JP4706611B2 - Optical transceiver - Google Patents

Description

  The present invention relates to an optical transceiver that transmits and / or receives an optical signal, and more particularly, to an optical transceiver that transmits a Gigabit class Ethernet (registered trademark) signal.

  In recent years, the Internet has been established as a communication infrastructure, and various types of industries and services have been taken in regardless of the type of information such as data communication, voice, and video, and its application range continues to expand. In line with this, the line capacity is steadily increasing. Among them, Ethernet (registered trademark) is widely used as a core technology widely used in home LAN (Local Area Network) and WAN (Wide Area Network) due to low cost and simple operability.

  In this situation, standardization of 10 Gigabit Ethernet (registered trademark) has already been completed, and network devices supporting 10 Gigabit have been developed by each company. Accordingly, optical transceivers (optical modules) are also used in medium-distance networks. An upgrade from 1 Giga to 10 Giga has been started with a transmission speed centering on the network. In addition, development and research of Ethernet (registered trademark) of 40 Giga to 100 Giga class with transmission speed exceeding 10 Giga has started.

  As such an optical transceiver, a four-wave CWDM (Coarse-WDM: Low-Density Wavelength Division) using an SFP (Small Form Pluggable) type optical transceiver for each channel of transmission and reception and four long-wavelength semiconductor lasers (LDs). Multiplexed) LX4 optical transceiver (a type of Ethernet (registered trademark) standard optical transceiver).

  As an example, an optical transmitter / receiver 141 (see, for example, Patent Document 1) as illustrated in FIG. 14 is mounted on rigid boards 142a to 142c, an optical transmission assembly (TOSA) 143 mounted on the rigid board 142a, and the rigid board 142c. The plurality of rigid boards 142a to 142c are connected using a flexible board 145 or a two-piece connector.

  The optical transmission assembly 143 includes four LDs, and the optical reception assembly 144 includes four PDs (photodiodes). In this optical transceiver 141, the other end of the rigid board 142c is fitted to a card edge connector that is an electrical connector provided in an information system device (network device). The optical transmission assembly 143 and the optical reception assembly 144 are optical fibers. Is routed through the case 146 and connected to an external optical fiber with a connector via connector plugs 147 and 148.

JP 2005-99769 A

  However, the SFP type optical transceiver has a small number of channels for each channel for transmission and reception, and is not compatible with the increase in the number of channels and the increase in speed desired in the future. Similarly, the conventional optical transmitter / receiver 141 has a small number of channels, and does not correspond to the increase in the number of channels and the increase in speed that are desired in the future.

  In addition, the conventional optical transceiver 141 has a complicated configuration because individual elements such as LDs and WDM optical components are connected to the optical fiber in the optical transceiver 141 in spite of the small number of channels. There is a problem that assembly is difficult.

  Further, as shown in FIG. 15, in the conventional optical transceiver 141, since the optical transmission assemblies 143 are mounted side by side on the rigid substrate 142a, each rigid substrate is provided in the case 146 by the amount corresponding to the optical transmission assembly 143. The space occupied by 142a to 142c is eroded, and as a result, the mounting area of the rigid substrates 142a to 142c is reduced.

  On the other hand, in the general conventional optical transceiver, the central axis of the electrical connector is different from the central axis of the optical connector. In this optical transceiver, since both the optical transmission assembly and the optical reception assembly are receptacles, there is a problem that the input / output positions are fixed and the degree of freedom in design is low. In addition, a support member for supporting the ferrule holding part in the case must be built with high accuracy, which increases the cost.

  In order to solve the problem of a low degree of design freedom, there is also an optical transceiver that uses a rigid-flex board (flex-rigid printed wiring board) as a circuit board in order to absorb a step of the central axis of light / electricity. However, the rigid flexible substrate is complicated and expensive to manufacture, and since there are few manufacturers, the optical transceiver is expensive.

  In addition, in the conventional conventional optical transceiver that is not the optical transceiver described above, but the optical fiber is not pigtailed, the center axis of the light / electricity is likely to be shifted, and the step of the center axis of the light / electricity is absorbed. In some cases, the leads of the LD of the optical transmission assembly and the PD of the optical reception assembly are lead-formed and mounted on the circuit board. In this case, since the lead length becomes long, there is a problem that the high frequency characteristics of the electric signal are poor.

  Furthermore, in optical transceivers that support multi-channel and high-speed operations that are desired in the future, it is considered that the crosstalk will increase further than the present because the signal on the transmitting side interferes with the signal on the receiving side. Therefore, it is important to suppress crosstalk as much as possible.

