JP2012014025A - Optical transmitter receiver module - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an optical transmitter receiver module which is compact and has an excellent transmission efficiency.SOLUTION: The above object is achieved by an optical transmitter receiver module 1 including: a transmitting side substrate 2a having an element mounting surface 21a on which is provided with a light emitting element 4a, a transmitting side optical fiber positioning component 3a for containing a transmitting optical fiber 6a for transmitting light from the light emitting element 4a, and a transmitting semiconductor element 5a for electrically controlling the light emission of the light emitting element 4a; and a receiving side substrate 2b having an element mounting surface 21b on which is provided with a light receiving element 4b, a receiving side optical fiber positioning component 3b for containing a receiving optical fiber 6b for transmitting light to the light receiving element 4b, and a receiving semiconductor element 5b for amplifying an electrical signal from the light receiving element 4b. The element mounting surface 21a of the transmitting side substrate 2a and the element mounting surface 21b of the receiving side substrate 2b are disposed facing with each other.

Description

  The present invention relates to an optical transmission / reception module in optical parallel transmission that transmits and receives optical signals simultaneously to a plurality of transmission paths.

  In order to enable high-speed transmission of signals between electronic devices, an optical transmission / reception module is provided in the electronic devices, and signals between the electronic devices are transmitted via optical fibers. In general, an optical transceiver module used for such an application receives a VCSEL (Vertical Cavity Surface Emitting Laser) as a light emitting element, a driver IC for driving the VCSEL, a photodiode as a light receiving element, and an electric signal from the photodiode. And a transimpedance amplifier for amplification.

  As such an optical transceiver module, Patent Document 1 discloses an optical transceiver module in which an LD array composed of a plurality of light emitting elements and a PD array composed of a plurality of light receiving elements are independently fixed to a single printed circuit board. Yes.

JP-A-7-209557

  By the way, in the optical transceiver module, a relatively high current (about 10 mA) signal is output from the driver IC to drive the VCSEL, and a relatively low current (about 10 μA) signal is output from the photodiode to the transimpedance amplifier. Has been. For this reason, when an LD array (VCSEL) and a PD array (photodiode) are arranged on a common printed circuit board as in the optical transmission / reception module described in Patent Document 1, they interfere with each other because the distance between the members is short. There is a possibility that electrical crosstalk occurs, and a large noise may be mixed in a signal from the PD array (photodiode) to the transimpedance amplifier. Further, if the optical transceiver module is miniaturized, the distance between the wirings is shortened, so that there is a problem that noise is more likely to increase.

  In order to reduce noise, the present inventors provide the VCSEL 104a and the driver IC 105a on the transmission substrate 102a as shown in FIG. 3, and the photodiode 104b and the transimpedance amplifier 105b on the reception substrate 102b. Then, it was considered to laminate the transmission substrate 102a and the reception substrate 102b. With this configuration, as compared with the case where the optical transmitter and the optical receiver are arranged on the same printed board as described above, the width dimension of the optical transceiver module 101 (in the direction orthogonal to the longitudinal direction of the optical fiber). (Dimension) can be reduced. However, in the case of such a configuration, there is a problem that the optical transmission / reception module 101 becomes large in the longitudinal dimension of the optical fiber cable 106.

  That is, since the plurality of optical fibers 106a and 106b are bundled as one optical fiber cable 106 and extend to the outside of the optical transceiver module 101, the transmission substrate 102a and the reception substrate 102b are laminated to form the optical fibers 106a, 106b. When the distance between the optical fibers 106b increases, the optical fibers 106a and 106b need to be bent so as to close the distance between the optical fibers 106a and 106b in order to bundle them.

  However, when the optical fiber 106a has a steep bent portion 106a1 having a small radius of curvature, the transmission loss of the optical signal is increased at the bent portion 106a1 and the transmission efficiency is lowered. Therefore, when bending the optical fiber 106a, it is necessary to bend it gently so that the radius of curvature becomes large, and it is necessary to design the bent portion 106a1 to be long. Therefore, the optical transmission / reception module 101 becomes larger in the longitudinal direction of the optical fiber cable 106 as the bending portion 106a1 of the optical fiber 106 becomes longer.

  Accordingly, an object of the present invention is to provide an optical transceiver module that is compact and has good transmission efficiency.

