.

The filter holding unit 6b is provided with a wavelength band limiting filter 32 that transmits only light having a wavelength in the vicinity of 1490 nm on the side surface 60 between the wavelength multiplexing / demultiplexing filter 11 and the first optical receiving module 4, A wavelength band limiting filter 33 that transmits only light having a wavelength near 1550 nm is attached to a side surface 64 between the wave filter 12 and the second optical receiver module 5. Further, an optical path 63d that guides the optical signal in the 1550 nm band reflected by the wavelength multiplexing / demultiplexing filter 12 from the surface 62 to the surface 64 is formed along the third axis 1C.

In the case 2 between the optical receiver module 4 and the side surface 60 of the filter holding portion 6b, light is guided along the second axis 1B to guide the optical signal to the optical transmitter module 4 in the same manner as the optical path 2a. A passage 2b (not shown) is provided along the third axis 1C to guide the optical signal to the optical transmission module 5 in the housing 2 portion between the optical receiving module 5 and the surface 65 of the filter holding portion 6b. Each passage 2c (not shown) is formed.

The upstream optical signal in the 1310 nm band output from the optical transmission module 3 passes through the optical path 2a and is collected by the condenser lens 7, and then the optical path 63a and wavelength multiplexing / demultiplexing along the first axis 1A. It passes through the filter 11, the optical path 63 b, the wavelength multiplexing / demultiplexing filter 12, and the optical path 63 c, and reaches the end face of the fiber ferrule 8. The optical signal taken into the optical fiber 9 at the end face of the fiber ferrule 8 is transmitted to the optical fiber network outside the ONU through the connector 10.

On the contrary, the optical signal in the downward 1490 nm band and the optical signal in the 1550 nm band transmitted from the external optical fiber network to the optical fiber 9 through the connector 10 are transmitted from the end face of the fiber ferrule 8 to the optical path 63c. Then, the light enters the wavelength multiplexing / demultiplexing filter 12. The optical signal having a wavelength of 1550 nm is reflected by the wavelength multiplexing / demultiplexing filter 12, passes through the wavelength band limiting filter 14 through the optical path 63 d, and is received by the second optical reception module 5. On the other hand, an optical signal having a wavelength of 1490 nm is transmitted through the wavelength multiplexing / demultiplexing filter 12, passes through the optical path 6b, reflected by the wavelength multiplexing / demultiplexing filter 11, and then transmitted through the wavelength band limiting filter 13 to obtain the first light. Received by the receiving module 4.

In this way, the wavelength band limiting filters 13 and 14 that transmit only the optical signals in the vicinity of the wavelength band received by the optical receiving modules 4 and 5 in addition to the wavelength multiplexing and demultiplexing filters 11 and 12 are added to the filter holder 6. By providing on the second axis 1B or the third axis 1C, which is the path of light reflected by the filters 11, 12, light of different wavelengths that cause crosstalk is removed, and desired wavelength band limiting performance And the reception performance of the optical receiver modules 4 and 5 can be improved.

Next, a method for incorporating the filter holder 6 into the housing 2 will be described.
As shown in FIG. 7, the positioning portion 6c of the filter holder 6 is inserted at a position that naturally follows the D-cut shape of the hole 20c provided in the housing 2, and the positioning portion 6c is the bottom of the hole 20c. The press-fit portion 6a is pressurized in the depth direction of the hole when it is fitted and pivotally supported in a state that does not cause horizontal displacement or rotational displacement. The press-fit portion 6a of the filter holder 6 spreads the hole portion 6a along the side surface inclination, and is press-fitted and fixed to the housing 2 when the lower end portion comes into contact with the step at the boundary between the hole portion 20a and the hole portion 20b.

In this way, the filter holder 6 inserts the positioning portion 6c into the hole portion 20c of the housing 2 and fits it, and the press-fit portion 6a is inserted into the hole portion 20a while being pivotally supported and the positions in the horizontal direction and the rotational direction are determined. Therefore, the wavelength multiplexing / demultiplexing filters 11 and 12 can be easily and accurately attached to the housing 2 by preventing the filter holder 6 from being fixed to the housing 2 in an unstable posture. Further, since the filter holder 6 also holds the wavelength band limiting filters 13 and 14, the relative angle between the wavelength multiplexing / demultiplexing filters 11 and 12 and the wavelength band limiting filters 13 and 14 is uniquely determined. 14 can also be attached with high accuracy.

