JP2016219986A - Optical Communication Module - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an optical communication module capable of reducing time and cost necessary for adjustment and inspection.SOLUTION: Sub modules 200 and 300 comprise: optical devices (a laser diode 210 and a photodiode 310); circuit groups (communication ASICs 220 and 320) for controlling the operation of the optical devices (the laser diode 210 and the like); storage units (EEPROMs 230 and 330) for storing in advance setting information necessary for the operation of the optical devices (the laser diode 210 and the like) in the combination of the optical devices (the laser diode 210 and the like) and the circuit groups (the communication ASIC 220 and the like), respectively. The controller 120 sets the setting information stored in the storage units (the EEPROM 230 and the like) to the circuit groups (the communication ASIC 220 and the like), and the circuit groups (the communication ASIC 220 and the like) control the operation of the optical devices (the laser diode 210 and the like) on the basis of the setting information.SELECTED DRAWING: Figure 1

Description

  The present invention relates to an optical communication module.

  In the field of optical communication, an optical communication module may be used. For example, the optical communication module disclosed in the following Patent Document 1 is compatible with several standardized communication specifications, so that it can be monitored and controlled via a built-in controller and a communication interface with the outside. It has become.

  The optical communication module includes optical devices such as PD (Photo Diode) and LD (Laser Diode), and other elements such as an LD driver (drive circuit), CDR (Clock Data Recovery), TIA (Trans Impedance Amplifier), and the like. The circuit group provided with is included. Particularly in recent years, miniaturization and multi-functionalization of semiconductor processes of communication ASIC (application specific integrated circuit) have been promoted. As a result, in the optical communication module, many of the functions of the above-described circuit group are being realized by one ASIC.

Japanese Patent No. 4414968

  Optical devices such as PD and LD may have different characteristics even when manufactured under similar manufacturing conditions (having individual variations). The optical communication module is designed so that desired characteristics can be obtained even if there are individual variations in optical devices. For example, in the manufacturing process, in a state where the optical device or the like is mounted on the optical communication module, the parameters are adjusted so as to satisfy a predetermined product standard by correcting the operation condition or the like for individual variations of the optical device. . Further, after the adjustment, an inspection for confirming that the optical communication module operates with desired characteristics is also performed based on the adjusted parameters.

  On the other hand, in the optical communication module, there is a demand for improving the communication speed. As a technique for improving the communication speed, for example, there are techniques for increasing the number of parallel transmission lanes and increasing the modulation rate. In particular, recent optical communication modules tend to increase transmission lanes in order to increase the bandwidth. For example, a conventional one-lane transmission / reception configuration for transmitting / receiving a single optical signal has been used, but at present, there are many optical communication modules having a multi-lane transmission / reception configuration such as 4 lanes or 10 lanes.

  An optical device may be provided for each transmission lane. In that case, the adjustment and inspection described above are performed for each transmission lane. Therefore, when the transmission lane increases in the optical communication module, the number of adjustments and inspections increases, which takes time and cost.

  One embodiment of the present invention provides an optical communication module capable of reducing time and cost for adjustment and inspection.

  A shining communication module according to an aspect of the present invention includes an optical device, a circuit group that controls the operation of the optical device, and setting information necessary for the operation of the optical device in a combination of the optical device and the circuit group in advance. A storage unit that stores the sub-module, and a controller that can communicate with the storage unit and the circuit group via the first signal line, the controller via the first signal line The setting information is read from the storage unit and set in the circuit group, and the circuit group controls the operation of the optical device according to the setting information set by the controller.

  ADVANTAGE OF THE INVENTION According to this invention, the time and cost concerning adjustment and a test | inspection in an optical communication module can be reduced.

It is a figure which shows schematic structure of the optical communication module which concerns on embodiment of this invention. It is a figure which shows an example of the functional block of the submodule of FIG. It is a figure which shows an example of the functional block of the submodule of FIG. It is a figure which shows an example of schematic structure of the optical communication module which concerns on another embodiment of this invention. It is a figure which shows an example of schematic structure of the optical communication module which concerns on another embodiment of this invention. FIG. 2 is a diagram illustrating an example of a recording format stored in EEPROMs 230 and 330 in FIG. 1. It is a figure which shows another example of the recording format memorize | stored in EEPROM230,330 of FIG.

[Description of Embodiment of Present Invention]
First, the contents of the embodiments of the present invention will be listed and described.

  An optical communication module according to an aspect of the present invention includes an optical device, a circuit group that controls the operation of the optical device, and setting information necessary for the operation of the optical device in a combination of the optical device and the circuit group. A storage unit that stores the sub-module, and a controller that can communicate with the storage unit and the circuit group via the first signal line, the controller via the first signal line The setting information is read from the storage unit and set in the circuit group, and the circuit group controls the operation of the optical device according to the setting information set by the controller.

  In this optical communication module, the submodule includes an optical device and a circuit group that controls the operation of the optical device. Optical communication is performed by controlling such a submodule by the controller. The submodule includes a storage unit, and the storage unit stores in advance setting information necessary for the operation of the optical device in the combination of the optical device and the circuit group. The controller reads the setting information from the storage unit and sets the setting information in the circuit group. The circuit group controls the operation of the optical device in accordance with the setting information set by the controller, so that the submodule has a desired characteristic. Can be operated. According to this optical communication module, adjustment of parameters for correcting individual variations of optical devices in a state in which a submodule including an optical device or the like is mounted on the optical communication module, and inspection after the adjustment are unnecessary. As a result, the time and cost required for adjustment and inspection can be reduced. In addition, since processing for reading the setting information from the storage unit of the submodule and setting the setting information in the circuit group of the submodule is executed by the controller, for example, a software submodule for realizing such processing It is also possible to eliminate the need to write to.