According to the present invention, the following optical transceiver module is provided.
(1) A light-emitting element, a transmission-side optical fiber positioning component that houses a transmission optical fiber that transmits light from the light-emitting element, and a transmission semiconductor element that electrically controls light emission of the light-emitting element A transmission side substrate provided on the surface;
A light receiving element, a receiving-side optical fiber positioning component that houses a receiving optical fiber that transmits light to the light receiving element, and a receiving semiconductor element that amplifies an electric signal from the light receiving element are provided on the element mounting surface. An optical transceiver module comprising a receiving side substrate,
The element mounting surface of the transmission side substrate and the element mounting surface of the reception side substrate are arranged to face each other.

According to the optical transceiver module of the present invention, the light emitting element and the light receiving element are arranged on a single substrate because the element mounting surface of the transmission side substrate and the element mounting surface of the reception side substrate face each other. The size of the optical transceiver module can be reduced compared to the case where the optical transceiver module is made, and a compact optical transceiver module can be provided.
In addition, since the element mounting surface of the transmission side substrate and the element mounting surface of the reception side substrate are provided to face each other, the transmission side optical fiber positioning component and the reception side optical fiber are disposed between the transmission side substrate and the reception side substrate. Positioning components are arranged, and the distance between the transmission side optical fiber and the reception side optical fiber is reduced. Therefore, since these optical fiber bends can be combined into a single optical fiber cable without setting them large, it is possible to suppress transmission loss from occurring due to the bends of the optical fiber. Therefore, it is possible to provide an optical transceiver module that is compact and excellent in optical transmission efficiency.

It is a schematic diagram which shows the structural example between the electronic devices using the optical transmission / reception module which concerns on embodiment of this invention. It is a longitudinal cross-sectional view of the optical transmission / reception module which concerns on embodiment of this invention. It is a longitudinal cross-sectional view of the optical transmission / reception module which concerns on the comparative example of this invention.

  Hereinafter, an optical transceiver module according to an embodiment of the present invention will be described with reference to the drawings.

  As shown in FIG. 1, the optical transceiver module 1 according to the present embodiment is a device for connecting the optical fiber cable 6 to a first electronic device 20 and a second electronic device 30 such as a computer. For example, the electrical signal of the first electronic device 20 is converted into an optical signal by the optical transmission / reception module 1 attached to the first electronic device 20, transmitted into the optical fiber cable 6, and transmitted through the optical fiber cable 6. The optical signal is converted into an electric signal by the optical transmission / reception module 1 attached to the second electronic device 30, and is taken into the second electronic device 30. Similarly, the electrical signal of the second electronic device 30 is also transmitted through the optical transmission / reception module 1 attached to the second electronic device 30, the optical fiber cable 6, and the optical transmission / reception module 1 attached to the first electronic device 20. It is transmitted to the electronic device 20.

  Thus, the optical transceiver module 1 according to the present embodiment has both a function of transmitting an electrical signal as an optical signal and a function of receiving an optical signal as an electrical signal. Details of the optical transceiver module 1 will be described with reference to FIG.

  FIG. 2 is a longitudinal sectional view of the optical transceiver module 1 according to the embodiment of the present invention. The optical transceiver module 1 includes a transmission side substrate 2a, a reception side substrate 2b disposed so as to face the transmission side substrate 2a, and a metal housing 10 that covers the transmission side substrate 2a and the reception side substrate 2b. Have. In the following description, a member at the transmission side is given a suffix, and a member at the receiving side is given a suffix b.

  On the transmission side substrate 2a, a transmission side ferrule (transmission side optical fiber positioning component) 3a for accurately positioning the transmission side optical fiber 6a with respect to the light emitting element 4a is fixed by a fixing means such as an adhesive. A light emitting element 4a such as a VCSEL is attached to one end of the transmitting ferrule 3a so that the light emitting surface faces the end surface of the transmitting ferrule 3a.

  In addition, the transmission side optical fiber 6a here is a name for convenience. For example, when transmitting an optical signal from the first electronic device 20 of FIG. 1 to the second electronic device 30, the transmission-side optical fiber 6a of the optical transceiver module 1 attached to the first electronic device 20 that transmits the optical signal is For the optical transmission / reception module 1 attached to the second electronic device 30 that receives an optical signal, the optical fiber 6b is a reception side optical fiber. A plurality of optical fibers 6 a and 6 b that function as the transmission side optical fiber 6 a and the reception side optical fiber 6 b are combined as a single optical fiber cable 6.

