JPH07181351A - Transmitting and receiving module for optical communication - Google Patents

Abstract

PURPOSE:To provide an optical communication with transmitting and receiving module which facilitates the positioning between a photoreceptor and a light emitting hole, and is easy to manufacture. CONSTITUTION:In a transmitting and receiving module which is for optical communication and formed by inserting a light receiving and transmitting device 1 including a photoreceptor 13 and a light emitting element 14 to a recessed part 22 formed on a receptacle 2, a light emitting hole having substantially a circular section for emitting a light to the photoreceptor 13 and a light incident hole for guiding the light from the light emitting element 14 are formed on the wall surface 25 forming the recessed part 22, and of the respective sides of the light receiving surface of the photoreceptor 13, the side laid along the direction of inserting the light transmitting and receiving device 1 is set longer than the other sides.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a transmission / reception module for optical communication used in an optical communication system such as a data link using a light as an information transmission medium and an optical LAN.

[0002]

2. Description of the Related Art In recent years, due to the demand for higher sophistication of telecommunication networks and higher speed of information communication processing, it is drawing attention to apply optical communication technology to various communication systems such as data buses / data links and optical LANs. . In such optical communication technology, for example, when a quartz optical fiber is used as a data link, it is necessary to pay attention to the following points. That is, since the diameter of the core of the optical fiber is several tens of microns, which is extremely fine, a highly accurate technique is required for optically coupling the light emitting element or the light receiving element with the optical fiber. As a technique for satisfying this, a light emitting module and a light receiving module as shown in FIG. 6 have been conventionally known. Here, the light emitting module and the light receiving module will be briefly described.

The light emitting module shown in FIG. 6 (a) is
It has a base body 101, a light emitting element 103 mounted on the upper surface of the base body 101 and provided with a ball lens 102, and a cover 104 including a cylindrical portion provided on the upper surface of the base body 101 so as to cover the light emitting element 103. . This cover 10
4 has a hollow interior as shown in the figure, a split sleeve 105 is formed in the cylindrical portion, and a SELFOC lens 106 is provided at a desired position. In addition, FIG.
The light receiving module shown in (b) includes a base 111, a light receiving element 112 mounted on the upper surface of the base 111, and various integrated circuits provided in an area 113 indicated by a chain line, and the light receiving elements 112 and And a cover 114 including a cylindrical portion provided on the upper surface of the base 111 so as to cover various integrated circuits. The inside of the cover 114 is hollow as shown in the drawing, and the split sleeve 11 is provided in the cylindrical portion.
5 is formed, and the SELFOC lens 116 is provided at a desired position.

However, in the prior art, the light emitting module and the light receiving module are separately formed in this way,
Furthermore, since the circuits for driving these are formed separately, the number of parts inevitably increases. Such an increase in the number of parts causes an increase in production cost, which causes a problem of a decrease in productivity. As a solution to this problem, a transceiver module for optical communication as shown in FIG. 7 is known.

The outline of the structure of the transceiver module for optical communication is as follows. That is, as shown in the figure, this optical communication transmitting / receiving module is one in which the optical transmitting / receiving apparatus 1 is inserted into the recess 22 formed in the receptacle 2. The optical transceiver 1 includes a substrate 11, and a light receiving element 18 and a light emitting element 14 provided on the substrate 11.
And a circuit 15 for driving the light receiving element 18 or the light emitting element 14 provided on the substrate 11, and the cover 12 provided on the substrate 11. Further, the receptacle 2 has a first cylindrical portion 21 in which an optical signal is introduced into the light receiving element 18 and the ball lens 25 is provided, and a second cylindrical portion (not shown) in which an optical signal from the light emitting element is derived. ) And have.

[0006]

However, the shape of the light irradiation opening of the first cylindrical portion 21 and the shape of the light incident opening of the second cylindrical portion are both circular, and the light emitting element 14 has the same shape. Since the light emitting portion and the light receiving surface 18a of the light receiving element 18 are also circular in shape, it is difficult to align them at the same time for alignment. That is, ideally from the viewpoint of improving the light receiving sensitivity of the light receiving element 18, all of the input light is applied to the light receiving surface 18a of the light receiving element 18, but the light receiving surface 18a of the light receiving element 18 also has the first cylindrical shape. Since the shape of the irradiation port of the portion 21 is circular, the light receiving sensitivity will be lowered if it is slightly misaligned. Further, in the above-described optical transmitter / receiver, since the light receiving element 18 and the light emitting element 14 are provided on the same substrate 11, it is difficult to align them at the same time.

To solve these problems, it is conceivable to increase the area of the light receiving surface 18a of the light receiving element 18, but if the light receiving surface 18a is made larger than necessary, the parasitic capacitance will increase. When the parasitic capacitance increases in this way, 1) the upper limit of the transmission speed is lowered and the light receiving sensitivity is lowered, and 2) the noise resistance is deteriorated.