  The optical communication module may further include a mounting portion to which the submodule can be attached and detached, and the submodule may be electrically connected to the controller via the first signal line by being mounted on the mounting portion. Thereby, it becomes easy to mount the submodule on the optical communication module and to remove it from the optical communication module. Furthermore, electrical connection and release between the submodule and the controller can be facilitated. For example, even when a failure occurs in the submodule, the submodule can be easily replaced. Since the storage unit included in the replaced submodule stores in advance setting information for the submodule to obtain desired characteristics, a parameter for correcting individual variations of the optical device again after replacement of the submodule. There is no need to perform adjustment and post-adjustment inspections.

  The controller may be configured to be able to communicate with the outside of the optical communication module via the second signal line. For example, if the controller is adapted to various communication methods, the optical communication module can be incorporated into various external devices and used.

  The optical device may include an optical transmission device that transmits a transmission optical signal, and the setting information may include information for the optical transmission device to operate with desired transmission characteristics in a predetermined wavelength band of the transmission optical signal. As a result, the submodule can be operated with desired transmission characteristics.

  The optical device may include an optical receiving device that receives a received optical signal, and the setting information may include information for the optical receiving device to operate with desired reception characteristics in a predetermined wavelength band of the received optical signal. Thereby, the submodule can be operated with desired reception characteristics.

  A plurality of submodules corresponding to different wavelength bands are mounted on the mounting unit, and the controller stores setting information stored in advance in each storage unit of the plurality of submodules via the first signal line. The read setting information may be set in each circuit group. Thereby, a plurality of submodules corresponding to different wavelength bands can be operated with desired characteristics. In this case, for any of the submodules, adjustment of parameters for correcting individual variations of the optical device in a state where the submodule is mounted on the optical communication module and inspection after the adjustment are unnecessary.

  The circuit group includes a control device in which setting information is set, and the storage unit sets designation address information for the controller to designate the control device via the first signal line and setting information in the control device. The memory address information and the setting information may be stored in association with each other. As a result, the controller operates each submodule with desired characteristics simply by executing the process of writing the setting information to the memory address for setting the setting information in the control device according to the information stored in the storage unit. Can be made. Therefore, for example, even when different types of submodules are mounted, the submodules can be appropriately operated. That is, it is possible to flexibly cope with various types of submodules.

  The circuit group may be manufactured as a single semiconductor integrated circuit. Thereby, integration of a circuit group can be achieved.

[Details of the embodiment of the present invention]
A specific example of the optical communication module according to the embodiment of the present invention will be described below with reference to the drawings. In addition, this invention is not limited to these illustrations, is shown by the claim, and intends that all the changes within the meaning and range equivalent to a claim are included.

  FIG. 1 is a diagram showing a schematic configuration of an optical communication module 100 according to an embodiment of the present invention. The optical communication module 100 is used for optical communication. The optical communication module 100 has an optical signal transmission function and a reception function. The transmission function includes, for example, a function of receiving a transmission electrical signal TD and generating and outputting a transmission optical signal TX corresponding to the transmission electrical signal TD. The reception function includes, for example, a function of receiving the received optical signal RX and generating and outputting a corresponding received electrical signal RD.

  The optical communication module 100 includes a mounting unit 110 and a controller 120. In the example illustrated in FIG. 1, each element of the optical communication module 100 is provided on the substrate 101. Note that a housing or the like may be used instead of the substrate 101.

  The submodules 200 and 300 are detachably mounted on the mounting unit 110. The mounting part 110 is provided, for example, on the surface on one end side of the substrate 101. The substrate 101 is an adapter substrate on which the submodules 200 and 300 are mounted. In the example illustrated in FIG. 1, the mounting portion 110 is a substantially rectangular region. However, the shape of the mounting part 110 is not limited to this. The submodules 200 and 300 may be fixed to the mounting unit 110. The fixing may be performed using, for example, a fixing member such as a screw (not shown). Further, the submodules 200 and 300 may be fixed to the substrate 101 by an adhesive member or the like. By mounting the submodules 200 and 300 on the mounting portion 110, the power supply lines and signal lines and the like are electrically connected to the substrate 101 and the submodules 200 and 300, respectively. The electrical connection is performed by a method using, for example, an electrical connector, a flexible printed circuit (FPC), soldering, or the like. The substrate 101 and the submodules 200.300 are optically coupled with the transmission paths of the respective optical signals. The optical coupling is performed, for example, by optical coupling using collimated light using an optical lens or the like, coupling of different optical waveguides, or a method using an optical connector.

  The submodule 200 is configured to have a transmission function. The transmission function of the submodule 200 may be a transmission function of one lane (for example, one wavelength in a WDM (Wavelength Division Multiplexing) communication method). In order to realize the multi-lane transmission function, another submodule may be mounted on the mounting unit 110 in addition to the submodule 200. For example, in order to obtain a 4-lane transmission function, in addition to the submodule 200, the submodules 200A, 200B, and 200C may be mounted on the mounting unit 110. The submodules 200, 200A, 200B, and 200C have transmission functions corresponding to different wavelength bands. In order to obtain a transmission function of more lanes (for example, 10 lanes), further submodules are added. One sub-module 200 may have a multi-lane transmission function.

  The submodule 300 is configured to have a reception function. The reception function of the submodule 300 may be a one-lane reception function. In order to realize a multi-lane reception function, in addition to the sub module 300, another sub module may be mounted on the mounting unit 110. For example, in addition to the submodule 300, the submodules 300A, 300B, and 300C may be mounted on the mounting unit 110 in order to obtain a 4-lane reception function. The submodules 300A, 300B, and 300C have reception functions corresponding to different wavelength bands in the WDM communication system, for example. In order to obtain a reception function of more lanes, a further submodule is added. One sub-module 300 may have a function corresponding to a plurality of different wavelength bands, or may have a multi-lane receiving function.

  The controller 120 controls the sub modules 200 and 300. Thereby, control (including transmission and reception of optical signals) and monitoring of the optical communication module 100 are performed. The controller 120 is a microcontroller constituted by, for example, a semiconductor chip. A method of controlling the submodules 200 and 300 by the controller 120 will be described later.