  An insertion hole through which the transmission side optical fiber 6a is inserted so as to face the light emitting surface of the light emitting element 4a passes through the transmission side ferrule 3a, and the transmission side optical fiber 6a is inserted into the insertion hole. Then, it can position with sufficient precision with respect to the light emitting element 4a. The transmission side optical fiber 6a is inserted into the insertion hole, and one end thereof is opposed to the light emitting surface of the light emitting element 4a, and the intermediate portion (right end portion in FIG. 2) is gathered as the optical fiber cable 6 and extends to the outside of the housing 10. Has been. Thus, if the light emitting element 4a and the transmission side optical fiber 6a are arranged with high positioning accuracy using the transmission side ferrule 3a, the light from the light emitting element 4a can be efficiently input to the transmission side optical fiber 6a.

  The light emitting element 4a is fixed in a state where it is electrically connected to a lead frame 31a attached to one end face of the transmission side ferrule 3a by soldering or the like, and the lead frame 31a is an inter-element wiring 7a provided on the transmission side substrate 2a. And is electrically connected to a transmission-side semiconductor element 5a such as a driver IC provided on the transmission-side substrate 2a.

  On the opposite side of the transmission-side substrate 2a to the transmission-side ferrule 3a with respect to the longitudinal direction of the transmission-side optical fiber 6a, the transmission-side semiconductor element 5a is electrically connected to the first or second electronic device 20, 30 for external use on the transmission side. The wiring 8a is provided on the element mounting surface 21a, and electrically connects the first or second electronic device 20, 30 and the transmission-side semiconductor element 5a.

  The transmission side ferrule 3a and the transmission side semiconductor element 5a are both provided on the element mounting surface 21a of the transmission side substrate 2a. The transmission side substrate 2a is an element mounting surface of the reception side substrate 2b, which will be described later. It is arranged to face 21b.

  On the reception side substrate 2b, a reception side ferrule (reception side optical fiber positioning component) 3b is fixed by a fixing means such as an adhesive. A light receiving element 4b such as a photodiode as a light receiving element is attached to one end side of the receiving ferrule 3b so that the light receiving surface thereof faces the end face of the receiving ferrule 3b.

  In addition, an insertion hole through which the reception side optical fiber 6b is inserted so as to face the light receiving surface of the light receiving element 4b passes through the reception side ferrule 3b. One end of the light-receiving element 4 b is opposed to the light-emitting surface of the light-receiving element 4 b, and an intermediate portion (right end portion in FIG. 2) is gathered as an optical fiber cable 6 and extends to the outside of the housing 10.

  The light receiving element 4b is soldered to a lead frame 31b attached to the receiving side ferrule 3b, and the lead frame 31b is also provided on the receiving side substrate 2b via a receiving side inter-element wiring 7b provided on the receiving side substrate 2b. The receiving side semiconductor element 5b such as a transimpedance amplifier is electrically connected.

  The receiving side semiconductor element 5b is electrically connected to the first or second electronic device 20, 30 on the opposite side of the receiving side ferrule 3b of the receiving side substrate 2b with respect to the longitudinal direction of the receiving side optical fiber 6b. The wiring 8b is provided on the element mounting surface 21b, and the first or second electronic device 20, 30 and the receiving-side semiconductor element 5b are electrically connected.

  Both the receiving ferrule 3b and the light receiving semiconductor element 5b are provided on the element mounting surface 21b of the receiving substrate 2b, and the receiving substrate 2b faces the element mounting surface 21a of the transmitting substrate 2a. Are arranged as follows.

  The operation of the optical transceiver module 1 configured as described above will be described by taking as an example a case where a signal is transmitted from the first electronic device 20 to the second electronic device 30 in FIG.

  First, the electrical signal of the first electronic device 20 is input to the transmission-side semiconductor element 5 a via the transmission-side external wiring 8 a of the optical transmission / reception module 1 attached to the first electronic device 20. The transmission-side semiconductor element 5a outputs a current signal corresponding to the input electric signal to the light-emitting element 4a via the transmission-side inter-element wiring 7a and the lead frame 31a. The light emitting element 4a emits an optical signal according to the input current signal, and the optical signal is transmitted through the transmission optical fiber 6a (optical fiber cable 6).

  The optical signal transmitted through the optical fiber 6 enters the light receiving element 4b from the receiving optical fiber 6b of the optical transceiver module 1 attached to the second electronic device 30. The light receiving element 4b outputs a current signal according to the received optical signal, and this current signal is input to the light receiving side semiconductor element 5b through the lead frame 31b and the receiving side inter-element wiring 7b. The light-receiving-side semiconductor element 5b converts the input current signal into a voltage signal, amplifies it, and outputs it to the second external device 30 via the receiving-side external wiring 8b, from the first electronic device 20 to the second electronic device 30. A signal is transmitted to.