Therefore, in order to solve the above problems, the present invention provides a transceiver module for optical communication in which the performance is kept constant and the alignment between the light receiving element and the light irradiation port is easy and the manufacturing is easy. The purpose is to provide.

[0009]

In order to solve the above problems, in a transceiver module for optical communication according to the present invention, a light receiving and transmitting device including a light receiving element and a light emitting element is provided in a recess provided in a receptacle. In the transceiver module for optical communication formed by inserting, on the wall surface forming the recess,
A light irradiation port having a substantially circular cross section for irradiating light to the light receiving element and a light incident port for introducing light from the light emitting element are formed, and the light receiving surface of the light receiving element is extended in the direction in which the optical transceiver is inserted. It is characterized by

The elongated portion of the light receiving surface is preferably formed in an arc shape centered on the light emitting element.

[0011]

According to the above structure, in the transceiver module for optical communication according to the present invention, the light-receiving surface of the light-receiving element provided in the light-transmitting / transmitting device is formed so as to extend in the direction in which the optical transceiver is inserted. Has been done. Therefore, even if a slight deviation occurs in the direction in which the optical transceiver is inserted, the light receiving area irradiated on the light receiving surface is always kept constant.

Further, if the elongated portion of the light receiving surface is formed in an arc shape centering on the light emitting element, the light receiving area can be more precisely kept constant.

[0013]

Embodiments of the present invention will be described below with reference to the accompanying drawings. The same elements are designated by the same reference numerals. In addition, the dimensional ratio of each portion in the drawings does not necessarily match the actual dimensional ratio, and the same applies to the area.

An optical communication transceiver module according to an embodiment of the present invention will be described with reference to FIG. As shown in FIG. 1, the transceiver module for optical communication includes an optical transceiver 1 and a receptacle 2.

As shown in FIGS. 1 and 2, the optical transmitter / receiver 1 comprises a ceramic substrate 11 and a transparent cover 12. A light receiving element 13, a light emitting element 14, and various integrated circuits for driving the light emitting element 14 and the light receiving element 13 are formed on the surface of the ceramic substrate 11. The light-receiving surface 13a of the light-receiving element 13 is formed in a rectangular shape or an arc shape having two sides facing each other as shown in the figure with the light-emitting element as the center. Further, the light receiving element 13 is provided on the ceramic substrate 11 so that the longitudinal direction of the light receiving surface 13a and the inserting direction of the optical transmitter-receiver 1 coincide with each other. In addition,
As the light receiving element 13, a photodiode is used here, but an avalanche photodiode or the like may be used instead. As the light emitting element 14, a light emitting diode is used here, but a semiconductor laser for optical communication can also be used. The various integrated circuits are formed in a region 15 surrounded by a chain line. A plurality of edge grips 16 are provided on one side of the ceramic substrate 11.

In the present embodiment, ceramic is used as the material of the substrate 11 from the viewpoint of the printability and thermal conductivity of the conductor, but as the material of the substrate 11, other than this, it is usually used as a substrate. There is no particular limitation as long as it is present, and for example, glass epoxy resin or the like can be used.

Further, as shown in FIG. 1, the receptacle 2 has a recess 22 into which the optical transmitter / receiver 1 is fitted,
A fiber accommodating portion 23 in which an optical fiber is set is formed. The wall 24 interposed between the recess 22 and the fiber accommodating portion 23 has a first tubular portion 21 having a light irradiation port for introducing an optical signal to the light receiving element 13 as shown in the figure.
And a second tubular portion having a light entrance for guiding an optical signal from the light emitting element 14. A ball lens 25 is provided inside the first tubular portion 21.

In manufacturing the transceiver module for optical communication, it is sufficient to fit the optical transceiver 1 into the recess 22 provided in the receptacle 2 and perform only the alignment on the side of the light emitting element 14, and the fine side on the side of the light receiving element 13. It is not necessary to perform alignment. That is, only the alignment between the light emitting element 14 and the second tubular portion is performed, and the fine alignment between the light receiving element 13 and the first tubular portion is not required. Therefore, the transceiver module for optical communication is provided. Is easy to manufacture. This is because the light receiving surface 13a of the light receiving element 13 is formed in a rectangular shape or in an arc shape with two sides facing each other centering on the light emitting element, and the longitudinal direction thereof coincides with the insertion direction of the optical transceiver 1. Therefore, a constant light receiving area is always secured without making fine adjustments in the vertical direction of the light receiving element 13. As shown in FIGS. 3A and 3B, the optical signal 3 introduced from the upper part of the first cylinder can secure a constant light receiving area regardless of which point of the light receiving surface 13a is fixed. is there.