  The optical communication module 100 further includes a connector 130. The connector 130 is a connector for connecting the optical communication module 100 and elements outside the optical communication module 100 (for example, an external circuit or a host computer not shown). For example, a transmission electrical signal TD from an external circuit is input to the optical communication module 100 via the connector 130. The transmission electrical signal TD may include a pair of complementary electrical signals (differential signals). In addition, the received electrical signal RD from the optical communication module 100 is output to an external circuit via the connector 130. The reception electrical signal RD may include a pair of complementary electrical signals (differential signals). Furthermore, communication between the controller 120 and, for example, a host computer is performed via the connector 130. This communication is performed by transmitting and receiving a communication signal SIG via a signal line (second signal line). The communication signal SIG is a communication signal corresponding to various communication methods.

  The optical communication module 100 further includes a port 140. The port 140 is an interface for optical communication. In the example illustrated in FIG. 1, the port 140 includes a transmission port 141 and a reception port 142. The transmission port 141 is a transmission port for outputting the transmission optical signal TX. The reception port 142 is a reception port for receiving the reception optical signal RX. For example, optical connectors for optical communication (not shown) are inserted into the transmission port 141 and the reception port 142. For example, an optical fiber is connected to the optical connector, and an optical signal propagates in the optical fiber.

  Next, the submodule 200 will be further described with reference to FIG. FIG. 2 is a diagram illustrating an example of functional blocks of the submodule 200. As shown in FIGS. 1 and 2, the submodule 200 includes a laser diode 210, a communication ASIC 220, an EEPROM 230, and a connector 240.

  The laser diode 210 is an optical device that generates light upon receiving a current supply (or voltage application). The laser diode 210 is an optical transmission device that generates and transmits a transmission optical signal TX corresponding to the transmission electrical signal TD. The laser diode 210 is configured using, for example, a semiconductor chip. The transmission optical signal TX generated by the laser diode 210 is output toward the transmission port 141.

  Note that the optical device included in the submodule 200 is not limited to the laser diode 210 alone. For example, a PD (Photo Diode) for monitoring the transmission optical signal TX output from the laser diode 210 may be included in the optical device.

  The communication ASIC 220 is a circuit group including a plurality of circuits. The communication ASIC 220 is manufactured, for example, as a single semiconductor integrated circuit in which a plurality of circuits are integrated on one semiconductor chip. The communication ASIC 220 is connected to the laser diode 210 and controls the laser diode 210.

  An example of each circuit configuring the communication ASIC 220 will be described. The communication ASIC 220 includes an ADC 221, an LDD 222, and a DAC 223. However, the circuit included in the communication ASIC 220 is not limited to this.

  The ADC 221 is a circuit for converting an analog quantity into a digital value. For example, the ADC 221 monitors an analog amount such as a current and voltage flowing through the laser diode 210 or a photocurrent output from the above-described monitoring PD, and converts them into a digital value.

  The LDD 222 is a circuit for driving the laser diode 210. For example, the LDD 222 receives the transmission electrical signal TD, generates an electrical signal suitable for driving the laser diode 210, and supplies the electrical signal to the laser diode 210. For example, the LDD 222 supplies a pulsed modulation current to the laser diode 210.

  The DAC 223 is a circuit for converting a digital value into an analog quantity. For example, the DAC 223 supplies an appropriate bias current to the laser diode 210. The communication ASIC 220 supplies a constant bias current and a pulsed modulation current to the laser diode 210 so that the transmission optical signal TX has a predetermined optical average power and extinction ratio. If the required bias current value is larger than the current supply capability of the DAC 223, the DAC 223 does not directly supply the bias current to the laser diode 210, and the DAC 223 is connected to a voltage controlled current source (not shown). A configuration may be adopted in which a sufficient bias current is supplied to the laser diode 210 from a voltage control current source by applying a predetermined control voltage.

  The EEPROM 230 is a storage unit that stores in advance setting information for the submodule 200 to obtain desired characteristics in the combination of the laser diode 210 and the communication ASIC 220. Setting information stored in the EEPROM 230 will be described later.

  The connector 240 is an electrical connector for electrically connecting the submodule 200 and elements outside the submodule 200. For example, the connector 240 has a plurality of terminals, and each terminal can insert (connect) and remove (release) one end of wiring for constituting various electric circuits and signal lines. Each terminal includes, for example, a power supply terminal, a ground (GND) terminal, a high-speed signal line terminal, a communication control terminal, and the like. The power supply terminal is a terminal for supplying power for operating the submodule 200 (for example, power supply voltage and power supply current). The GND terminal is a terminal for supplying a reference potential to the submodule 200. The high-speed signal line terminal is a terminal for supplying the transmission electric signal TD to the submodule 200. The communication control terminal is a terminal for communicating with the outside of the submodule 200 (for example, the controller 120) and the submodule 200 for monitoring and controlling the submodule 200, for example.

  Communication between the controller 120 and the submodule 200 is performed via the connector 240 (its communication control terminal). In particular, communication between the controller 120 and the communication ASIC 220 and the EEPROM 230 in the submodule 200 is performed. This communication is performed by transmitting and receiving a communication signal CS via a signal line (first signal line). The communication signal CS is a communication signal corresponding to various communication methods. Examples of the communication method include serial communication by an I2C (I-squared-C: Inter-Integrated Circuit) method. In that case, the communication signal CS is a communication signal corresponding to I2C. Therefore, in this case, the communication signal CS includes a serial data signal (SDA) and a serial clock signal (SCL). For example, the controller 120 is a master that controls communication, and the communication ASIC 220 and the EEPROM 230 that are communication partners of the controller 120 are slaves that comply with commands from the master. An I2C address is assigned to a slave such as the communication ASIC 220, and the information is stored in the EEPROM 230. The I2C address of the EEPROM 230 is, for example, a predetermined address and is also grasped on the controller 120 side. On the other hand, the I2C address of the communication ASIC 220 or the like is arbitrarily set within a range assigned in advance to the submodule 200 side. First, the controller 120 communicates with the EEPROM 230 and can communicate with the communication ASIC 220 by referring to information stored in the EEPROM 230 (including an I2C address such as the communication ASIC 220). Alternatively, like the EEPROM 230, the I2C address of the communication ASIC 220 may be determined in advance and grasped on the controller 120 side. By doing so, the controller 120 can access the communication ASIC 220 prior to the EEPROM 230. The controller 120 and the elements (such as the LDD 222) included in the communication ASIC 220 can monitor or control the operation state via, for example, an I2C interface circuit or a communication control unit (not shown) included in the communication ASIC 220. . For example, when some parameters related to the LDD 222 are assigned to a predetermined address, the controller 120 specifies an address to the communication ASIC 220 and then reads / writes data stored therein.