  Accordingly, an object of the present invention is to provide an optical transceiver having high performance, high reliability, and low cost.

The present invention was devised to achieve the above object, and the invention of claim 1 converts a plurality of electrical signals from information system equipment into optical signals and transmits them to a plurality of transmission optical fibers. In an optical transceiver for receiving a plurality of optical signals from a plurality of receiving optical fibers and converting them into electrical signals and transmitting them to the information system equipment, the optical system is electrically connected to the information system equipment. A circuit board having a connection terminal; an optical connector connected to the transmission / reception optical fiber; an optical transmission assembly mounted on the circuit board and having a light emitting element for converting an electrical signal from the circuit board into an optical signal; An internal transmission tape fiber having one end connected to the optical transmission assembly and the other end connected to the optical connector, and an internal reception tape fiber having one end connected to the optical connector. When being mounted on the circuit board has a light receiving element for converting an optical signal from the receiving optical fiber to an electric signal, and an optical receiver assembly that the other end of the internal receiving tape fiber is connected The optical transmitter assembly and the optical receiver assembly are arranged in a line on one surface side of the circuit board from the connection terminal side of the circuit board to the transmission / reception optical fiber side, and An optical transceiver in which the optical receiver assembly is mounted on a transmission / reception optical fiber side, and the optical transmission assembly is mounted on the circuit board on the back side of the optical reception assembly .

The invention of claim 2 converts a plurality of electrical signals from information system equipment into optical signals, transmits them to a plurality of transmission optical fibers, and receives a plurality of optical signals from a plurality of reception optical fibers. In addition, in an optical transceiver for converting this into an electric signal and transmitting it to the information system device, a circuit board having a connection terminal electrically connected to the information system device, and light connected to the transmission / reception optical fiber An optical transmitter assembly having a light emitting element mounted on the circuit board and converting an electrical signal from the circuit board into an optical signal, one end connected to the optical transmitter assembly, and the other end connected to the optical connector The internal transmission tape fiber, the internal reception tape fiber having one end connected to the optical connector, and the reception optical fiber mounted on the circuit board. A light receiving assembly that includes a light receiving element that converts an optical signal into an electrical signal, and to which the other end of the internal receiving tape fiber is connected. The optical transmitter assembly and the optical receiver assembly are arranged on one surface side of the circuit board so that the optical axis of the element is parallel, and a hollow is formed in the circuit board. Any one of the receiving assemblies is disposed on the cut-out hole, and is electrically connected to the other surface opposite to the one surface of the circuit board by a flexible board inserted through the cut-out hole. Alternatively, an optical transceiver in which the other of the optical receiving assembly is electrically connected to one surface of the circuit board through a flexible board .

A third aspect of the present invention is the optical transceiver according to the second aspect, wherein a multilayer substrate is used as the circuit board, and the circuit board has an entire ground layer between one surface and the other surface .

  According to the present invention, a high-performance and highly reliable optical transceiver can be realized by connecting a tape fiber to an optical transmission assembly or an optical reception assembly to form a multicore pigtail fiber.

  Preferred embodiments of the present invention will be described below with reference to the accompanying drawings.

  1 is a perspective view showing a main part of an optical transceiver that is a preferred embodiment of the present invention, FIG. 2 is a perspective view of FIG. 1 viewed from the connection terminal side, and FIG. 3 is a perspective view of FIG. FIG. 4 is a side view of FIG.

  As shown in FIGS. 1 to 4, the optical transceiver 1 according to the present embodiment is a pluggable multi-channel optical transceiver that is detachably provided in an information system device (network device) such as a switching hub or a media converter. In the present embodiment, an example of an optical transceiver that transmits a total of 2 × 12 channels, that is, a 24 channel type, and 3 Gbit / s signals per channel will be described.

  This optical transceiver 1 converts a plurality of electrical signals from information system equipment into optical signals and transmits them to a plurality of transmission optical fibers as transmission lines, while a plurality of reception lights as transmission paths. It receives a plurality of optical signals from the fiber and converts them into electrical signals for transmission to information system equipment.

  The optical transceiver 1 includes a strip-shaped circuit board 2 made of one rigid board, an optical transmission assembly (TOSA) 3 and an optical reception assembly (ROSA) 4 respectively mounted on the circuit board 2.

  The other end of the circuit board 2 on the information system device side is provided with a card edge portion 6 formed by forming a plurality of connection terminals 5 for connection to the information system device. The hot-swap of the optical transceiver 1 is enabled by fitting into the card edge connector provided in the information system equipment.