Here, comparing the light-receiving surface of the conventional light-receiving element and the light-receiving surface of the light-receiving element according to this embodiment, the light-receiving areas of both are the same, as shown in FIG. 3 (c). As a result, the parasitic capacitances of the both are equal, and the two are also equal in terms of performance such as photosensitivity.

Therefore, also from this, it can be seen that in this embodiment, it is possible to provide the transceiver module for optical communication which is easy to manufacture while maintaining a constant performance.

As a result, since it is not necessary to increase the light receiving area more than necessary, the light receiving surface 13a can be easily aligned while keeping the light receiving sensitivity constant.

When ceramic is used from the viewpoint of printability and heat conductivity as in this embodiment, a protrusion called a burr is formed when the ceramic is cut off from the parent substrate. If such a burr remains on the substrate, it may cause a positional shift of the light receiving element when the optical transmitter / receiver 1 is inserted into the recess pull. The work of removing the burrs is very time-consuming and costly, and these are one of the causes of deteriorating the manufacturing efficiency of the optical communication transceiver module. However, as shown in FIG. 4, according to the present embodiment, even if there is such a burr 17, there is no drawback that the sensitivity is lowered due to the deviation in the insertion direction of the optical transmitter-receiver 1 as described above. . That is, if the burr 17 does not exist, the input light should be irradiated into the circular area 7a surrounded by the dotted line. However, since the optical transmitter / receiver 1 is entirely tilted by the burr 17, the circular area surrounded by the solid line is actually formed. It will be irradiated in 7b. However, in this embodiment, as shown in the drawing, even when the optical transmitter-receiver 1 is tilted, it is possible to secure the same light-receiving area as when the optical transmitter-receiver 1 is not tilted.

It is to be noted that the concept of the same substrate as used herein also includes a device in which the light receiving element and the light emitting element are formed on different substrates and these substrates are fixed and integrated by some method.

Next, a transceiver module for optical communication according to another embodiment of the present invention will be described.

As shown in FIG. 5, this optical communication transmitting / receiving module is largely different from the above-mentioned embodiment in that the light receiving element 13 and the light emitting element 14 are arranged along the direction in which the optical transmitting / receiving device 6 is inserted. There is a point. Even in such a case, if the longitudinal direction of the light-receiving surface 13a of the light-receiving element 13 is made to coincide with the insertion direction of the optical transmitter-receiver 6, the light-receiving element 13 can be aligned only by adjusting the position of the light-receiving element 13. The alignment can be performed by keeping it at.

In addition, although the arrangement of the edge grips is different from that of the above embodiment, it does not affect the present invention in this respect, and it goes without saying that it may be provided at any position. .

[0027]

As described in detail above, according to the present invention, the light-receiving area irradiated to the light-receiving surface is always kept constant even if there is some deviation in the direction in which the optical transceiver is inserted. Therefore, the light receiving element and the light irradiation port can be easily aligned without increasing the light receiving area more than necessary, the manufacturing of the transceiver module for optical communication is facilitated, and the light receiving sensitivity is kept constant. be able to.

[Brief description of drawings]

FIG. 1 is an assembled perspective view of a transceiver module for optical communication according to an embodiment of the present invention.

FIG. 2 is a perspective view showing an optical transceiver according to an embodiment of the present invention.

FIG. 3 is a conceptual diagram illustrating a light receiving surface of a light receiving element used in the optical transmitter / receiver according to the exemplary embodiment of the present invention.

FIG. 4 is an explanatory diagram of a transceiver module for optical communication according to an embodiment of the present invention.

FIG. 5 is a perspective view showing an optical transceiver according to another embodiment of the present invention.

FIG. 6 is a partial cross-sectional perspective view showing a light emitting module and a light receiving module according to a conventional technique.

FIG. 7 is a partial cross-sectional perspective view showing a transceiver module for optical communication according to a conventional technique.

[Explanation of symbols]

1, 6 ... Optical transmitter / receiver, 2 ... Receptacle, 11 ... Ceramic substrate, 12 ... Cover, 13 ... Light receiving element, 13a ...
Light receiving surface, 14 ... Light emitting element.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI technical display location H04B 10/04 10/06

Claims (2)

[Claims] 1. A transmission / reception module for optical communication, which is formed by inserting a light receiving / transmitting device including a light receiving element and a light emitting element into a recess provided in a receptacle, wherein a wall surface forming the recess has the light receiving element. A light irradiation port for irradiating light to the element and a light incident port for introducing light from the light emitting element are formed, and the light receiving surface of the light receiving element is extended in the direction in which the optical transceiver is inserted. A characteristic transceiver module for optical communication. 2. The transmission / reception module for optical communication according to claim 1, wherein the extended portion of the light receiving surface is formed in an arc shape centered on the light emitting element.