  In addition to the submodule 200, when a plurality of submodules such as the submodules 200, 200A, 200B, and 200C are mounted on the mounting unit 110, the controller 120 sets the submodule described above for each submodule. Communication similar to communication with respect to 200 is possible. For example, connecting the controller 120 and the plurality of submodules via one I2C bus and accessing the EEPROM or the communication ASIC in each submodule from the controller 120 is different for each slave. This is possible by assigning addresses.

  The submodule 200 described above is a submodule for optical transmission corresponding to a predetermined transmission wavelength band (for example, one channel in the WDM communication system). The transmission wavelength band includes the peak wavelength of the transmission optical signal TX output from the submodule 200. The submodule 200 is designed to have good optical transmission characteristics in the transmission wavelength band. For this reason, a device having good electrical / optical conversion characteristics in the transmission wavelength band is employed for the laser diode 210. Note that, as a standard for optical communication, for example, the Gigabit Ethernet (registered trademark) standard according to IEEE 802.3ba and the ITU-T recommendation G.264. In order to improve versatility, it is possible to cope with a plurality of different transmission rates defined by these standards in one submodule. Therefore, the optical device is preferably adjusted so that good characteristics can be obtained at each of the plurality of transmission rates.

  The transmission optical signal TX generated by the submodule 200 (the laser diode 210 thereof) is sent to the transmission port 141. When a plurality of submodules 200, 200A, 200B, and 200C are used to adopt a multi-lane transmission configuration, the optical signals generated in the submodules are combined by the optical multiplexer 150 and then transmitted light. The signal TX is sent to the transmission port 141. For example, the optical multiplexer 150 uses a dielectric multilayer filter or AWG (Arrayed Waveguide Gratings). Optical sub-modules 200, 200A, 200B, and 200C and optical multiplexer 150 are connected to the optical path of the optical signal, and the optical path of the optical multiplexer 150 and the transmission port 141 are connected to the optical connector, optical fiber, and single substrate. This is done using the optical waveguide produced above. When optical coupling is achieved by matching the optical axes between the optical paths, alignment is performed as necessary. Note that by mounting the submodule at a predetermined position of the mounting section 110, for example, optical coupling between the optical path of the submodule and the optical path on the substrate 101 may be obtained without alignment.

  An example of the operation of the submodule 200 will be described. First, the transmission electrical signal TD is input to the submodule 200 via the connector 240. Specifically, the transmission electrical signal TD is input to the LDD 222 of the communication ASIC 220. The LDD 222 receives the transmission electrical signal TD, generates a modulation current, for example, and drives the laser diode 210 together with the bias current generated by the DAC 223. As a result, the laser diode 210 generates the transmission optical signal TX. At that time, in the communication ASIC 220, the monitoring result of the laser diode 210 by the ADC 221 (or the monitoring current output from the monitor PD for monitoring the signal intensity of the transmission optical signal TX) is fed back to the LDD 222 and the DAC 223. As a result, the operation of the laser diode 210 is appropriately maintained.

  Here, even if the optical device such as the laser diode 210 is manufactured under the same manufacturing conditions, the characteristics may be different (having individual variations). Therefore, the submodule 200 is designed so as to obtain a desired characteristic even if the laser diode 210 has individual variations. Specifically, the parameters (correction parameters) are adjusted so as to satisfy a predetermined product standard by correcting the driving conditions and the like for individual variations. The correction parameter is adjusted so as to correct individual variations of the laser diode 210. The correction parameter is, for example, a bias current value. Also, a setting parameter is required for the communication ASIC 220 (including the LDD 222 and the like) connected to the laser diode 210 to operate normally. The setting parameters are, for example, a modulation current value, a cross point adjustment value, an input equalizer setting value, and an operation mode setting value. Since circuits such as ADC 221, LDD 222, and DAC 223 of communication ASIC 220 include analog elements, communication ASIC 220 may also have individual variations. In that case, the setting parameters may include parameters for correcting these individual variations.

  The correction parameter and the setting parameter (hereinafter simply referred to as “setting information”) are determined according to the combination of the laser diode 210 and the communication ASIC 220. For example, when a plurality of submodules 200 are produced, setting information is determined for each submodule 200 so that each submodule 200 operates optimally. That is, the setting information is information for the submodule 200 to obtain desired characteristics in the combination of the laser diode 210 and the communication ASIC 220.

  In the present embodiment, the EEPROM 230 is a storage unit that stores in advance the setting information for the submodule 200. The setting information is stored in the EEPROM 230 before the submodule 200 is mounted on the optical communication module 100. For example, in the production process of the submodule 200, the setting information (each parameter) is adjusted, and the adjusted setting information is written in the EEPROM 230. Also, an inspection is performed to confirm that the submodule 200 operates with desired characteristics based on the adjusted setting information.

  As described above, the controller 120 can communicate with the EEPROM 230. Therefore, the controller 120 can read setting information stored in the EEPROM 230 for operating the submodule 200 with desired characteristics. Further, as described above, the controller 120 can also communicate with the communication ASIC 220. Therefore, the controller 120 can set the setting information read from the EEPROM 230 in the communication ASIC 220. The communication ASIC 220 controls the operation of the laser diode 210 according to the setting information set by the controller 120. In this way, the controller 120 can control the elements included in the communication ASIC 220. Specifically, for example, when several parameters related to the LDD 222 are assigned to a predetermined address, the LDD 222 transmits the setting light by designating the address from the controller 120 to the communication ASIC 220 and writing the setting information to the address. The laser diode 210 is driven based on the setting information so as to obtain a desired characteristic of the signal TX. In this case, the LDD 222 is a control device in which setting information is set. In this way, the controller 120 controls the submodule 200, thereby allowing the submodule 200 to operate with desired characteristics. With the same control, even when a plurality of submodules 200, 200A, 200B, 200C, etc. are mounted on the mounting section 110, the controller 120 can operate each submodule with desired characteristics.