  The transmission side substrate 2a and the reception side substrate 2b configured as described above are provided inside the housing 10 so that the element mounting surfaces 21a and 21b face each other. Accordingly, the transmission ferrule 3a and the reception ferrule 3b are provided so as to face each other, and the transmission optical fiber 6a and the reception optical fiber 6b extending from the transmission ferrule 3a and the reception ferrule 3b are also opposed to each other. 10 to the outside.

  As described above, since the distance between the transmission optical fiber 6a and the reception optical fiber 6b is narrow, when these optical fibers 6a and 6b are combined into an optical fiber cable 6, the distance between the optical fibers 6a and 6b should be further reduced. Even if the optical fibers 6a and 6b are bent to form a bent portion, the bent portion can be reduced. Further, the longitudinal dimension of the optical fiber cable 6 of the optical transmission / reception module 1 can be reduced by the amount by which the bent portion is reduced.

  In the present embodiment, the transmission side substrate 2a and the reception side substrate are set so that the distance between the optical fibers in the optical fiber cable 6 is equal to the distance between the optical fibers 6a and 6b in the optical transmission / reception module 1. 2b and the positions where the insertion holes of the transmitting ferrule 3a and the receiving ferrule 3b are provided are adjusted. Therefore, since it is not necessary to bend the transmission side optical fiber 6a or the reception side optical fiber 6b to form a bent portion, the optical transmission / reception module 1 having high transmission efficiency can be provided. Further, according to the optical transceiver module 1 according to the present embodiment, the region A occupied by the bent portion 106a1 is compared with the case where a plurality of substrates are stacked with the element mounting surface facing the upper surface as shown in FIG. The longitudinal dimension of the optical fiber cable 6 can be reduced by that amount.

  The optical transceiver module 1 is arranged so that the element mounting surface 21a of the transmission side substrate 2a and the element mounting surface 21b of the reception side substrate 2b face each other. Therefore, the transmitting side member such as the light emitting element 4a and the receiving side member such as the light receiving element 4b are arranged side by side on a single substrate (arranged in a direction orthogonal to the longitudinal direction of the optical fibers 6a and 6b). ) Compared to the case, the width of the optical transceiver module 1 can be reduced, and the whole can be made compact. When the optical transceiver module 1 has multiple channels and transmits and receives a plurality of signals in parallel, the entire optical transceiver module 1 can be particularly compactly configured.

  In this optical transceiver module 1, the current flowing through the transmission-side inter-element wiring 7a from the transmission-side semiconductor element 5a to the light-emitting element 4a is relatively large (about 10 mA), while the light-receiving element 4b receives from the light-receiving-side semiconductor element 5b. Since the current flowing through the side element wiring 7b is relatively small (about 10 μA), the reception side element wiring 7b is susceptible to crosstalk.

  However, even if the optical transceiver module 1 is configured compactly as described above, the receiving-side inter-element wiring 7b that is easily affected by crosstalk is relatively large across the space occupied by the transmitting-side ferrule 3a and the receiving-side ferrule 3b. It is located on the opposite side of the transmission-side inter-element wiring 7a through which current flows, and the interval between the transmission-side inter-element wiring 7a and the reception-side inter-element wiring 7b can be set large. Therefore, it is possible to reduce the influence of crosstalk caused by the transmission-side inter-element wiring 7a of the reception-side inter-element wiring 7b. The crosstalk is further increased by increasing the height (the vertical dimension in FIG. 2) of the transmission-side ferrule 3a and the reception-side ferrule 3b to widen the distance between the transmission-side element wiring 7a and the reception-side element wiring 7b. Can be reduced.

1: optical transceiver module, 2a: transmission side substrate, 2b: reception side substrate, 21a, 21b: element mounting surface, 3a: transmission side optical fiber positioning component, 3b: reception side optical fiber positioning component, 4a: light emitting element, 4b : Light receiving element, 5a: transmission side semiconductor element, 5b: reception side semiconductor element, 6a: transmission side optical fiber, 6b: reception side optical fiber, 10: housing

Claims (1)

A light-emitting element, a transmission-side optical fiber positioning component that accommodates a transmission optical fiber that transmits light from the light-emitting element, and a transmission semiconductor element that electrically controls light emission of the light-emitting element are provided on the element mounting surface. A transmitter board,
A light receiving element, a receiving-side optical fiber positioning component that houses a receiving optical fiber that transmits light to the light receiving element, and a receiving semiconductor element that amplifies an electric signal from the light receiving element are provided on the element mounting surface. An optical transceiver module comprising a receiving side substrate,
The element mounting surface of the transmission side substrate and the element mounting surface of the reception side substrate are arranged to face each other.

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