  The optical transmission assembly 3 includes an LD module 7 having an LD element as a light emitting element that converts a plurality of electrical signals from the circuit board 2 into optical signals, and 1 collects optical signals from the LD elements in a lump. It is mainly composed of a lens block 8t having two (or two or more) lenses and a one-stage MT optical connector 9t connected to the lens block 8t.

  As the LD element, a VCSEL (surface emitting laser) array in which 12 LD chips are arranged in an array is used. The LD module 7 is a unit in which an LD element is housed in a ceramic package 10 and hermetically sealed. A lens block 8t is fixed to the front side of the ceramic package 10, and a plurality of solder balls are attached to the rear surface of the ceramic package 10 in a grid pattern. That is, the ceramic package 10 constitutes a BGA (Ball Grid Array) solder. A non-axisymmetric toric lens is used as the lens provided in the lens block 8t.

  The optical transmission assembly 3 is arranged so that the optical axis of the LD element is parallel to the connection terminal 5 side (the back side of the optical reception assembly 4) on the surface of the circuit board 2 and to the front and back surfaces (length direction in the drawing) of the circuit board 2. The LD module 7 is mounted in an upright posture.

  One end portion of the flexible substrate 11t is connected to the rear surface of the ceramic package 10, and the bent other end portion of the flexible substrate 11t is connected to the circuit pattern on the circuit substrate 2. A plurality of terminals 12 connected to the circuit board 2 are formed on the front and back surfaces of the other end of the flexible board 11t. The optical transmission assembly 3 and the circuit board 2 are electrically connected via the flexible board 11t. The terminal 12 formed on the surface of the other end of the flexible substrate 11t is a dummy terminal formed so that the optical receiving assembly 4 and the flexible substrate 11t can be electrically connected.

  A one-stage MT optical connector 9t is connected to the front surface of the lens block 8t of the optical transmission assembly 3, and the internal transmission for transmitting the optical signal from the optical transmission assembly 3 to the transmission optical fiber is connected to the first-stage MT optical connector 9t. One end of the trusted tape fiber 13t is connected. The single-stage MT optical connector is formed by forming a plurality of fiber insertion holes in a left and right parallel in a ferrule made of resin, and holding and fixing one optical fiber in each of these hollow portions. The tape fiber is a plurality of single-core optical fibers arranged in parallel in the left-right direction (12 in the figure), and the arranged fibers are collected in a tape shape.

  On the transmission / reception optical fiber side of the circuit board 2, as an optical connector to be connected to the other end of the transmission / reception optical fiber, a male two-stage MPO (multi-fiber batch connection using a ferrule of an MT (Mechanically Transferable) optical connector) An optical connector 14 is provided. The male two-stage MPO optical connector 14 is held and fixed to a case 60 (see FIG. 6 described later).

  The male two-stage MPO optical connector 14 includes a two-stage MT optical connector 15 in which the other end of the internal transmission tape fiber 13t is connected to the upper stage and one end of the internal reception tape fiber 13r is connected to the lower stage. The claw member (receptacle part) 16 is attached to the two-stage MT optical connector 15 and engages with a female two-stage MPO optical connector as an external optical connector.

  The claw member 16 and the recess of the female two-stage MPO optical connector constitute a latch mechanism. A transmitting / receiving optical fiber is connected to the female two-stage MPO optical connector. An optical cable may be used as the transmission / reception optical fiber, or a tape fiber may be used as a relay transmission path in the preceding stage.

  By inserting the female two-stage MPO optical connector into the claw member 16 and fitting the male two-stage MPO optical connector 14 and the female two-stage MPO optical connector within the claw member 16, the internal transmission tape fiber 13t And the transmission optical fiber are connected, and the reception optical fiber and the internal reception tape fiber 13r are connected.

  The optical receiving assembly 4 includes a first-stage MT optical connector 9r to which the other end of the internal receiving tape fiber 13r is connected, and the first-stage MT optical connector 9r to which a plurality of optical signals from the internal receiving tape fiber 13r are connected. PD having a lens block 8r having one (or two or more) lenses for condensing each of the light and a PD element as a light receiving element for converting a plurality of optical signals from the lens block 8r into electric signals, respectively. The module 17 is mainly configured. A non-axisymmetric toric lens is used as the lens provided in the lens block 8r.

  As the PD element, a PD array in which 12 PD chips are arranged in an array is used. The PD module 17 is a device in which a PD element is housed in a ceramic package 10 and hermetically sealed. The posture of the optical receiver assembly 4 is the same as that of the optical transmitter assembly 3.