  For example, in order for the transmission optical signal TX to be transmitted correctly so as to satisfy a predetermined standard, the LDD 222 must operate appropriately. That is, in this case, the parameters for properly operating the LDD 222 are the setting parameters described above. This setting parameter is written in a memory address assigned to the LDD 222 on a memory (not shown) built in the communication ASIC 220, for example. When the setting parameter is written to the memory address, the LDD 222 operates appropriately.

  Next, the submodule 300 will be further described with reference to FIG. FIG. 3 is a diagram illustrating an example of functional blocks of the submodule 300. As shown in FIGS. 1 and 3, the submodule 300 includes a photodiode 310, a communication ASIC 320, an EEPROM 330, and a connector 340.

  The photodiode 310 is an optical device that receives light and generates electricity (photocurrent). The photodiode 310 is an optical receiving device that receives the received optical signal RX, and is used to generate a received electrical signal RD corresponding to the received optical signal RX. The photodiode 310 is configured using, for example, a semiconductor chip. The received electrical signal RD generated by the photodiode 310 is sent to the connector 130 via a communication ASIC 320 described later. In addition to the photodiode 310, a semiconductor optical amplifier (SOA), a variable optical attenuator, or the like may be used as the optical device. In that case, the received optical signal RX may be input to the SOA or VOA, and the output of the SOA or VOA may be input to the photodiode 310.

  The communication ASIC 320 is a circuit group including a plurality of circuits. The communication ASIC 320 is manufactured, for example, as a single semiconductor integrated circuit in which each circuit is integrated on one semiconductor chip. The communication ASIC 320 is connected to the photodiode 310.

  An example of each circuit constituting the communication ASIC 320 will be described. The communication ASIC 320 includes an ADC 321 and a TIA / LIA 322. However, the circuits included in the communication ASIC 320 are not limited to these.

  The ADC 321 is a circuit for converting an analog quantity into a digital value. For example, the ADC 321 monitors analog quantities such as current and voltage flowing through the photodiode 310 and converts them into digital values.

  The TIA / LIA 322 is a circuit for amplifying the electric signal output from the photodiode 310. The TIA / LIA 322 includes, for example, a TIA (Trans-Impedance Amplifier) or an LIA (Limiting Amplifier).

  The EEPROM 330 is a storage unit that stores in advance setting information for the submodule 300 to obtain desired characteristics in the combination of the photodiode 310 and the communication ASIC 320. Setting information stored in the EEPROM 330 will be described later.

  The connector 340 is an electrical connector for electrically connecting the submodule 300 and elements outside the submodule 300. For example, the connector 340 has a plurality of terminals, and each terminal can insert (connect) and remove (release) one end of wiring for constituting various electric circuits and signal lines. Each terminal includes, for example, a power supply terminal, a GND terminal, a high-speed signal line terminal, a communication control terminal, and the like. The power supply terminal is a terminal for supplying power for operating the submodule 300 (for example, power supply voltage and power supply current). The GND terminal is a terminal for supplying a reference potential to the submodule 300. The high-speed signal line terminal is a terminal for the submodule 300 to output the received electrical signal RD. The communication control terminal is a terminal for performing communication between the outside of the submodule 300 (for example, the controller 120) and the submodule 300 for monitoring and controlling the submodule 300, for example.

  Communication between the controller 120 and the submodule 300 is performed via the connector 340 (its communication control terminal). In particular, communication between the controller 120 and the communication ASIC 320 and the EEPROM 330 in the submodule 300 is performed. This communication is performed using the communication signal CS (for example, an I2C signal) described above. For example, the controller 120 is a master, and the communication ASIC 320 and the EEPROM 330 that are communication partners of the controller 120 are slaves. An I2C address is assigned to the communication ASIC 320 and the like, and the information is stored in the EEPROM 330. The I2C address of the EEPROM 330 is a predetermined address, for example, and is also grasped on the controller 120 side. On the other hand, the I2C address of the communication ASIC 320 or the like is arbitrarily set within a range previously assigned to the submodule 300 side. First, the controller 120 communicates with the EEPROM 330 and can communicate with the communication ASIC 320 by referring to information (including the I2C address of the communication ASIC 320 and the like) stored in the EEPROM 330. Alternatively, like the EEPROM 330, the I2C address of the communication ASIC 320 may be determined in advance and grasped on the controller side. By doing so, the controller 120 can access the communication ASIC 320 prior to the EEPROM 330. The controller 120 and the elements included in the communication ASIC 320 (TIA / LIA 322, etc.) monitor or control the operation state via, for example, an I2C interface circuit or communication control unit (not shown) included in the communication ASIC 320. Can do. For example, when some parameters related to TIA / LIA 322 and the like are assigned to a predetermined address, the controller 120 specifies an address to the communication ASIC 320 and reads / writes data stored therein.

  When a plurality of submodules such as submodules 300, 300A, 300B, and 300C are mounted on the mounting unit 110 in addition to the submodule 300, the controller 120 sets the submodule described above for each submodule. Communication similar to that for 300 is possible. For example, connecting the controller 120 and the plurality of submodules via one I2C bus and accessing the EEPROM or the communication ASIC in each submodule from the controller 120 is different for each slave. This is possible by assigning addresses.

  The submodule 300 described above is a submodule for optical reception corresponding to a predetermined reception wavelength band (one channel in the WDM communication system). The reception wavelength band includes the peak wavelength of the reception optical signal RX received by the submodule 300. The submodule 300 is designed to have good optical reception characteristics in the reception wavelength band. Therefore, a device having good optical / electrical conversion characteristics in the reception wavelength band is employed as the photodiode 310. It should be noted that such a device may be employed when good optical / electrical conversion characteristics can be obtained in each of a plurality of different reception wavelength bands for the required reception performance.

