Optical system and optical network equipment

Abstract

The utility model provides an optical system and optical network equipment, and belongs to the technical field of optical communication. The optical system comprises a plurality of lasers, a laser driving unit and a modulation unit; the working wavelengths of at least two of the plurality of lasers are the same, and the same working wavelength corresponds to one optical port of the optical system; the plurality of lasers are electrically connected with the laser driving unit, the laser driving unit is used for receiving a main and standby selection signal, the main and standby selection signal is used for indicating an optical port currently used by the optical system, and the laser driving unit is further used for driving the laser corresponding to the optical port indicated by the main and standby selection signal to work; the plurality of lasers are also electrically connected with the modulation unit, and the modulation unit is used for modulating light emitted by the working lasers into optical signals carrying information. According to the invention, the internal structure of the ONU can be simplified.

Description

Technical Field

[0001] The present disclosure relates to the field of optical communication technologies, and particularly to an optical system and an optical network device. Background Art

[0002] A passive optical network (PON) is a fiber-based communication technology widely used in scenarios such as fiber to the building (FTTB), fiber to the home (FTTH), and fiber to the room (FTTR). Its core feature is that an optical line terminal (OLT) arranged at the central office establishes an optical communication connection with an optical network unit (ONU) arranged on the user side through an optical distribution network (ODN).

[0003] In large-scale network deployment based on PON technology, redundancy protection is generally used to ensure stable communication between the OLT and the ONU. For example, two ODNs are used to establish communication between the OLT and the ONU. The OLT is connected to the first ODN and the second ODN through optical fibers. The first ODN is connected to the main optical port of the ONU through an optical fiber, and the second ODN is connected to the backup optical port of the ONU through an optical fiber. Then, even if the optical fiber link between the first ODN and the main optical port of the ONU fails, the ONU can still communicate with the OLT through the optical fiber link between the second ODN and the backup optical port of the ONU.

[0004] The main optical port of the ONU corresponds to a set of transceiver systems, and the backup optical port of the ONU corresponds to a set of transceiver systems, resulting in a significant increase in the complexity of the internal circuit of the ONU. Therefore, how to simplify the internal circuit of the ONU is an urgent problem to be solved. Summary of the Utility Model

[0005] The present disclosure provides an optical system and an optical network device that can simplify the structure of the optical system. The optical system is applied in the ONU and can reduce the components in the ONU, thereby simplifying the internal structure of the ONU.

[0006] In a first aspect, the present disclosure provides an optical system, the optical system includes a plurality of lasers, a laser driving unit, and a modulation unit;

[0007] At least two lasers among the plurality of lasers have the same operating wavelength, and the same operating wavelength corresponds to an optical port of the optical system;

[0008] The multiple lasers are all electrically connected to the laser driving unit, which is configured to receive a main / backup selection signal for indicating the optical port currently used by the optical system, and the laser driving unit is further configured to drive the laser corresponding to the optical port indicated by the main / backup selection signal to operate;

[0009] The multiple lasers are also all electrically connected to the modulation unit, which is configured to modulate the light emitted by the operating laser into an optical signal carrying information.

[0010] In the solution shown in the present disclosure, the lasers corresponding to the main optical port and the backup optical port of the multi-optical-port optical system use the same laser driving unit to start operating, and also use the same modulation unit to modulate the emitted light into an optical signal carrying information. Compared with the lasers corresponding to the main optical port and the backup optical port using different laser driving units to start operating and using different modulation units to modulate the emitted light into an optical signal, the optical system of this embodiment is beneficial to reducing the components in the optical system and simplifying the internal structure of the optical system.

[0011] Among them, at least two of the multiple lasers having the same operating wavelength means that at least two of the multiple lasers operate in the same operating mode, and the operating mode of the optical system refers to the transmission rate and bandwidth supported by the optical system in PON network communication. For example, if the optical system includes an operating mode supporting 10GPON network communication (denoted as 10GPON operating mode), then at least two lasers operate in the 10GPON operating mode. Another example is that if the optical system includes an operating mode supporting 50GPON network communication (denoted as 50GPON operating mode), then at least two lasers operate in the 50GPON operating mode.

[0012] In a possible implementation, the optical system includes two optical ports, one of which is used as the main optical port and the other as the backup optical port.

[0013] In the solution shown in the present disclosure, optical fibers are plugged into both the main optical port and the backup optical port. However, the optical fiber connected to the main optical port is connected to the first ODN, and the optical fiber connected to the backup optical port is connected to the second ODN. In this way, even if a fault occurs in the optical fiber link between the first ODN and the main optical port, communication between the OLT and the ONU can still be achieved through the second ODN.

[0014] In a possible implementation, the laser driving unit and the modulation unit are integrated in the same driving chip.

[0015] In the solution shown in the present disclosure, since the laser driving unit is used to provide a DC voltage to the laser to excite the laser to operate, and the modulation unit is used to provide a high-speed AC voltage to the laser to load the transmitted information in the laser emitted by the laser, therefore, both the laser driving unit and the modulation unit input voltage to the laser. Then, the laser driving unit and the modulation unit can be integrated into the same driving chip, and this driving chip can be called an optical physics chip.

[0016] In a possible implementation manner, the laser driving unit includes a plurality of first connection terminals, a second connection terminal, and a first switch;

[0017] The first switch has a plurality of input terminals and a plurality of output terminals. The plurality of first connection terminals are electrically connected to the plurality of input terminals of the first switch one by one. The plurality of output terminals of the first switch are electrically connected to the first poles of the plurality of lasers one by one. The second poles of the plurality of lasers are all electrically connected to the second connection terminal;

[0018] The plurality of first connection terminals are all used to input a DC voltage, the second connection terminal is used to output a DC voltage, and among the plurality of first connection terminals, there are a target connection terminal and non-target connection terminals. The laser electrically connected to the target connection terminal can operate, and the laser electrically connected to the non-target connection terminal cannot operate;

[0019] The first switch is used to receive a main / backup selection signal, and based on the optical port indicated by the main / backup selection signal, control the first pole of the corresponding laser to be electrically connected to the target connection terminal, and control the first poles of other lasers to be electrically connected to the non-target connection terminal.

[0020] In the solution shown in the present disclosure, the voltage applied across the two ends of the laser electrically connected to the target connection terminal is greater than the turn-on voltage of this laser. Therefore, the laser electrically connected to the target connection terminal can operate, that is, can emit light. The voltage applied across the two ends of the laser electrically connected to the non-target connection terminal is less than the turn-on voltage of this laser. Therefore, the laser electrically connected to the non-target connection terminal cannot emit light. Therefore, the first switch can realize that the lasers corresponding to the main optical port and the backup optical port share a laser driving unit to excite and emit light by switching which laser is electrically connected to the target connection terminal.

[0021] In a possible implementation manner, the laser driving unit further includes a third connection terminal and a second switch;

[0022] The third connection terminal is electrically connected to the input terminal of the second switch. The plurality of output terminals of the second switch are electrically connected to the first poles of the plurality of lasers one by one;

[0023] The second switch is configured to receive the main / backup selection signal and control the first pole of the corresponding laser to be electrically connected to the third terminal based on the optical port indicated by the main / backup selection signal;

[0024] When the optical system does not emit an optical signal, the first terminal is used to input a DC voltage, and the third terminal is used to output a DC voltage; when the optical system emits an optical signal, both the first terminal and the third terminal are used to input a DC voltage, and the second terminal is used to output a DC voltage.