  The optical receiver assembly 4 is mounted on the surface of the circuit board 2 on the transmission / reception optical fiber side (the front side of the optical transmission assembly 3). In the present embodiment, the optical transmission assembly 3 and the optical reception assembly 4 are mounted so as to be in a straight line on the surface of the circuit board 2.

  More specifically, a hollow hole (opening) 18 is formed in the mounting portion of the optical receiving assembly 4 on the circuit board 2, and the optical receiving assembly 4 is disposed on the hollow hole 18, so that the optical receiving assembly 4 and the circuit board 2 are arranged. Are electrically connected to each other at the other end of the flexible substrate 11r inserted through the cutout hole 18.

  In the present embodiment, the flexible substrate 11r has the same configuration as the flexible substrate 11t. A plurality of terminals similar to the flexible substrate 11t are formed on the front and back surfaces of the other end of the flexible substrate 11r. In the flexible substrate 11r, a terminal formed on the back surface of the other end is a dummy terminal, and is used when electrically connected to the optical transmission assembly 3.

  When a multilayer substrate is used as the circuit substrate 2, one of the layers is preferably a ground (GND) layer (a solid GND layer). The terminal 12 of the flexible board 11t and a part of the terminal of the flexible board 11r are electrically connected to the GND layer of the entire surface, the GND pattern of the circuit board 2, or the case of the optical transceiver 1 described later with reference to FIG. To do.

  As shown in FIG. 6, the circuit board 2, the optical transmission assembly 3, the internal transmission tape fiber 13t, the internal reception tape fiber 13r, the optical reception assembly 4, and the male two-stage MPO optical connector 14 The lower case 60d having a substantially U-shaped cross section and the upper case 60u having a substantially U-shaped cross section are accommodated in a vertically divided case 60. The case 60 is formed of a metal having high heat dissipation such as Al. In the present embodiment, as the case 60, an industry standard (MSA) X2 standard case was used. That is, the optical transceiver 1 is an X2-type optical transceiver, which is about the size of a business card.

  In assembling the optical transceiver 1, the optical transmission assembly 3 and the optical reception assembly 4 are arranged on the circuit board 2, and the assemblies 3 and 4 and the circuit board 2 are electrically connected by the flexible boards 11t and 11r.

  On the other hand, the one-stage MT optical connector 9t is arranged at one end of the internal transmission tape fiber 13t, the one-stage MT optical connector 9r is arranged at the other end of the internal reception tape fiber 13r, and the other end of the internal transmission tape fiber 13t is arranged at the upper stage. In addition, one in which one end of the internal receiving tape fiber 13r is arranged in the lower stage and the two-stage MT optical connector 15 is connected is prepared.

  The first-stage MT optical connector 9 t is connected to the lens block 8 t of the optical transmission assembly 3, and the first-stage MT optical connector 9 r is connected to the lens block 8 r of the optical reception assembly 4. At this time, the internal transmission tape fiber 13t is wired so that the internal transmission tape fiber 13t gets over the optical reception assembly 4.

  A claw member 16 is attached to the two-stage MT optical connector 15 to form a male two-stage MPO optical connector 14. Thereafter, the circuit board 2 is housed in the lower case 60d, and finally the upper case 60u is attached to the lower case 60d with screws, thereby completing the optical transceiver 1.

  The operation of this embodiment will be described.

  First, the operation of the optical transceiver 1 will be briefly described. The optical transmitter / receiver 1 inserts the optical transmitter / receiver 1 into an information system device (see FIG. 10 described later), and a female type 2 in which a transmission / reception optical fiber is connected to a claw member 16 of a male two-stage MPO optical connector 14. It operates with the stage MPO optical connector connected.

  The twelve transmission electrical signals from the information system device are converted into twelve optical signals by the LD element, and these optical signals are transmitted to the transmission optical fiber via the internal transmission tape fiber 13t. On the other hand, twelve optical signals from the receiving optical fiber are received via the internal transmission tape fiber 13r, converted into twelve electric signals by the PD element, and information system equipment as twelve receiving electric signals. Is transmitted.

  The optical transceiver 1 according to the present embodiment includes an internal transmission tape fiber 13t having one end connected to the optical transmission assembly 3 and the other end connected to the transmission optical fiber via a male two-stage MPO optical connector 14. The receiving optical fiber includes an internal receiving tape fiber 13r having one end connected to the receiving optical fiber via a male two-stage MPO optical connector 14 and the other end connected to the optical receiving assembly 4.