Note that, here, a case where one optical transmission module and two optical reception modules are mounted is shown. However, even if two or more optical transmission modules and three or more optical reception modules are mounted, This can be dealt with by appropriately increasing the number of multiplexing / demultiplexing filters and wavelength band limiting filters. In this case, a plurality of filter holders 6 are connected and incorporated in the housing 2 as an integrated object.
Further, not only the optical transceiver module 1 mounted on the ONU but also the optical transceiver module mounted on the OLT, the same effect can be obtained by using the filter holder 6 having the same shape.

According to this embodiment, the filter holder 6 that is fitted in the hole 20 formed in the housing 2 and holds the wavelength multiplexing / demultiplexing filters 11, 12 is provided. A positioning part 6c having a D-cut notch shape that has a filter holding part 6b that holds 11 and 12 and that is fitted to the hole part 20c of the hole 20 at both ends of the filter holding part 6b. The filter holder 6 is tilted and fixed to the housing 2 in an unstable posture by having the press-fit portion 6a that is press-fitted and fixed to the hole portion 20a in a state where the portion 6c is fitted and supported by the hole portion 20b. Therefore, it is possible to obtain the optical transmission / reception module 1 in which the wavelength multiplexing / demultiplexing filters 11 and 12 can be easily attached to the housing 2 with high accuracy.

In addition to the wavelength multiplexing / demultiplexing filters 11 and 12, the filter holder 6 includes wavelength band limiting filters 13 and 14 that transmit only optical signals in the vicinity of the wavelength band received by the optical receiving modules 4 and 5 and wavelength multiplexing / demultiplexing. By holding on the second axis 1B or the third axis 1C, which is the path of light reflected by the filters 11, 12, between the wavelength multiplexing / demultiplexing filters 11, 12 and the wavelength band limiting filters 13, 14 The relative angle can be maintained with high accuracy, light having different wavelengths causing crosstalk can be removed, desired wavelength band limiting performance can be secured, and the receiving performance of the optical receiving modules 4 and 5 can be improved.

Embodiment 2. FIG.
The optical transceiver module 1 according to the present embodiment will be described with reference to FIG.
The configuration of the optical transmission module 1 is the same as that of the first embodiment, and the shapes of the filter holder 600 and the hole 200 are different. As shown in FIG. 10, the filter holder 600 according to the present embodiment is provided on both sides of a cylindrical positioning portion 6 f having a notch shape such as a D-cut, on the side surface having a small diameter on the side facing the positioning portion 6 f. The disk-shaped press-fit portion 6e having an inclination and a filter holding portion 6f that is provided at a position where the center of the press-fit portion 6e substantially coincides and holds the wavelength multiplexing / demultiplexing filters 11 and 12 are configured.

The hole 200 provided in the housing 2 is formed in a D-cut shape in order from the inlet side so as to be fitted to the cylindrical hole 20e having a slightly smaller diameter than the press-fit portion 6e and the positioning portion 6f of the filter holder 6. The hole 20f has a hollow shape and a cylindrical hole 20g that is deeper than the hole 20e in which the filter holding portion 6b is stored and has a smaller diameter than the hole 20f. The diameter of the hole 20e is smaller toward the side closer to the hole 20f, and a step is formed at the boundary between the hole 20e and the hole 20f.

As in the first embodiment, the positioning portion 6f is not limited to the one having the D-cut surface as long as it can prevent the horizontal displacement and the rotation displacement of the filter holder 600, and has a cylindrical shape having the I-cut surface. Alternatively, the hole 20f may be a notch shape, and a protrusion that fits into the notch shape may be formed in the positioning portion 6f.
Since the operation of the optical transceiver module 1 is the same as that of the first embodiment, the description thereof is omitted.

Next, a method for incorporating the filter holder 600 into the housing 2 will be described.
As shown in FIG. 10, the filter holding part 6b and the positioning part 6f of the filter holder 600 are inserted into the holes 20g and 20f provided in the housing 2, and the positioning part 6f is fitted into the hole 20f and pivotally supported. The press-fit portion 6e is pressurized in the depth direction of the hole when no horizontal displacement or rotational displacement occurs. The press-fitting portion 6e of the filter holder 600 spreads the hole 6e along the inclination of the side surface, and is fixed to the housing 2 when the lower end is in contact with the step at the boundary between the hole 20e and the hole 20f.