[0025] Among them, multiple output terminals of the second switch are electrically connected to the first poles of the multiple lasers one by one. For example, each output terminal of the second switch is electrically connected to the line between the first pole of a laser and an output terminal of the first switch.

[0026] In the solution shown in the present disclosure, when the laser does not need to emit light, the first switch is also in a closed state, and there is current passing through the circuit. When the laser needs to emit light, because there is always current in the circuit where the first switch is located, the current can be quickly delivered to the laser connected to the target terminal, so that the laser can be quickly turned on to emit light. Conversely, the laser can also be quickly turned off.

[0027] In a possible implementation manner, after the second poles of the multiple lasers are connected in sequence, they are connected to the second terminal.

[0028] In the solution shown in the present disclosure, the second pole of the laser can be the cathode of the laser. The connection method in which the cathodes of multiple lasers are connected in sequence and then electrically connected to the second terminal belongs to the common cathode connection. Of course, the cathodes of multiple lasers can also be electrically connected to the second terminal respectively.

[0029] In a possible implementation manner, the second pole of the laser can also be the anode of the laser. The connection method in which the anodes of multiple lasers are connected in sequence and then electrically connected to the second terminal belongs to the common anode connection. Of course, the anodes of multiple lasers can also be electrically connected to the second terminal respectively.

[0030] In a possible implementation manner, after the first poles of the multiple lasers are connected in sequence, they are connected to the modulation unit, and a capacitor is arranged on the line between the first poles of two lasers; after the second poles of the multiple lasers are connected in sequence, they are connected to the modulation unit; the modulation unit is configured to input an AC voltage to the multiple lasers to modulate the light emitted by the working laser into an optical signal carrying information.

[0031] Among them, the first terminal is a DC terminal, and the terminals on the modulation unit are AC terminals. The current between the laser and the first terminal belongs to a DC circuit. The circuit between the laser and the modulation unit belongs to an AC circuit.

[0032] In the solution shown in the present disclosure, since the first poles of multiple lasers are electrically connected to multiple first terminals one by one through first switches, and the first poles of multiple lasers are electrically connected in sequence, in this way, the first poles of all lasers can be electrically connected to the same first terminal. For this reason, a capacitor is arranged on the connection line between the first poles of any two lasers. Based on the characteristic of the capacitor that blocks DC and allows AC to pass through, thus, in the DC circuit, multiple lasers are isolated from each other, and in the AC circuit, multiple lasers are connected in parallel to two terminals of the modulation unit.

[0033] In a possible implementation manner, at least one inductor is arranged on the DC circuit between the first pole of each laser and the laser driving unit, and at least one inductor is arranged on the DC circuit between the second pole of each laser and the laser driving unit.

[0034] In the solution shown in the present disclosure, since the first pole of the laser is electrically connected to both the laser driving unit and the modulation unit, and the second pole of the laser is electrically connected to both the laser driving unit and the modulation unit, the laser driving unit is used to input a DC voltage to the laser, and the modulation unit is used to input an AC voltage to the laser. At least one inductor is arranged on the DC circuit. Based on the characteristic of the inductor that allows DC to pass through and blocks AC, it can block the alternating current from flowing into the DC circuit.

[0035] In a possible implementation manner, the optical system further includes a plurality of detectors and a transimpedance amplifier;

[0036] At least two detectors among the plurality of detectors have the same operating wavelength, and the same operating wavelength corresponds to an optical port of the optical system;

[0037] The transimpedance amplifier includes an output terminal, a plurality of input terminals, and a third switch. The output terminal of the third switch is electrically connected to the output terminal of the transimpedance amplifier. The plurality of input terminals of the third switch are electrically connected to the plurality of input terminals of the transimpedance amplifier one by one. The plurality of input terminals of the transimpedance amplifier are also electrically connected to the plurality of detectors one by one;

[0038] The third switch is used to receive the main / backup selection signal, and based on the optical port indicated by the main / backup selection signal, control the corresponding detector to be electrically connected to the output terminal of the transimpedance amplifier, so that the transimpedance amplifier amplifies and outputs the electrical signal of the detector corresponding to the optical port indicated by the main / backup selection signal.

[0039] In the solution shown in the present disclosure, multiple detectors share one transimpedance amplifier. Compared with using one transimpedance amplifier for each detector, the number of transimpedance amplifiers can be reduced, thereby reducing the electronic components in the optical transceiver system and simplifying the internal structure of the optical transceiver system. The application of this optical transceiver system in an ONU is conducive to simplifying the internal structure of the ONU.

[0040] In a possible implementation manner, the optical system further includes a detector, a transimpedance amplifier, and an optical switch;

[0041] The detector is electrically connected to the transimpedance amplifier. The detector is located on the optical path of the optical switch, and the optical switch is configured to receive the main / backup selection signal and transmit the optical signal input from the optical port indicated by the main / backup selection signal to the detector.

[0042] In the solution shown in the present disclosure, under the action of the optical switch, the detector can receive both the optical signal from the main optical port and the optical signal from the backup optical port. Thus, for the optical system including the main optical port and the backup optical port, there is one detector and one transimpedance amplifier, further reducing the components in the optical system.

[0043] In a second aspect, an optical network device is provided. The optical network device includes a media access control chip and the optical system according to the first aspect or any one of the first aspect. The laser driving unit and the modulation unit of the optical system are both electrically connected to the media access control chip.

[0044] In a third aspect, a transimpedance amplifier is provided. The transimpedance amplifier includes an output end, a third switch, and multiple input ends;

[0045] The transimpedance amplifier includes an output end, multiple input ends, and a third switch. The output end of the third switch is electrically connected to the output end of the transimpedance amplifier. The multiple input ends of the third switch are electrically connected to the multiple input ends of the transimpedance amplifier one by one. The multiple input ends of the transimpedance amplifier are also electrically connected to the multiple detectors one by one;

[0046] The third switch is configured to receive the main / backup selection signal and, based on the optical port indicated by the main / backup selection signal, control the corresponding detector to be electrically connected to the output end of the transimpedance amplifier, so that the transimpedance amplifier amplifies and outputs the electrical signal of the detector corresponding to the optical port indicated by the main / backup selection signal. BRIEF DESCRIPTION OF THE DRAWINGS

[0047] Figure 1 is a schematic diagram of the architecture of passive optical network communication provided by an exemplary embodiment of the present disclosure;

[0048] Figure 2It is a schematic diagram of the architecture of passive optical network communication provided by another exemplary embodiment of the present disclosure;

[0049] Figure 3 It is a schematic diagram of the structure of an optical system provided by an exemplary embodiment of the present disclosure to realize communication between a main optical port and a standby optical port;

[0050] Figure 4 It is a schematic circuit diagram of a laser for transmitting an optical signal through a main optical port and a laser for transmitting an optical signal through a standby optical port, driven by the same laser driving unit and the same modulation unit;

[0051] Figure 5 It is a schematic diagram of the current flowing in the circuit when the optical system provided by an exemplary embodiment of the present disclosure does not emit an optical signal;