  The received optical signal RX received by the receiving port 142 is sent to the submodule 300. Here, when a plurality of submodules 300, 300 </ b> A, 300 </ b> B, and 300 </ b> C are used to adopt a multi-lane reception configuration, the optical demultiplexer 160 demultiplexes the received optical signal RX received by the reception port 142. Is sent to each submodule. The optical demultiplexer 160 includes, for example, one using a dielectric multilayer filter or AWG (Arrayed Waveguide Gratings).

  An example of the operation of the submodule 300 will be described. First, the received optical signal RX is input to the submodule 300 (via the optical demultiplexer 160 if necessary). Specifically, the received optical signal RX is input to the photodiode 310 of the submodule 300. The photodiode 310 receives the received optical signal RX and generates a photocurrent. The TIA / LIA 322 amplifies the photocurrent. The signal amplified by the TIA / LIA 322 is output to the outside of the submodule 300 via the connector 340 as a received electrical signal RD. At that time, in the communication ASIC 320, the monitoring result of the photocurrent of the photodiode 310 by the ADC 321 is written to a predetermined address of the built-in memory. As a monitoring result of the photocurrent, for example, the photocurrent output from the photodiode 310 is duplicated by an appropriate current mirror circuit, and the average value of the duplicated monitoring current is used. By comparing the monitoring result with a predetermined threshold value, for example, it is possible to provide a function of issuing an alarm signal of loss of received signal (LOS).

  Here, also in the submodule 300, setting information is used as in the submodule 200 described above. Specifically, since an optical device such as the photodiode 310 has individual variations similar to the laser diode 210 described above, an optical input power conversion value, a LOS alarm threshold value, or the like is used. Also for the communication ASIC 320, the identification circuit threshold value, the input equalizer setting value, the output amplitude setting value, and the like are used as in the communication ASIC 220 described above.

  In the present embodiment, the EEPROM 330 is a part that previously stores the setting information regarding the submodule 300. The setting information is stored in the EEPROM 330 before the submodule 300 is mounted on the optical communication module 100. For example, in the production process of the submodule 300, the setting information (each parameter) is adjusted, and the adjusted setting information is written in the EEPROM 330. Also, an inspection is performed to confirm that the submodule 300 operates with desired characteristics based on the adjusted setting information.

  As described above, the controller 120 can communicate with the EEPROM 330. Therefore, the controller 120 can read the setting information stored in the EEPROM 330 for operating the submodule 300 with desired characteristics. Further, as described above, the controller 120 can also communicate with the communication ASIC 320. Therefore, the controller 120 can also set the setting information in the communication ASIC 320. The communication ASIC 320 controls the operation of the photodiode 310 according to the setting information set by the controller 120. In this way, the controller 120 can control the elements included in the communication ASIC 320. Specifically, for example, when the optimum bias voltage value of the photodiode 310 is assigned to a predetermined address, the controller 120 specifies the address to the communication ASIC 320 and writes the setting information to the address. The bias voltage is set by a DAC (not shown) built in the communication ASIC 320 based on the setting information so as to obtain the receiving characteristics. In this case, the DAC built in the communication ASIC 320 is a control device in which setting information is set. In this way, the controller 120 can control the submodule 300, thereby operating the submodule 300 with desired characteristics. With the same control, even when a plurality of submodules 300, 300A, 300B, 300C, etc. are mounted on the mounting section 110, the controller 120 can operate each submodule with desired characteristics.

  For example, in order for the received electrical signal RD generated from the received optical signal RX to satisfy the desired reception characteristics and operate normally, the TIA / LIA 322 must operate properly. In this case, the parameters for properly operating the TIA / LIA 322 are the setting parameters described above. This setting parameter is written to a memory address assigned to the TIA / LIA 322 on a memory (not shown) built in the communication ASIC 320, for example. By writing the setting parameter in the memory address, the TIA / LIA 322 operates appropriately.

  Next, operational effects of the optical communication module 100 will be described. In the optical communication module 100, the submodule 200 includes an optical device such as a laser diode 210 and a communication ASIC 220 that controls the operation of the optical device. The submodule 300 includes an optical device such as the photodiode 310 and a communication ASIC 320 that controls the operation of the optical device. Optical communication is performed by controlling the submodules 200 and 300 by the controller 120.

  Here, the submodule 200 includes an EEPROM 230, and the EEPROM 230 stores in advance setting information necessary for the operation of the laser diode 210 in the combination of the laser diode 210 and the communication ASIC 220. The submodule 300 includes an EEPROM 330, and the EEPROM 330 stores in advance setting information necessary for the operation of the photodiode 310 in the combination of the photodiode 310 and the communication ASIC 320. The controller 120 reads the setting information from the EEPROMs 230 and 330 and sets the setting information in the communication ASICs 220 and 320. The communication ASICs 220 and 320 correspond to the setting information set by the controller 120, and the laser diode 210 and the photodiode 310. By controlling the operation, the submodules 200 and 300 can be operated with desired characteristics. According to the optical communication module 100, adjustment of setting information and inspection after adjustment in a state where the submodules 200 and 300 including optical devices such as the laser diode 210 and the photodiode 310 are mounted on the optical communication module 100 are performed. Is no longer necessary. As a result, the time and cost required for adjustment and inspection can be reduced. In addition, the process for reading the setting information from the EEPROMs 230 and 330 of the submodules 200 and 300 and setting the setting information in the submodules 200 and 300 is realized by the controller 120. For example, to realize such a process It is also possible to eliminate the need to write the software into the submodules 200 and 300.