As described above, the filter holder 600 inserts the filter holding portion 6b and the positioning portion 6f into the holes 20g and 20f of the housing 2, and the positioning portion 6f is pivotally supported by being fitted into the hole 20f. Since the press-fit portion 6e is press-fitted and fixed in the hole portion 20e in a state where the direction position is determined, the filter holder 600 is prevented from being fixed to the housing 2 in an unstable posture, and the wavelength multiplexing / demultiplexing filter 11, 12 can be easily attached to the housing 2 with high accuracy. Further, since the filter holder 600 also holds the wavelength band limiting filters 13 and 14, the relative angle between the wavelength multiplexing / demultiplexing filters 11 and 12 and the wavelength band limiting filters 13 and 14 is uniquely determined, and the wavelength band limiting filter 13, 14 can also be attached with high accuracy.

The filter holder 600 according to this embodiment can also be applied to an optical transmission / reception module on which two or more optical transmission modules and three or more optical reception modules are mounted. Further, the present invention can be applied not only to an ONU but also to an optical transceiver module mounted on an OLT.

According to this embodiment, the housing 2 has the hole 200 that houses the filter holder 600, and the filter holder 600 that holds the wavelength multiplexing / demultiplexing filters 11, 12 is fitted into the hole 20 f of the hole 20. A filter holding portion 6b holding the wavelength multiplexing / demultiplexing filters 11 and 12 at both ends of the positioning portion 6f having a D-cut notch shape, and the positioning portion 6f are fitted and supported by the hole 20f. In this state, the filter holder 6 is prevented from being inclined and fixed to the housing 2 in an unstable posture, and the wavelength multiplexing / demultiplexing filters 11 and 12 are provided. It is possible to easily obtain the optical transceiver module 1 that can be easily attached to the housing 2 with high accuracy.

In addition to the wavelength multiplexing / demultiplexing filters 11, 12, the filter holder 600 includes wavelength band limiting filters 13, 14 that transmit only optical signals in the vicinity of the wavelength band received by the optical receiving modules 4, 5. By holding on the second axis 1B or the third axis 1C, which is the path of light reflected by the filters 11, 12, between the wavelength multiplexing / demultiplexing filters 11, 12 and the wavelength band limiting filters 13, 14 The relative angle can be maintained with high accuracy, light having different wavelengths causing crosstalk can be removed, desired wavelength band limiting performance can be secured, and the receiving performance of the optical receiving modules 4 and 5 can be improved.

DESCRIPTION OF SYMBOLS 1 Optical transmission / reception module 2 Housing | casing 3 Optical transmission module 4, 5 Optical reception module 6, 600 Filter holder 6a, 6e Press-fit part 6b, Filter holding part 6c, 6d, 6f Positioning part 8 Fiber ferrule 9 Optical fiber 20, 200 Hole 11 , 12 Wavelength multiplexing / demultiplexing filters 13, 14 Wavelength band limiting filter 1A First axis 1B Second axis 1C Third axis

Claims (4)

A transmitter for transmitting the first optical signal along the first axis;
A receiver that receives a second optical signal along a second axis that intersects the first axis;
A wavelength multiplexing / demultiplexing filter that is provided at a position where the first axis and the second axis intersect, transmits the first optical signal, and reflects the second optical signal;
An optical signal transmission unit provided on the first axis and configured to transmit the first optical signal and the second optical signal;
In the optical transmission / reception module having the transmission unit, the reception unit, the wavelength multiplexing / demultiplexing filter, and a housing for storing and holding the optical signal transmission unit,
The filter holder is fitted into a hole formed in the housing and holds the wavelength multiplexing / demultiplexing filter. The filter holder is a notch-shaped positioning portion that fits into the hole, and is press-fitted into the hole. And a press-fitting portion. The filter holder is
A filter holding unit for holding the wavelength multiplexing / demultiplexing filter;
The optical transceiver module according to claim 1, wherein the positioning portion and the press-fitting portion are positioned at both ends of the filter holding portion. The filter holder is
A filter holding unit for holding the wavelength multiplexing / demultiplexing filter;
The optical transceiver module according to claim 1, wherein the press-fitting part and the filter holding part are located at both ends of the positioning part. The filter holder is provided on the second axis, and holds a wavelength band limiting filter that transmits only light having a wavelength in the vicinity of the second optical signal reflected by the wavelength multiplexing / demultiplexing filter. The optical transmission / reception module according to any one of claims 1 to 3.

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