[0052] Figure 6 It is a schematic diagram of the current flowing in the circuit when the optical system provided by an exemplary embodiment of the present disclosure emits an optical signal;

[0053] Figure 7 It is a schematic circuit diagram of a detector for transmitting an optical signal through a main optical port and a detector for transmitting an optical signal through a standby optical port, and the electrical signals are amplified by the same transimpedance amplifier;

[0054] Figure 8 It is a schematic diagram of the circuit connection of an optical system provided by an exemplary embodiment of the present disclosure to realize communication between a main optical port and a standby optical port on the transmitting side and the receiving side;

[0055] Figure 9 It is a schematic diagram of an optical system provided by an exemplary embodiment of the present disclosure having a main optical port and a standby optical port to realize multiple working modes;

[0056] Figure 10 It is a schematic diagram of the circuit connection of an optical system provided by an exemplary embodiment of the present disclosure having a main optical port and a standby optical port to realize multiple working modes;

[0057] Figure 11 It is a schematic diagram of the structure of a detector for transmitting an optical signal through a main optical port and a detector for transmitting an optical signal through a standby optical port, and the electrical signals are amplified by the same transimpedance amplifier provided by another exemplary embodiment of the present disclosure;

[0058] Figure 12 It is a schematic diagram of multiple lasers integrated on a silicon wafer provided by an exemplary embodiment of the present disclosure;

[0059] Figure 13 It is a schematic diagram of the structure of an optical transmitter formed by packaging multiple lasers provided by an exemplary embodiment of the present disclosure.

[0060] Description of Reference Numerals

[0061] 1. Laser; 11. First laser; 12. Second laser; 13. Third laser; 14. Fourth laser; 15. Fourth terminal; 16. Fifth terminal; 17. Sixth terminal. 2. Laser driving unit; 21. First terminal; 211. Target terminal; 212. Non-target terminal; 22. Second terminal; 23. Third terminal. 3. Modulation unit. 4. Detector; 41. First detector; 42. Second detector; 43. Third detector; 44. Fourth detector. 5. Transimpedance amplifier. 6. Limiting amplifier. 71. First multiplexer; 72. Second multiplexer. Detailed Embodiment

[0062] This embodiment relates to an optical network device in a passive optical network (PON) system, and particularly to an optical transceiver system within the optical network device.

[0063] As Figure 1 shown, it is a schematic diagram of the PON network communication architecture. Referring to Figure 1 shown, an optical line terminal (OLT) arranged in the central computer room establishes an optical communication connection with an optical network unit (ONU) arranged on the user side through an optical distribution network (ODN). The ODN includes a passive optical splitter for optical power distribution, a backbone optical fiber connected between the passive optical splitter and the OLT, and a branch optical fiber connected between the passive optical splitter and the ONU. When transmitting a downstream signal, the downstream signal sent by the OLT is transmitted to each ONU through the optical splitter, and the ONU selectively receives the downstream data belonging to itself in the downstream signal. When transmitting an upstream signal, the upstream signals sent by multiple ONUs are combined by the optical splitter into one optical signal and transmitted to the OLT.

[0064] In large-scale network deployment based on PON technology, redundancy protection is generally used to ensure stable communication between the OLT and the ONU. Therefore, as Figure 2 shown, it is another schematic diagram of the PON network communication architecture. Referring to Figure 2 shown, the OLT is electrically connected to both the first ODN and the second ODN through optical fibers, and each ONU is electrically connected to the first ODN and the second ODN through optical fibers respectively. For the two optical fibers connected to the ONU, one optical fiber is used as the main optical fiber and is inserted into the main optical port of the ONU, and the other optical fiber is used as the backup optical fiber and is inserted into the backup optical port of the ONU ( Figure 2In [the figure], the optical fiber shown by the solid line can be regarded as the main optical fiber, and the optical fiber shown by the dashed line can be regarded as the standby optical fiber). In this way, even when there is a link failure in the main optical fiber, communication can still be carried out between the ONU and the OLT through the standby optical fiber.

[0065] The main optical port of the ONU needs to correspond to a set of transceiver systems, including a laser, a detector, a laser driver unit, a modulation unit, a transimpedance amplifier, etc. The standby optical port of the ONU also needs to correspond to a set of transceiver systems, including a laser, a detector, a laser driver unit, a modulation unit, a transimpedance amplifier, etc. As a result, there are many internal components in the ONU, and the internal structure is relatively complex.

[0066] For this reason, this embodiment provides an optical system, specifically an optical system with multiple optical ports. Among these multiple optical ports, there are a main optical port and a standby optical port. The lasers corresponding to different optical ports use the same laser driver unit to start working, and also use the same modulation unit to modulate the emitted light into an optical signal carrying information. Compared with the main optical port corresponding to a laser driver unit and a modulation unit, and the standby optical port corresponding to a laser driver unit and a modulation unit, the optical system provided in this embodiment is beneficial to reducing the components in the optical system and simplifying the internal structure of the optical system.

[0067] Among them, the optical system provided in this embodiment can be applied to the multi-port ONU described above, and can also be applied to a multi-port optical network terminal (ONT). This embodiment does not limit the application scenario of the optical system. In the text, it is exemplified by being applied in an ONU.

[0068] Among them, the optical system can be an optical emission system, which only includes the emission side and does not include the reception side. The optical system can also be an optical transceiver system, which not only includes the emission side but also includes the reception side. Below, the characteristics of the optical system will be introduced by taking the optical system applied in the optical transceiver system of the ONU as an example.

[0069] As Figure 3 shown, it is a schematic structural diagram of the optical system. Referring to Figure 3 shown, the optical system includes a laser 1, a laser driver unit 2, and a modulation unit 3. The optical system includes multiple optical ports. For example, it includes two optical ports. One of the optical ports is used as the main optical port, and the other optical port is used as the standby optical port. Optical fibers are inserted into both the main optical port and the standby optical port, and are respectively connected to different ODNs. Of course, the optical system can also include multiple optical ports. One of the optical ports is used as the main optical port and is connected to an OND through an optical fiber. The other optical port is used as the standby optical port and is connected to another ODN through an optical fiber. Another optical port is also used as the standby optical port, but an optical fiber may not be inserted. This embodiment does not limit the number of optical ports included in the optical system. Taking two optical ports as an example, one is used as the main optical port and the other is used as the standby optical port, and optical fibers are inserted into both the main optical port and the standby optical port and are connected to different ODNs.

[0070] Since the operating wavelength of the laser is related to the current operating mode of the ONU. Among them, the operating modes of the ONU can include the operating mode supporting GPON network communication (denoted as GPON operating mode), the operating mode of 10GPON network communication (denoted as 10GPON operating mode), and the operating mode supporting 50GPON network communication (denoted as 50GPON operating mode), etc. For example, the operating wavelength of the laser corresponds one-to-one with the operating mode of the ONU. In the 10GPON operating mode, the operating wavelength of the laser is 1270nm. In the 50GPON operating mode, the operating wavelength of the laser is 1286nm.

[0071] However, the current operating mode of the ONU is determined by the user's selection. Therefore, the current operating mode of the ONU has nothing to do with whether it communicates through the primary optical port or the standby optical port. Then, the operating wavelengths of the lasers communicating through the primary optical port and the lasers communicating through the standby optical port are the same.