  That is, the optical fiber connected to the optical transmission assembly 3 and the optical reception assembly 4 is a pigtail fiber. In other words, the light output side is pigtailed and the light input side is also pigtailed.

  As a result, the optical transceiver 1 is a highly integrated version of the conventional SFP optical transceiver for each channel for transmission and reception and the optical transceiver 141 of FIG. It is an optical transceiver that can be easily handled.

  In addition, the optical transceiver 1 can absorb the height adjustment (step difference between the optical / electrical central axes) between the optical component and the electrical component with the pigtail fiber, and the mechanical components of the optical transmission assembly 3 and the optical reception assembly 4 can be absorbed. Can absorb stress. Further, the case 60 does not require the processing of the optical transmitter assembly 3 and the optical receiver assembly 4 for the receptacle, and the processing cost can be reduced.

  For this reason, there is no restriction | limiting in the input / output position of the optical transmission assembly 3 or the optical reception assembly 4, and the freedom degree of design is large. In other words, since there is no restriction on the input / output position of the optical transceiver assembly, it is possible to adopt an optimal structure in terms of optical characteristics and electrical characteristics as the optical transceiver. Therefore, the optical transmission assembly 3 and the optical reception assembly 4 can be disposed at free positions on the circuit board 2 by pigtailing.

  Moreover, since one rigid board can be used as the circuit board 2 by pigtailing, it can be manufactured at a lower cost than the rigid flexible board, and the optical transceiver 1 becomes cheaper. Since the board manufacturing process is simplified, lead time and manufacturing time are also shortened.

  Here, a general conventional optical transceiver includes a stub ferrule in the ferrule holding unit. Since the fiber in the stub ferrule is SMF (single mode fiber), the length is as short as several millimeters and has a linear structure, higher order mode components generated in the optical coupling part cannot be removed. For this reason, a general conventional optical transceiver has a problem that the power of the optical signal varies depending on the type of fiber (SMF or MMF (multimode fiber)) connected to the stub ferrule.

  However, in the optical transceiver 1, a stub ferrule is used by taking a distance of an optical signal path by bending the optical signal or bending the internal transmission tape fiber 13 t or the internal reception tape fiber 13 r (adding R). In this case, it is possible to eliminate a higher order mode that becomes a problem.

  Therefore, the optical transceiver 1 is a high-performance, highly reliable and inexpensive optical transceiver.

  Since the optical transmitter / receiver 1 mounts the optical transmission assembly 3 and the optical reception assembly 4 on the circuit board 3, the space occupied by the circuit board 2 in the case 60 is not eroded by the optical transmission assembly 3 and the optical reception assembly 4. As compared with the conventional optical transceiver 141, the mounting area of the circuit board 2 is increased. Further, it is not necessary to divide the circuit board according to the shape of the optical transmission assembly 3 or the optical reception assembly 4, and a single rigid board can be used as the circuit board 2.

  Since the circuit board 2 has the male two-stage MPO optical connector 14 including the two-stage MT optical connector 15 as an optical connector for connecting to the transmission / reception optical fiber, the internal transmission / reception tape fibers 13t and 13r are used for transmission / reception. It can be connected to optical fiber in a compact manner.

  In the optical transceiver 1, an optical reception assembly 4 is mounted on the transmission / reception fiber side of the circuit board 2, and an optical transmission assembly 3 is mounted on the circuit board 2 on the back side of the optical reception assembly 4.

  For this reason, the optical transceiver 1 can confine noise in the vicinity of the optical transmission assembly 3 in which the optical transmission assembly 3 and the optical reception assembly 4 do not overlap in the width direction of the circuit board 2 and easily radiate electromagnetic waves. It is possible to protect a small electric signal that is sensitive to noise of the receiving assembly 4.

  Therefore, the optical transmitter / receiver 1 can suppress crosstalk as much as possible even in an optical transmitter / receiver corresponding to further increase in the number of channels and speed desired in the future, and is strong against EMI (electromagnetic interference).

  Further, by mounting the optical transmission assembly 3 on the back side of the circuit board 2, the wiring for transmitting a high-speed electrical signal from the information system device to the optical transmission assembly 3 is made as short as possible, as close as possible to the card edge portion 6, and the signal Can also be prevented.

  In the above embodiment, the optical receiving assembly 4 is mounted on the front side of the circuit board 2 and the optical transmitting assembly 3 is mounted on the back side. However, the optical receiving assembly 4 includes an amplifier that amplifies an electric signal, and the circuit board 2 has a waveform shaping circuit. On the contrary, the optical transmission assembly 3 may be mounted on the front side of the circuit board 2 and the optical reception assembly 4 may be mounted on the back side.