  The optical communication module 100 further includes a mounting unit 110 to which the submodules 200 and 300 can be attached and detached, and the submodules 200 and 300 are mounted on the mounting unit 110 so as to communicate with the controller 120 via the first signal property. It may be electrically connected. Thereby, it becomes easy to mount the submodules 200 and 300 on the optical communication module 100 and to remove them from the optical communication module 100. Furthermore, electrical connection and release between the submodules 200 and 300 and the controller 120 can be facilitated. For example, even when a failure occurs in the submodules 200 and 300, the submodules 200 and 300 can be easily replaced. Then, since the EEPROMs 230 and 330 included in the replaced submodules 200 and 300 store in advance setting information for the submodules 200 and 300 to obtain desired characteristics, the submodules 200 and 300 need to be updated after replacement. It is not necessary to adjust parameters for correcting individual variations of optical devices such as the laser diode 210 and the photodiode 310 and to perform inspection after the adjustment.

  The controller 120 may be configured to be able to communicate with the outside of the optical communication module 100 (for example, a host computer) via the second signal line. For example, if the controller 120 is adapted to various communication methods, the optical communication module 100 can be incorporated into various external devices and used.

  The optical device in the submodule 200 includes a laser diode 210 (optical transmission device) that transmits a transmission optical signal TX, and the setting information includes a predetermined wavelength band of the transmission optical signal TX (for example, 1 in the WDM communication system). Information for operating with desired transmission characteristics in the channel). Thereby, the submodule 200 can be operated with desired (optimal) transmission characteristics.

  The optical device in the submodule 300 includes a photodiode 310 (optical receiving device) that receives the received optical signal RX, and the setting information indicates that the photodiode 310 has a desired reception characteristic in a predetermined wavelength band (receiving wavelength band). Information for operation may also be included. Thereby, the submodule 300 can be operated with desired reception characteristics.

  A plurality of submodules 200, 200A, 200B, and 200C (and submodules 300, 300A, 300B, 300C, and 300D) corresponding to mutually different wavelength bands are mounted on the mounting unit 110, and the controller 120 receives the first signal. The setting information stored in advance in each EEPROM 230 (and EEPROM 330) of each of the plurality of submodules may be read and the read setting information may be set in each communication ASIC 220 (and communication ASIC 320) via a line. Thereby, a plurality of submodules corresponding to different wavelength bands can be operated with desired characteristics. In this case, for any submodule, adjustment of the setting information and inspection after adjustment in the state where the submodule is mounted on the optical communication module 100 are unnecessary.

  Communication ASICs 220 and 320 may be fabricated as a single semiconductor integrated circuit. As a result, the communication ASICs 220 and 320 can be integrated.

  There are several different standardized platforms in the field of optical communications technology. Examples of such platforms include QSFP (Quad Small Form-factor Pluggable) and CFP (100G Form-factor Pluggable). Each platform has the same optical interface specifications, but the external dimensions and control interface are often different. The optical communication module must be designed so that the external dimensions and the control interface correspond to each platform.

  According to the optical communication module 100 according to the present embodiment, the optical interface specifications can be satisfied by using the same submodules 200 and 300 even on different platforms. The external dimensions and control interface can be dealt with by simply changing the shape and size of the substrate 101, the connector 130, etc., and arranging the program of the controller 120 as necessary. Therefore, according to the optical communication module 100, it is easy to cope with different platforms.

  FIG. 4 is a diagram illustrating an example of a schematic configuration of an optical communication module 100A corresponding to a QSFP platform according to another embodiment of the present invention. The optical communication module 100 </ b> A includes a mounting unit 110 and a controller 120, similar to the optical communication module 100 described above. The submodules 200 and 300 are mounted on the mounting unit 110.

  In the optical communication module 100A, each element of the optical communication module 100A is provided on the substrate 101A. The substrate 101A is a substrate having an external dimension corresponding to the QSFP platform. The optical communication module 100A includes a connector 130A. The connector 130A is a connector having an outer dimension corresponding to the QSFP platform. Communication between the controller 120 and an external element (for example, a host device) of the optical communication module 100A is performed via the connector 130A. This communication is performed using a communication signal SIG1. The communication signal SIG1 is a communication signal of a system corresponding to the QSFP platform. For example, the communication signal SIG1 is a communication signal corresponding to I2C. Thereby, the control interface specification corresponding to QSFP is satisfied. The controller 120 is adjusted to correspond to QSFP by programming or the like.

  According to the optical communication module 100A, the sub-modules 200 and 300 can be used to satisfy the optical interface specifications, and to cope with the external dimensions and control interface of the QSFP.

  On the other hand, FIG. 5 is a diagram illustrating an example of a schematic configuration of an optical communication module 100B corresponding to a CFP platform according to another embodiment of the present invention. Similar to the optical communication module 100 described so far, the optical communication module 100 </ b> B includes a mounting unit 110 and a controller 120. The submodules 200 and 300 are mounted on the mounting unit 110.

  In the optical communication module 100B, each element of the optical communication module 100B is provided on the substrate 101B. The substrate 101B is a substrate having external dimensions corresponding to the CFP platform. The optical communication module 100B includes a connector 130B. The connector 130B is a connector having an external dimension corresponding to the CFP platform. Communication between the controller 120 and an external element (for example, a host device) of the optical communication module 100B is performed via the connector 130B. This communication is performed using a communication signal SIG2. The communication signal SIG2 is a communication signal of a method corresponding to the CFP platform. The communication signal SIG2 is a communication signal corresponding to MDIO, for example. Thereby, the control interface specification corresponding to CFP is satisfied. The controller 120 is adjusted to correspond to the CFP by programming or the like.

  The optical communication module 100B may further include CDRs 170 and 180. The CDR 170 shapes the transmission electric signal TD. The received electrical signal RD is shaped by the CDR 180. Note that the CDRs 170 and 180 may be fabricated in the same semiconductor integrated circuit.

  According to the optical communication module 100B, the sub-modules 200 and 300 can be used to satisfy the optical interface specifications, and to cope with the CFP external dimensions and control interface.

  As can be understood from the examples of the optical communication modules 100A and 100B described above, according to the optical communication module 100 according to the present embodiment, the same submodule 200, 300 can be used. Therefore, according to the optical communication module 100 (FIG. 1), it becomes easy to cope with different platforms.