[0072] Therefore, in a multi-port optical system with a primary optical port and a standby optical port, the number of lasers 1 is multiple, and at least two of the multiple lasers have the same operating wavelength. In this embodiment, for the convenience of introduction, a dual-port optical system is taken as an example. The optical system includes two optical ports, one as the primary optical port and the other as the standby optical port. Then, the number of lasers is two, which are respectively denoted as the first laser 11 and the second laser 12. For the convenience of introduction, an example is taken where the first laser 11 transmits optical signals outward through the primary optical port, and the second laser 12 transmits optical signals outward through the standby optical port.

[0073] It should be noted that the same operating wavelength of the two lasers described in this embodiment means that the operating modes to which these two lasers belong are the same. Similarly, the different operating wavelengths of the two lasers described in this embodiment mean that the operating modes to which these two lasers belong are different, rather than a slight difference in the operating wavelength caused by error.

[0074] For example, if the operating modes to which two lasers belong are the same, but there is a slight difference in the operating wavelength caused by error, it also belongs to the category of the same operating wavelength described in this embodiment. For example, the operating wavelength of one laser is 1270nm, and the operating wavelength of another laser is 1271nm. These two lasers are both operating in the 10GPON operating mode, then it is considered that their operating wavelengths are the same.

[0075] To simplify the optical system, multiple lasers share a single laser driving unit 2. For example, both poles of multiple lasers are connected to the same laser driving unit 2, and the laser driving unit 2 is used to apply a DC voltage across the two poles of the laser to stimulate the laser to emit light. Therefore, the laser driving unit 2 can also be referred to as a direct current driver.

[0076] Normally, the optical system operates under a single optical port at the same time point. Therefore, referring to Figure 3 as shown, the laser driving unit 2 is internally integrated with a switch. The switch can control the lasers corresponding to the optical ports indicated by the primary / backup selection signal to operate based on the received primary / backup selection signal, and control the other lasers not to operate. Here, a laser operating means the laser emits laser light, and a laser not operating means the laser does not emit laser light.

[0077] For example, the laser driving unit 2 receives the primary / backup selection signal sent by the media access control (MAC) chip of the ONU or externally to the ONU. The primary / backup selection signal is used to indicate the optical port currently used by the optical system. Then, the laser driving unit 2 controls the lasers corresponding to the optical port indicated by the primary / backup selection signal to operate.

[0078] Among them, the primary / backup selection signal can be a level signal. For example, a high level indicates communication using the primary optical port, and a low level indicates communication using the backup optical port. The optical port currently used by the optical system is generally the primary optical port. When a fault occurs in the optical fiber link between the primary optical port and the connected ODN, the optical system will use the backup optical port for communication.

[0079] In this way, the MAC chip or the external device sends the primary / backup selection signal (i.e., high level) to the laser driving unit. After the laser driving unit 2 receives the primary / backup selection signal, it controls the lasers corresponding to the optical port indicated by the primary / backup selection signal to operate, and the other lasers do not operate.

[0080] Furthermore, multiple lasers also share a single modulation unit 3. For example, both poles of multiple lasers are connected to the same modulation unit 3, and the modulation unit 3 is used to apply a high-speed AC signal across the two poles of the multiple lasers to modulate the light emitted by the operating lasers into an optical signal carrying the information to be transmitted. Therefore, the modulation unit 3 can also be referred to as an alternating current driver.

[0081] Similarly, if the optical system is an optical transceiver system, referring to Figure 3As shown, it will also include a detector 4 and a transimpedance amplifier 5. Generally, the operating mode of the optical system and the operating wavelength of the detector (i.e., the wavelength of the light received by the detector) are in one-to-one correspondence. For example, in the 10GPON operating mode, the operating wavelength of the detector is 1577 nm, and in the 50GPON operating mode, the operating wavelength of the detector is 1342 nm.

[0082] As described above, the operating mode in which the ONU is currently located has nothing to do with whether it communicates through the primary optical port or the backup optical port. Therefore, the operating wavelengths of the detector communicating through the primary optical port and the detector communicating through the backup optical port are the same.

[0083] Therefore, in a multi-optical-port optical system, the number of detectors 4 is multiple, and at least two of the multiple detectors have the same operating wavelength. In this embodiment, for the convenience of introduction, two detectors 4 are taken as examples, denoted as the first detector 41 and the second detector 42. Among them, the first detector 41 communicates through the primary optical port, and the second detector 42 communicates through the backup optical port.

[0084] It should be noted that the same operating wavelength of the two detectors described in this embodiment means that the operating modes to which the two detectors belong are the same. If the operating modes to which the two detectors belong are the same, but the operating wavelengths are slightly different due to errors, it also belongs to the category of the same operating wavelength described in this embodiment.

[0085] Similarly, the different operating wavelengths of the two detectors described in this embodiment mean that the operating modes to which the two detectors belong are different, rather than the operating wavelengths being slightly different due to errors.

[0086] Also, since the optical transmitter sub-assembly (TOSA) and the optical receiver sub-assembly (ROSA) in the optical system can be integrated together, it is called a bi-directional optical sub-assembly (BOSA). The laser and the detector in the same operating mode share one optical port to transmit signals. For example, the laser and the detector in the 10GPON operating mode share one optical port to transmit signals, and the laser and the detector in the 50GPON operating mode share one optical port to transmit signals.

[0087] Then, referring to Figure 3As shown, the first laser 11 and the first detector 41 communicate through the same main optical port, and the second laser 12 and the second detector 42 communicate through the same standby optical port. Therefore, for the optical system including the main optical port and the standby optical port, the number of main optical ports can be one, and wavelength division multiplexing technology is adopted to transmit and receive optical signals. The number of standby optical ports is also one, and wavelength division multiplexing technology is adopted to transmit and receive optical signals.

[0088] Therefore, continue to refer to Figure 3 As shown, the optical system further includes a first multiplexer 71 and a second multiplexer 72. The first laser 11 and the first detector 41 are both located on the demultiplexed optical path of the first multiplexer 71, and the multiplexed optical path of the first multiplexer 71 corresponds to the main optical port of the optical system. The second laser 12 and the second detector 42 are both located on the demultiplexed optical path of the second multiplexer 72, and the multiplexed optical path of the second multiplexer 72 corresponds to the standby optical port of the optical system.

[0089] Of course, the optical transmission component and the optical reception component of the optical system can also transmit signals through two optical ports. Then, the number of main optical ports is two, one as the transmitting main optical port and the other as the receiving main optical port. The number of standby optical ports is also two, one as the transmitting standby optical port and the other as the receiving standby optical port. To further simplify the ONU, in this embodiment, as Figure 3 shown, an example where the laser and the detector share one optical port is used.

[0090] To simplify the optical system, multiple detectors share one transimpedance amplifier. For example, the electrical signals output by multiple detectors are all transmitted to the same transimpedance amplifier for electrical signal amplification. Usually, the optical system works under one optical port at the same time point. Therefore, refer to Figure 3 As shown, the transimpedance amplifier 5 integrates a switch inside. The switch can receive the main / standby selection signal and control the detector corresponding to the optical port indicated by the main / standby selection signal to be electrically connected to the output end of the transimpedance amplifier 5, so that the transimpedance amplifier 5 amplifies the electrical signal of the detector corresponding to the optical port indicated by the main / standby selection signal and outputs the amplified electrical signal to the next component (such as a limiting amplifier).