  In short, the optical transmission assembly 3 and the optical reception assembly 4 may be mounted on the circuit board 2 so that the distances from the connection terminals 5 are different from each other.

  Since the optical transmission assembly 3 and the optical reception assembly 4 are electrically connected to the circuit board 2 via the flexible boards 11t and 11r, the optical transmission assembly 3 and the optical reception assembly 4 and the circuit board 2 in an upright posture are arranged. Can be easily connected to the

  Further, a hollow 18 is formed in the mounting portion of the optical receiving assembly 4 on the circuit board 2, the optical receiving assembly 4 is disposed on the hollow 18, and the optical receiving assembly 4 and the circuit board 2 are connected to the hollow 18. The other end of the inserted flexible substrate 11r is electrically connected.

  As a result, in the optical transceiver 1, since the electrical signal on the transmission side is transmitted on the front surface of the circuit board 2 and the electrical signal on the reception side is transmitted on the back surface of the circuit board 2, crosstalk can be further suppressed, and EMI It becomes stronger.

  On the other hand, it is conceivable to form a through hole in the circuit board 2 and send and receive transmission / reception signals separately on the front and back surfaces of the circuit board 2. However, it takes time to form a through hole, and the signal is transmitted by the length of the through hole. It will deteriorate.

  Conversely, a hole is formed in the mounting portion of the optical transmission assembly 3 on the circuit board 2, the optical transmission assembly 3 is disposed on the hole, and the optical transmission assembly 3 and the circuit board 2 are inserted through the hole. You may electrically connect in the other end part of the flexible substrate 11t.

  In the optical transceiver 1, a hole is formed so as to be slightly larger than the outer shape of the optical receiver module 4, and the optical receiver module 4 is fixed by the case 60. However, the optical transceiver 1 is at least large enough to allow the flexible substrate 11 r to be inserted. A hollow hole may be formed.

  Since the terminal 12 of the flexible board 11t and a part of the terminals of the flexible board 11t are electrically connected to the entire GND layer, the GND pattern of the circuit board 2, or the case 60 of FIG. It can be done reliably. In particular, when the entire GND layer is formed on the circuit board 2, the entire GND layer serves as a shield that separates the front and back surfaces of the circuit board 2, thereby further reducing crosstalk.

  Further, if the internal transmitting / receiving tape fibers 13t and 13r are tape fibers, the degree of freedom in design is low with respect to the width direction of the circuit board. Therefore, as shown in FIG. 5, the internal transmission tape fiber 13t and / or the internal reception tape fiber may be separated at least in the length direction. Thereby, in the optical transceiver 1, the degree of freedom in design is increased not only in the length direction of the circuit board but also in the width direction.

Next, a second embodiment as a reference example will be described.

  As shown in FIG. 7, the optical transceiver 71 has an optical transmission assembly 73 mounted on the front surface of the circuit board 2 and an optical reception assembly 74 mounted on the back surface of the circuit board 2. Thus, the optical transmission assembly 73 and the optical reception assembly 74 are separately mounted.

  In the optical transceiver 71, an optical receiving assembly 74 is mounted on the front side of the back surface of the circuit board 2, and an optical transmitting assembly 73 is mounted on the back side of the surface of the circuit board 2. A multilayer substrate was used as the circuit board 2, and one of the layers was the entire GND layer 75. The lens blocks 78t and 78r of the light transmitting assembly 73 and the light receiving assembly 74 are reflection type lens blocks that have a mirror 76 and reflect the emitted light or incident light of the optical element to be output and input.

  Since the optical transmitter / receiver 71 mounts the optical transmitter / receiver assembly on the front and back surfaces of the circuit board 2, a space in the height direction is required in the main part thereof compared to the optical transmitter / receiver 1 of FIG. 1. For this reason, as the case, it is preferable to use the XENPAK standard case instead of the X2 standard case of FIG. 6 or a low-profile (thin) optical transceiver assembly.

  This optical transmitter / receiver 71 also provides the same effects as the optical transmitter / receiver 1 of FIG.

  A third embodiment will be described.

  A conventional optical transceiver 101 used in a network 100 as shown in FIG. 10 is often connected to an optical transmission / reception optical fiber 102 as a transmission path via a multi-core optical connector 103. Although the multi-core optical connector 103 is good in terms of a batch connection, there are problems such as poor insertion / removability, dirt easily attached to the connector, and difficult cleaning.