  As described above with reference to FIGS. 1 to 3, the controller 120 can communicate with the communication ASIC 220 and the communication ASIC 320 using the communication signal CS. The communication signal CS2 is a communication signal corresponding to I2C. In this case, the setting information stored in the EEPROM 230 and the EEPROM 330 may be stored, for example, according to the recording format shown in FIG.

  FIG. 6 is a diagram showing an example of a recording format of setting information stored in the EEPROMs 230 and 330. In the recording format shown in FIG. 6, “header information” is stored in the first storage area, and data D1 to DN are stored in this order in the subsequent storage area. The “header information” includes information such as a format type, a module type, module identification information (serial number), the number of data blocks, and a data block position. The format type indicates the type (type) of the data structure stored in the EEPROM 230 or 330. The module type indicates the type (type) of the submodule mounted inside. The controller 120 can determine whether the correct submodule is used according to the format type and the module type. The module identification information is information for uniquely identifying each submodule and is, for example, a serial number. The controller 120 can identify individual submodules by reading the module identification number. The number of data blocks and the data block position are used, for example, to identify the range and position of data corresponding to a plurality of operating conditions.

  The data D1 includes “data length W1”, “I2C address X1”, “memory address Y1”, and “setting value Z1”. “Data length W1” represents the length of the data D1. “I2C address X1” is an I2C address (I2C address of communication ASICs 220, 320, etc.) of a device capable of I2C communication in the submodule (submodule 200, 300) provided with the EEPROM (EEPROM 230, 330). ). “Memory address Y1” is a memory address that designates a storage area of the I2C device corresponding to “I2C address X1”. For example, in the case of the communication ASIC 220, a location where setting information related to the LDD 222 or the ADC 221 is stored is shown. “Setting value Z1” is the setting information (correction parameter and setting parameter) described above. Since the data D2 to DN are the same as the data D1, description thereof will be omitted.

  According to the recording format shown in FIG. 6, the EEPROMs 230 and 330 specify designated address information for designating the communication partner of the controller 120 (the control device such as the LDD 222 included in the communication ASIC 220 and the DAC included in the communication ASIC 320). (Such as “I2C address X1”), memory address information for setting the setting information in the control device, and setting information are stored in association with each other. The controller 120 reads the contents of the storage area (EEPROMs 230, 330, etc.) and writes the setting information (setting value Z1, etc.) to the memory address of the designated I2C device (device corresponding to the I2C address X1, etc.). By executing the process, it is possible to flexibly cope with various optical communication submodules (submodules 200, 300, etc.). On the submodules 200 and 300 side, different memory addresses and parameters can be freely set for the LDD 222, the TIA / LIA 322, and the like. Further, correction parameters relating to individual variations such as the laser diode 210 and the photodiode 310 can be arbitrarily stored for each individual. Even when a plurality of communication ASICs 220 (or communication ASICs 320) are mounted in the submodule 200 (or the submodule 300) and individual settings are required for each, the recording format shown in FIG. 6 is followed. Setting values for arbitrary I2C addresses and memory addresses can be mixed and stored in the EEPROM 230 (or the EEPROM 330). FIG. 6 shows an example of a recording format when only data D1 to DN is included following the header information. FIG. 7 shows a plurality of data D1 to DN as one aggregate (data block). Shows an example of a recording format when data blocks B1 and B2 are included. The plurality of data blocks store setting information for a plurality of operating conditions, for example, when the ambient temperature of the optical communication module 100 (or 100A, 100B) is 0 ° C., 10 ° C.,. Used when writing to a predetermined storage area (note that only two blocks B1 and B2 are shown in FIG. 7, but in this example, in actuality, 0 ° C to 70 ° is used. 8 blocks up to C are prepared). The controller 120 can grasp the configuration of the data block based on the number of data blocks and the data block position included in the header information, and can write the setting information in a predetermined storage area according to a plurality of operating conditions.

DESCRIPTION OF SYMBOLS 100 ... Optical communication module, 101 ... Board | substrate, 110 ... Mounting part, 120 ... Controller, 130, 240, 340 ... Connector, 140 ... Port, 150 ... Optical multiplexer, 160 ... Optical demultiplexer, 200, 300 ... Submodule , 210... Laser diode (LD), 220, 320... Communication ASIC (circuit group), 230, 330... EEPROM (storage unit), 310.

Claims (8)

An optical device; a circuit group that controls the operation of the optical device; and a storage unit that stores in advance setting information necessary for the operation of the optical device in the combination of the optical device and the circuit group. Module,
A controller capable of communicating via the first signal line with the memory unit and the circuit group;
With
The controller reads the setting information from the storage unit via the first signal line and sets the setting information in the circuit group,
The circuit group controls the operation of the optical device according to the setting information set by the controller.
Optical communication module. The optical communication module further includes a mounting portion to which the submodule can be attached and detached,
The submodule is electrically connected to the controller via the first signal line by being mounted on the mounting portion.
The optical communication module according to claim 1.   The optical communication module according to claim 2, wherein the controller is configured to be able to communicate with the outside of the optical communication module through a second signal line. The optical device includes an optical transmission device that transmits a transmission optical signal,
The optical communication module according to claim 2, wherein the setting information includes information for allowing the optical transmission device to operate with desired transmission characteristics in a predetermined wavelength band of the transmission optical signal. The optical device includes an optical receiving device that receives a received optical signal;
The optical communication module according to claim 2, wherein the setting information includes information for allowing the optical receiving device to operate with desired reception characteristics in a predetermined wavelength band of the received optical signal. A plurality of the submodules corresponding to different wavelength bands are mounted on the mounting portion,
The controller reads the setting information stored in advance in the storage unit of each of the plurality of submodules via the first signal line, and sets the read setting information in each of the circuit groups. The optical communication module according to claim 4 or 5. The circuit group includes a control device in which the setting information is set,
The storage unit includes designation address information for the controller to designate the control device via the first signal line, memory address information for setting the setting information in the control device, and the setting information The optical communication module according to any one of claims 1 to 6, wherein the information is stored in association with each other. The circuit group is manufactured as a single semiconductor integrated circuit.
The optical communication module of any one of Claims 1-7.

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