[0091] As can be seen from the above, in the multi-optical-port optical system of this embodiment, the lasers communicating through the main optical port and the lasers communicating through the standby optical port share one laser driver unit 2 and one modulation unit 3. The detectors communicating through the main optical port and the detectors communicating through the standby optical port share one transimpedance amplifier, which can reduce the number of laser driver units 2, the number of modulation units 3, and the number of transimpedance amplifiers, thereby simplifying the circuit inside the optical system.

[0092] In one example, refer to Figure 3As shown, the laser driving unit 2 is used to input a DC voltage to the laser to excite the laser to emit light, while the modulation unit 3 is used to input a high-speed AC voltage to the laser to generate an optical signal carrying information. Therefore, both the laser driving unit 2 and the modulation unit 3 input a driving voltage to the laser. Then, the two can be integrated into a driving chip, which can be denoted as an optical physical (PHY) chip.

[0093] Next, the circuit connection relationship between the laser driving unit 2 and multiple lasers 1, the circuit connection relationship between the modulation unit 3 and multiple lasers 1, and the circuit connection relationship between the transimpedance amplifier and multiple detectors 4 will be introduced.

[0094] For the convenience of explanation, in the following introduction, two optical ports (one main optical port and one standby optical port), two lasers, and two detectors are taken as examples, and it is exemplified that the first laser 11 and the first detector 41 communicate through the main optical port, and the second laser 12 and the second detector 42 communicate through the standby optical port.

[0095] As Figure 4 shown, it is a schematic diagram of the electrical connection between the laser driving unit 2 and the modulation unit 3 and two lasers respectively. Refer to Figure 4 shown, the laser driving unit 2 includes a first terminal 21, a second terminal 22, and a first switch M1. The first switch M1 is specifically a multi-pole multi-throw electronic switch, which has multiple input terminals and multiple output terminals. Refer to Figure 4 shown, multiple input terminals of the first switch M1 are electrically connected to multiple first terminals 21 one by one, multiple output terminals of the first switch M1 are electrically connected to the first poles of multiple lasers one by one, and the second poles of multiple lasers are all electrically connected to the second terminal.

[0096] Among them, the second poles of multiple lasers are all electrically connected to the second terminal 22. For example, refer to Figure 4 shown, after the second poles of multiple lasers are electrically connected in sequence, they are then electrically connected to the second terminal 22. Another example is that the second poles of multiple lasers are respectively electrically connected to the second terminal 22.

[0097] Among them, multiple first terminals are all used to input DC voltage, and the second terminal is used to output DC voltage. Refer to Figure 4 shown, among multiple first terminals 21, there are a target terminal 211 and non-target terminals 212. Among them, any laser electrically connected to the target terminal 211 can work, and any laser electrically connected to the non-target terminals 212 cannot work.

[0098] Among them, the first switch is used to receive the main / backup selection signal, and based on the optical port indicated by the main / backup selection signal, control the first pole of the corresponding laser to be electrically connected to the target terminal, and control the first poles of other lasers to be electrically connected to non-target terminals. Among them, the corresponding laser is the laser that operates under the optical port indicated by the main / backup selection signal, and other lasers are lasers that do not operate under the optical port indicated by the main / backup selection signal.

[0099] Then, in this way, the laser driving unit 2 can control the corresponding laser to operate based on the optical port indicated by the main / backup selection signal, and control the remaining lasers not to operate, so that a single laser driving unit can control the lasers corresponding to multiple optical ports to operate.

[0100] Continue to refer to Figure 4 As shown, the first poles of multiple lasers are also all electrically connected to a terminal of the modulation unit 3, and the second poles of multiple lasers are also all electrically connected to another terminal of the modulation unit 3.

[0101] Take Figure 4 as an example. The first terminal 21 includes a target terminal 211 and a non-target terminal 212. The target terminal 211 is electrically connected to the input terminal a of the first switch M1, the non-target terminal 212 is electrically connected to the input terminal b of the first switch M1, the first pole of the first laser 11 is electrically connected to the output terminal d of the first switch M1, and the first pole of the second laser 12 is electrically connected to the output terminal c of the first switch M1.

[0102] Still take the main / backup selection signal as a level signal. High level indicates using the main optical port for communication, and low level indicates using the backup optical port for communication. For example, the first laser 11 communicates through the main optical port, and the second laser 12 communicates through the backup optical port.

[0103] If the optical port currently used by the optical system is the main optical port, then the main / backup selection signal received by the first switch M1 is high level. When the first switch M1 receives a high level, it controls its input terminal a to be electrically connected to the output terminal d, and the input terminal b to be electrically connected to the output terminal c. At this time, the first laser 11 is electrically connected to the target terminal 211, the first laser 11 emits light, the second laser 12 is electrically connected to the non-target terminal 212, and the second laser 12 does not emit light.

[0104] Continue to refer to Figure 4 As shown, the first poles of the first laser 11 and the second laser 12 are both electrically connected to a terminal of the modulation unit 3, and the second poles of the first laser 11 and the second laser 12 are both electrically connected to another terminal of the modulation unit 3.

[0105] Therefore, at this time, although the modulation unit 3 acts as an AC driver and can apply a high-speed AC voltage across the two lasers, the voltage value of the high-speed AC voltage used to modulate the optical signal is not high. The voltage across the second laser 12 is not sufficient to forward bias it, and may even reverse bias it. Therefore, the impedance of the second laser 12 is very high and it still does not emit light. Since the first laser 11 is electrically connected to the target terminal 211, it can emit light. The voltage applied across the two ends of the first laser 11 is greater than the turn-on voltage (V0). Therefore, the modulation unit 3 can only modulate the transmitted information onto the laser emitted by the first laser 11. Thus, the modulation unit drives multiple lasers in a single path.

[0106] If the optical port currently used by the optical system is the standby optical port, the main / standby selection signal received by the first switch M1 is at a low level. When the first switch M1 receives a low level, it controls its input terminal a to be electrically connected to the output terminal c, and the input terminal b to be electrically connected to the output terminal d. At this time, the second laser 12 is electrically connected to the target terminal 211, and the second laser 12 emits light. The first laser 11 is electrically connected to the non-target terminal 212, and the first laser 11 does not emit light.

[0107] At this time, although the modulation unit 3 acts as an AC driver and can apply a high-speed AC voltage across the two lasers, the voltage value of the high-speed AC voltage used to modulate the optical signal is not high. The voltage across the first laser 11 is not sufficient to forward bias it, and may even reverse bias it. Therefore, the impedance of the first laser 11 is very high and it still does not emit light. Since the second laser 12 is electrically connected to the target terminal 211, the voltage applied across the two ends of the second laser 12 is greater than the turn-on voltage (V0), and it can emit light. Therefore, the modulation unit 3 can only modulate the transmitted information onto the laser emitted by the second laser 12.

[0108] The reason why the laser connected to the target terminal 211 can emit light while the laser connected to the non-target terminal 212 cannot is that the voltage across the laser connected to the target terminal 211 is greater than the turn-on voltage of this laser. Therefore, it can emit light. For the laser connected to the non-target terminal 212, the voltage across it is less than the turn-on voltage of this laser. Therefore, it cannot emit light. For the sake of convenience in introduction, the turn-on voltages of all lasers are considered to be equal, all being V0. Of course, the turn-on voltages of different lasers can also be unequal.