  Further, some users not only connect optical transceivers to external information system devices in a lump, but also request to connect optical transceivers separately at user home u or building b.

  As in the network 100, when the other party that exchanges optical signals is different for each channel, the multi-core optical connector 103 requires parts for branching, such as the branching device 104. The branching device 104 needs to include a multi-core optical connector 105, a branching unit 106, and a single-core optical connector 107.

  Furthermore, when the conventional optical transceiver 101 is used, a transmission loss of 0.5 dB occurs between the connectors 103 and 105, and a transmission loss of 0.1 dB occurs in the single-core optical connector 107, and a total transmission loss of 0.6 dB per transmission line occurs. is there.

  Therefore, as shown in FIG. 8, in the optical transceiver 81 according to the third embodiment, a plurality of male two-stage MPO optical connectors 14 of the optical transceiver 1 described in FIG. An optical interface unit 83 having 24 single-core separated optical connectors 82 (24 in FIG. 8) was connected.

  The optical interface unit 83 has one end connected to the female two-stage MPO optical connector that fits with the male two-stage MPO optical connector 14, and the other end separated into a single core. And an external tape fiber 85 and a plurality of single-core separated optical connectors (SC optical connectors) 82 connected to the other end of the external tape fiber 85. In FIG. 8, the female two-stage MPO optical connector is in a protective member 84 provided on the outer periphery thereof.

  The external tape fiber 85 is two bundles of tape fibers 85T and 85R each having one end portion arranged in parallel with 12 single-core optical fibers, and the other end portion is a total of 24 single fibers separated from the tape fibers 85T and 85R. The core optical fibers 85t and 85r. A binding band 86 is attached to the boundary between the tape fibers 85T and 85R and the optical fibers 85t and 85r to prevent the tape fibers 85T and 85R from separating.

  In the optical transmitter / receiver 81, the optical interface is not a multi-core optical connector but a single-core optical connector by connecting an optical interface unit 83 having a single-core separated optical connector 82 to the terminal to the optical transceiver 1 of FIG. It has a fiber pigtail structure.

  For this reason, the network 90 as shown in FIG. 9 can be easily constructed according to the user's request by simply inserting and removing the required number of single-core separated optical connectors 82 into the mating connector, and the transmission path, user home u, The optical transceiver 81 can be easily connected to the building b, from one information system device 91A to the other information system device 91B.

  The network 90 does not require the branching device 104 as in the network 100 of FIG. 10, and only a transmission loss of 0.1 dB occurs in the single-core separation optical connector 82. Therefore, the transmission loss per transmission line is also 0.1 dB. And low loss.

  Further, as the external tape fiber used for the optical interface unit, a fiber separated over the entire length may be used. The optical transceiver to which the optical interface unit is connected is not limited to the optical transceiver 1 of FIG.

  As a modification of the optical transceiver 81, without using the male two-stage MPO optical connector 14 or the female two-stage MPO optical connector, the internal transmitting / receiving tape fibers 13t and 13r in FIG. The extended portion may be used as the external tape fiber 85 or the single-core optical fibers 85t and 85r.

  As shown in FIG. 11, as the optical interface unit, two single-core optical fibers are vertically arranged in the vertical direction on the transmission / reception optical fiber side, and the two serially separated optical connectors 112 are combined into one by the ferrule unit. The optical interface unit 113 having a plurality (6 in FIG. 11 but 12 in reality) may be used.

  The same external tape fiber 85 as that described above can be used as the external tape fiber connected to the cascaded duplex optical connector 112.

  Usually, since communication is performed as a set of two single-core optical fibers, when the optical interface unit 113 having the cascaded double-separated optical connector 112 is used, one set is transmitted and received compared to the optical interface unit 83 of FIG. The single-core optical fiber can be easily inserted and removed, making it easy to construct a network and connect to external terminals.

  As shown in FIG. 12, as a modification of the column double separated optical connector 112, a convex portion 121 and a concave portion 122 for connecting / separating adjacent column double separated optical connectors 112 to each other are formed. Also good. By fitting the convex portions 121 and the concave portions 122 as necessary, the optical transceiver can be connected only to a network or an external terminal to be connected with a desired number of channels.

  In addition, as shown in FIG. 13, two or more single-core optical fibers (6 in FIG. 13 but actually 12 on the transmission / reception side) are arranged in parallel on the left and right as the optical interface unit as shown in FIG. Alternatively, an optical interface unit 133 having parallel separation optical connectors 132t and 132r in which the ferrule units are combined one by one may be used.