[0109] In order to make the laser connected to the non-target terminal 212 not emit light, it is necessary to satisfy V2 - V3 < V0, where V2 is the voltage value input to the input terminal b of the first switch M1, V3 is the voltage value output from the second terminal 22, and V0 is the turn-on voltage of the laser.

[0110] In order for the laser connected to the target terminal 211 to emit light, it is necessary to satisfy V1 - V3 ≥ V0, where V1 is the voltage value input to the input terminal a of the first switch M1. Among them, V1 > V2.

[0111] In order to satisfy V1 > V2, one implementation is that the voltage input from the target terminal 211 to the input terminal a of the first switch M1 is V1, and the voltage input from the non-target terminal 212 to the input terminal b of the first switch M1 is V2, and V1 > V2. That is to say, the target terminal 211 inputs a relatively high voltage to the input terminal a of the first switch M1, while the non-target terminal 212 inputs a relatively low voltage to the input terminal b of the first switch M1. Thus, V1 - V3 ≥ V0, V2 - V3 < V0.

[0112] Another implementation is that the voltage input from the target terminal 211 to the input terminal a of the first switch M1 is equal to the voltage input from the non-target terminal 212 to the input terminal b of the first switch M1. However, there is a pull-up resistor between the target terminal 211 and the input terminal a of the first switch M1, and the pull-up resistor is connected to a power supply. Then, the voltage V1 input to the input terminal a of the first switch M1 comes from the voltage provided by the target terminal 211 on the one hand and the power supply connected to the pull-up resistor on the other hand. Therefore, the voltage V1 input to the input terminal a of the first switch M1 can be made relatively large. And the voltage input to the input terminal b of the first switch M1 only comes from the voltage provided by the non-target terminal 212. So, the voltage V2 input to the input terminal b of the first switch M1 is relatively small, thus satisfying V1 > V2. Further, V1 - V3 ≥ V0, V2 - V3 < V0.

[0113] As described above, the first poles of multiple lasers are all electrically connected to the modulation unit 3, and the second poles of multiple lasers are all electrically connected to the modulation unit 3. One connection method can be that the first poles of multiple lasers are respectively electrically connected to the modulation unit 3 through a line, and the second poles of multiple lasers are respectively electrically connected to the modulation unit 3 through a line. That is to say, the first poles of multiple lasers are respectively electrically connected to the modulation unit 3, the second poles of multiple lasers are respectively electrically connected to the modulation unit 3, the first poles of multiple lasers are not connected to each other, and the second poles of multiple lasers are not connected to each other.

[0114] In another example, to reduce the wiring layout, the first poles of multiple lasers can be connected in sequence and then electrically connected to the modulation unit 3, and the second poles of multiple lasers can be connected in sequence and then electrically connected to the modulation unit 3. Since the second poles of multiple lasers are connected in sequence and are also connected to the second terminal 22, then, after the second poles of multiple lasers are connected in sequence, they can be both electrically connected to the second terminal 22 and electrically connected to the modulation unit 3. Therefore, referring to Figure 4As shown, after the second poles of the first laser 11 and the second laser 12 are electrically connected, they are respectively connected to the second terminal 22 and the modulation unit 3.

[0115] However, after the first poles of multiple lasers are connected in sequence, all the lasers will be electrically connected to both the target terminal and the non-target terminal. Therefore, a capacitor is arranged on the electrical connection line between the first poles of two connected lasers. Based on the characteristic of the capacitor that blocks direct current and allows alternating current to pass, all the lasers are connected in parallel to the modulation unit 3 in the alternating current circuit, while in the direct current circuit, all the lasers are isolated from each other.

[0116] For example, continue to refer to Figure 4 As shown, after the first poles of the first laser 11 and the second laser 12 are connected, they are electrically connected to a terminal of the modulation unit 3. A capacitor is arranged on the line between the first poles of the first laser 11 and the second laser 12. After the second poles of the first laser 11 and the second laser 12 are connected, they are electrically connected to another terminal of the modulation unit 3.

[0117] In order to prevent the alternating current signal output from the modulation unit 3 from being mixed into the direct current circuit and flowing out through the first terminal 21 or the second terminal 22 in the direct current circuit, an inductor can be arranged in the direct current circuit. Based on the characteristics of the inductor that conducts direct current and blocks alternating current, and conducts low-frequency current and blocks high-frequency current, it can block high-speed alternating current signals from flowing into the direct current circuit.

[0118] For example, referring to Figure 4 As shown, for each laser: at least one inductor is arranged on the line between the electrical connection position of the first pole of the laser and the modulation unit 3 and the electrical connection position of the first pole of the laser and the first switch M1; at least one inductor is arranged on the line between the electrical connection position of the second pole of the laser and the modulation unit 3 and the electrical connection position of the second pole of the laser and the second terminal 22. For example, referring to Figure 4 In, at least one inductor is arranged on the circuit between position A and the output terminal d of the first switch M1, at least one inductor is arranged on the circuit between position B and the output terminal c of the first switch M1, and at least one inductor is arranged on the circuit between position C and the second terminal 22.

[0119] In this way, based on the characteristics of the inductor that conducts direct current and blocks alternating current, and conducts low-frequency current and blocks high-frequency current, it can block the high-speed alternating current signal output from the modulation unit 3 from flowing into the direct current circuit.

[0120] Among them, some components can also be arranged on the electrical connection line between the first pole of each laser and the modulation unit 3, such as one or more of resistors, inductors, and capacitors. On the electrical connection line between the second pole of each laser and the modulation unit 3, some components can also be arranged, such as one or more of resistors, inductors, and capacitors. This embodiment does not limit this, as long as it is ensured that the modulation unit 3 can input a high-speed AC signal to the laser.

[0121] Among them, Figure 4 The multi-throw first switch M1 in can also be replaced by a single-throw multi-throw switch. If the first switch M1 is a single-throw multi-throw switch, the number of the first connection terminals 21 is one, the number of the input terminals of the first switch M1 is one, and the number of the output terminals is equal to the number of lasers.

[0122] In one example, Figure 4 The first pole of the shown laser is the anode, and the second pole of the laser is the cathode. The anodes of multiple lasers are electrically connected to the multiple output terminals of the first switch M1 one by one. The multiple input terminals of the first switch M1 are electrically connected to the multiple first connection terminals 21 one by one. The cathodes of multiple lasers are connected and then connected to the second connection terminal 22. Among them, each first connection terminal 21 is used to input voltage, and the second connection terminal 22 is used to output voltage. This wiring method is called the common cathode wiring method of the laser.

[0123] In another example, it can be the other way around. The first pole of the laser is the cathode, and the second pole of the laser is the anode. The cathodes of multiple lasers are electrically connected to the multiple output terminals of the first switch M1 one by one. The multiple input terminals of the first switch M1 are electrically connected to the multiple first connection terminals 21 one by one. The anodes of multiple lasers are connected and then connected to the second connection terminal 22. Among them, each first connection terminal 21 is used to output voltage, and the second connection terminal is used to input voltage. This wiring method belongs to the common anode wiring method of the laser.