  The external tape fiber connected to the parallel separation optical connectors 132t and 132r is a normal tape fiber.

  In other words, if an optical interface unit having a multi-core separated optical connector with two or more cores on the transmission / reception optical fiber side is used, a network can be constructed with the transmission side or reception side set as one set while suppressing an increase in transmission loss. Or an external terminal and an optical transceiver can be connected.

It is a perspective view which shows the principal part of the optical transmitter-receiver which is suitable embodiment of this invention. It is the perspective view which looked at FIG. 1 from the connecting terminal side. It is the perspective view which looked at FIG. 2 from the back surface side. It is a side view of FIG. It is a perspective view which shows an example of the tape fiber for internal transmission / reception. 1 is an external view of an optical transceiver showing a preferred embodiment of the present invention. It is a side view which shows the principal part of the optical transmitter-receiver which is 2nd Embodiment as a reference example . It is an external view of the optical transceiver which shows the 3rd Embodiment of this invention. It is the schematic which shows an example of the network using the optical transmitter-receiver shown in FIG. It is the schematic which shows an example of the network using the conventional optical transmitter / receiver. It is a perspective view of a column double separation optical connector. It is a perspective view which shows an example of a 2 column separation optical connector. It is a perspective view which shows an example of a parallel isolation | separation optical connector. It is a disassembled perspective view of the conventional optical transmitter-receiver. FIG. 15 is an enlarged perspective view of the vicinity of the optical transmission assembly in the conventional optical transceiver illustrated in FIG. 14.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Optical transceiver 2 Circuit board 3 Optical transmission assembly 4 Optical reception assembly 5 Connection terminal 13t Internal transmission tape fiber 13r Internal reception tape fiber 14 Male MPO optical connector (optical connector)

Claims (3)

Converts multiple electrical signals from information system equipment into optical signals, transmits them to multiple transmission optical fibers, receives multiple optical signals from multiple reception optical fibers, and converts them to electrical signals In the optical transceiver for transmitting to the information system equipment,
A circuit board having a connection terminal electrically connected to the information system device;
An optical connector connected to the transmission / reception optical fiber;
An optical transmission assembly having a light emitting element mounted on the circuit board and converting an electrical signal from the circuit board into an optical signal;
An internal transmission tape fiber having one end connected to the optical transmission assembly and the other end connected to the optical connector;
An internal receiving tape fiber having one end connected to the optical connector;
A light receiving assembly mounted on the circuit board, having a light receiving element for converting an optical signal from the receiving optical fiber into an electrical signal, and to which the other end of the internal receiving tape fiber is connected ;
Equipped with a,
The optical transmission assembly and the optical reception assembly are arranged in a line on one side of the circuit board from the connection terminal side of the circuit board to the transmission / reception optical fiber side, and the transmission / reception of the circuit board is performed. The optical receiver assembly is mounted on the optical fiber side, and the optical transmitter assembly is mounted on the circuit board on the back side of the optical receiver assembly.
Optical transceiver. Converts multiple electrical signals from information system equipment into optical signals, transmits them to multiple transmission optical fibers, receives multiple optical signals from multiple reception optical fibers, and converts them to electrical signals In the optical transceiver for transmitting to the information system equipment,
A circuit board having a connection terminal electrically connected to the information system device;
An optical connector connected to the transmission / reception optical fiber;
An optical transmission assembly having a light emitting element mounted on the circuit board and converting an electrical signal from the circuit board into an optical signal;
An internal transmission tape fiber having one end connected to the optical transmission assembly and the other end connected to the optical connector;
An internal receiving tape fiber having one end connected to the optical connector;
A light receiving assembly mounted on the circuit board, having a light receiving element for converting an optical signal from the receiving optical fiber into an electrical signal, and to which the other end of the internal receiving tape fiber is connected;
With
On the circuit board, the optical transmitter assembly and the optical receiver assembly are arranged on one surface side of the circuit board so that the front and back surfaces thereof and the optical axes of the light emitting element and the light receiving element are parallel to each other,
Form a hole in the circuit board,
Either one of the optical transmitter assembly and the optical receiver assembly is disposed on the cutout hole, and is electrically connected to the other surface opposite to the one surface of the circuit board by a flexible board inserted through the cutout hole. Connected, and electrically connected the other of the optical transmitter assembly or the optical receiver assembly to one surface of the circuit board through a flexible substrate,
Optical transceiver. 3. The optical transceiver according to claim 2 , wherein a multilayer board is used as the circuit board, and the circuit board has a whole ground layer between one surface and the other surface .

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