[0124] In the common anode connection of multiple lasers, in order to make the laser electrically connected to the target connection terminal work, it is necessary to satisfy that the voltage output from the target connection terminal is the lowest. Then, a pull-down resistor can be arranged on the line between the target connection terminal 211 and the input terminal a of the first switch M1. The pull-down resistor can be grounded to pull down the voltage at the input terminal a of the first switch M1. The lower the voltage at this point, the greater the voltage applied across the connected laser.

[0125] In another example, in the implementation where the second poles of multiple lasers are all electrically connected to the second terminal, it can also be that the second poles of multiple lasers are respectively electrically connected to the second terminal. Herein, the implementation of electrically connecting the second poles of multiple lasers to the second terminal is not limited in this embodiment. In the drawings, it is schematically shown that after the second poles of multiple lasers are connected in sequence, they are connected to the second terminal.

[0126] In one example, in order to enable the lasers corresponding to the currently used optical ports to be quickly turned on and off, so as to reduce the delay of signal transmission. Accordingly, as Figure 5 shown, it is another electrical connection schematic diagram of the laser driving unit 2 and multiple lasers.

[0127] Referring to Figure 5 shown, the laser driving unit further includes a third terminal 23 and a second switch M2. The second switch M2 is a single-pole multi-throw switch, including one input terminal and multiple output terminals. The input terminal of the second switch M2 is electrically connected to the third terminal 23, and the multiple output terminals of the second switch M2 are electrically connected to the first poles of multiple lasers one by one. For example, each output terminal of the second switch M2 is electrically connected to the line between the first pole of a laser and an output terminal of the first switch M1.

[0128] Taking Figure 5 as an example, an input terminal a of the second switch M2 is electrically connected to the third terminal 23, an output terminal c of the second switch M2 is electrically connected to the line between the first pole of the first laser 11 and the output terminal d of the first switch M1, and an output terminal b of the second switch M2 is electrically connected to the line between the first pole of the second laser 12 and the output terminal c of the first switch M1.

[0129] Among them, the second switch M2 is used to receive the main / backup selection signal, and based on the optical port indicated by the main / backup selection signal, control the first pole of the corresponding laser to be electrically connected to the third terminal.

[0130] When the optical system emits an optical signal, both the target terminal 211 and the third terminal 23 are used to input DC voltage, and the second terminal 22 is used to output DC voltage. When the optical system does not emit an optical signal, the target terminal 211 is used to input DC voltage, while the third terminal 23 is used to output DC voltage.

[0131] Still taking the main / backup selection signal as a level signal, where a high level indicates communication using the main optical port and a low level indicates communication using the backup optical port as an example.

[0132] If the optical port currently used by the optical system is the primary optical port, the main / backup selection signals received by the first switch M1 and the second switch M2 are both high level. When the first switch M1 receives a high level, it controls its input terminal a to be electrically connected to the output terminal d, and the input terminal b to be electrically connected to the output terminal c. At the same time, M2 also receives a high level, controlling its input terminal a to be electrically connected to the output terminal c.

[0133] In the case where the optical system does not emit an optical signal, refer to Figure 5 As shown, the first terminal 21 is used to input a DC voltage, and the third terminal 23 is used to output a voltage. Then, the DC voltage input from the target terminal 211 is directly output outward via the third terminal 23 without passing through the laser connected to the target terminal 211, so the laser does not work.

[0134] In the case where the optical system emits an optical signal, refer to Figure 6 As shown, both the first terminal 21 and the third terminal 23 are used to input a DC voltage, while the second terminal 22 is used to output a DC voltage. Then, the DC voltage input from the target terminal 211 and the DC voltage input from the third terminal 23 are both applied to the laser connected to the target terminal 211, prompting the laser to work.

[0135] Refer to Figure 5 and Figure 6 As shown, when the laser is not required to emit light, the first switch M1 and the second switch M2 are also in the closed state, and there is current flowing through the circuit. When the laser is required to emit light, since there is always current in the circuit where the first switch M1 is located, the current can be quickly delivered to the laser connected to the target terminal 211, enabling the laser to be quickly turned on to emit light. Conversely, the laser can also be quickly turned off.

[0136] Figure 5 and Figure 6 are the circuit characteristics of the laser driving unit 2 and the modulation unit 3 respectively with multiple lasers. Next, the circuit characteristics between the transimpedance amplifier 5 and multiple detectors 4 are introduced.

[0137] The above are the circuit characteristics between the laser driving unit 2, the modulation unit 3 and multiple lasers. Next, the circuit characteristics between the transimpedance amplifier 5 and multiple detectors 4 are introduced.

[0138] As Figure 7 shown, it is a schematic diagram of multiple detectors electrically connected to a single transimpedance amplifier 5. Referring to Figure 7 shown, the transimpedance amplifier 5 includes an output terminal, multiple input terminals, and a third switch M3. The multiple input terminals of the transimpedance amplifier 5 are electrically connected to the multiple detectors 4 one by one. The third switch M3 includes multiple input terminals and an output terminal, and the multiple input terminals of the transimpedance amplifier 5 are also electrically connected to the multiple input terminals of the third switch M3 one by one. The output terminal of the third switch M3 is electrically connected to the output terminal of the transimpedance amplifier 5.

[0139] Among them, the third switch M3 is used to receive the main / backup selection signal, and based on the optical port indicated by the main / backup selection signal, control the corresponding detector to be electrically connected to the output terminal of the transimpedance amplifier 5, so that the transimpedance amplifier 5 amplifies the electrical signal of the detector corresponding to the optical port indicated by the main / backup selection signal and outputs it to the next component (such as a limiting amplifier or a digital signal processor).

[0140] In one example, the receiving side of the optical system may include a limiting amplifier 6, then the output terminal of the transimpedance amplifier 5 is electrically connected to the limiting amplifier 6. The optical system may also include a digital signal processor (DSP), then the output terminal of the limiting amplifier 6 is electrically connected to the DSP, and the output terminal of the DSP is electrically connected to the MAC chip.

[0141] In some other examples, the receiving side of the optical system may only include a limiting amplifier 6, then the output terminal of the transimpedance amplifier 5 is electrically connected to the limiting amplifier 6, and the output terminal of the limiting amplifier 6 is electrically connected to the MAC chip.

[0142] In some other examples, the receiving side of the optical system may also only include a DSP and not include a limiting amplifier 6, then the output terminal of the transimpedance amplifier 5 is electrically connected to the DSP, and the output terminal of the DSP is electrically connected to the MAC chip.

[0143] Among them, this embodiment does not limit what components the transimpedance amplifier 5 includes subsequently, and the example of a limiting amplifier 6 may be included in the drawings.

[0144] Taking Figure 7 as an example, the first detector 41 is electrically connected to the input terminal a of the third switch M3 through an input terminal of the transimpedance amplifier 5, and the second detector 42 is electrically connected to the input terminal b of the third switch M3 through another input terminal of the transimpedance amplifier 5.

[0145] Still taking the main / backup selection signal as a level signal, where high level indicates communication using the main optical port and low level indicates communication using the backup optical port, and the first detector 41 communicates through the main optical port and the second detector 42 communicates through the backup optical port as an example.

[0146] If the optical port currently used by the optical system is the main optical port, the main / backup selection signal received by the third switch M3 is at a high level. When the third switch M3 receives a high level, it controls its output terminal c to be electrically connected to the input terminal a. At this time, the first detector 41 is electrically connected to the output terminal of the transimpedance amplifier 5. The transimpedance amplifier 5 amplifies the electrical signal converted by the first detector 41 and outputs it to the limiting amplifier 6 for further processing.

[0147] If the optical port currently used by the optical system is the backup optical port, the main / backup selection signal received by the third switch M3 is at a low level. When the third switch M3 receives a low level, it controls its output terminal c to be electrically connected to the input terminal b. At this time, the second detector 42 is electrically connected to the output terminal of the transimpedance amplifier 5. The transimpedance amplifier 5 amplifies the electrical signal converted by the second detector 42 and outputs it to the limiting amplifier 6 for further processing.

[0148] Reference Figure 7 As shown, multiple detectors use the same transimpedance amplifier 5 for amplification processing, which can reduce the number of transimpedance amplifiers.

[0149] In an example, not only the third switch M3 but also an amplifier is integrated in the transimpedance amplifier 5. By integrating the third switch M3 into the transimpedance amplifier 5, the electrical connection path between the amplifier and the third switch M3 in the transimpedance amplifier is short, and single-ended wiring can be used to achieve electrical connection to reduce transmission delay.

[0150] Based on the above, taking the example of the MAC chip sending the main / backup selection signal to the laser driving unit 2 and the transimpedance amplifier 5, reference Figure 8 As shown, the laser driving unit 2, the modulation unit 3, and the transimpedance amplifier 5 are all electrically connected to the MAC chip.

[0151] Reference Figure 8 As shown, if the optical port currently used by the optical system is the main optical port, the main / backup selection signals received by the first switch M1, the second switch M2, and the third switch M3 are at a high level. The first switch M1 controls the first laser 11 to be electrically connected to the target terminal 211 and controls the second laser 12 to be electrically connected to the non-target terminal 212. The second switch M2 controls the first laser 11 to be electrically connected to the third terminal 23. The third switch M3 controls the first detector 41 to be electrically connected to the output terminal of the transimpedance amplifier 5.

[0152] Reference Figure 8As shown, if the optical port currently used by the optical system is the standby optical port, the main / standby selection signals received by the first switch M1, the second switch M2, and the third switch M3 are low level. The first switch M1 controls the second laser 12 to be electrically connected to the target terminal 211 and controls the first laser 11 to be electrically connected to the non-target terminal 212. The second switch M2 controls the second laser 12 to be electrically connected to the third terminal 23. The third switch M3 controls the second detector 42 to be electrically connected to the output terminal of the transimpedance amplifier 5.

[0153] Among them, the above is introduced by taking the optical system with dual optical ports as an example. For the optical system with triple optical ports or even more optical ports, the principle is similar to that of the dual-optical-port optical system. It only needs to increase the number of lasers, increase the number of detectors, and increase the channels of the first switch M1, the second switch M2, and the third switch M3. The above dual-optical-port optical system can be referred to.

[0154] In one example, the optical system can also support multiple working modes. Taking the optical system supporting two working modes as an example, they are respectively denoted as the first working mode (such as the 10GPON working mode) and the second working mode (such as the 50GPON working mode). As described above, the working wavelengths of the lasers in different working modes are different, and the working wavelengths of the detectors in different working modes are different. Therefore, referring to Figure 9 As shown, the number of lasers is four, which are respectively denoted as the first laser 11, the second laser 12, the third laser 13, and the fourth laser 14. The first laser 11 and the second laser 12 have the same working wavelength and both work in the first working mode. The first laser 11 communicates through the main optical port, and the second laser 12 communicates through the standby optical port. The third laser 13 and the fourth laser 14 have the same working wavelength and both work in the second working mode. The third laser 13 communicates through the main optical port, and the fourth laser 14 communicates through the standby optical port.

[0155] The number of detectors is four, which are respectively denoted as the first detector 41, the second detector 42, the third detector 43, and the fourth detector 44. The first detector 41 and the second detector 42 have the same working wavelength and both work in the first working mode. The first detector 41 communicates through the main optical port, and the second detector 42 communicates through the standby optical port. The third detector 43 and the fourth detector 44 have the same working wavelength and both work in the second working mode. The third detector 43 communicates through the main optical port, and the fourth detector 44 communicates through the standby optical port.

[0156] Since the lasers and detectors in the same working mode can transmit optical signals through one optical port, therefore, continue to refer to Figure 9As shown, the first laser 11 and the first detector 41, which are both operating in the first working mode, and the third laser 13 and the third detector 43, which are both operating in the second working mode, transmit optical signals through the same main optical port. Then, the first laser 11, the first detector 41, the third laser 13, and the third detector 43 are respectively on the optical splitting paths of the first multiplexer 71, and the combined optical path of the first multiplexer 71 corresponds to the main optical port.

[0157] Similarly, the second laser 12 and the second detector 42, which are operating in the first working mode, and the fourth laser 14 and the fourth detector 44, which are operating in the second working mode, transmit optical signals through the same backup optical port. Then, the second laser 12, the second detector 42, the fourth laser 14, and the fourth detector 44 are respectively on the optical splitting paths of the second multiplexer 72, and the combined optical path of the second multiplexer 72 corresponds to the backup optical port.

[0158] Since the optical system transmits information through one optical port of one optical fiber at a certain time point, the laser driving unit 2 selects one of the four lasers to operate, and the transimpedance amplifier 5 amplifies the electrical signal output by one of the four detectors. In this case, the laser driving unit 2 needs to determine which optical port and which laser operating in which working mode to operate based on both the main / backup selection signal and the mode selection signal. The transimpedance amplifier 5 needs to determine which optical port and which electrical signal output by the detector operating in which working mode to amplify based on both the main / backup selection signal and the mode selection signal.

[0159] Reference Figure 10 As shown, the number of the first connection terminals 21 is four, including one target connection terminal and three non-target connection terminals. The first switch M1 includes four input terminals and four output terminals. The first poles of the four lasers are electrically connected to the four output terminals of the first switch M1 one by one, and the four input terminals of the first switch M1 are electrically connected to the four first connection terminals 21 one by one. The second switch M2 includes one input terminal and four output terminals. The four input terminals of the second switch M2 are electrically connected to the first poles of the four lasers one by one. For example, each input terminal of the second switch M2 is electrically connected to the connection line between the first pole of one laser and the output terminal of the first switch M1. The third switch M3 includes one output terminal and four input terminals. The four input terminals of the third switch M3 are electrically connected to the four detector output terminals one by one.

[0160] If the working mode indicated by the mode selection signal is the first working mode and the optical port indicated by the main / backup selection signal is the main optical port, then the first laser 11 operates, and the other lasers do not operate. The transimpedance amplifier 5 amplifies the electrical signal converted by the first detector 41.

[0161] If the operating mode indicated by the mode selection signal is the first operating mode and the optical port indicated by the primary / backup selection signal is the backup optical port, the second laser 12 operates while the other lasers do not, and the transimpedance amplifier 5 amplifies the electrical signal converted by the second detector 42.

[0162] If the operating mode indicated by the mode selection signal is the second operating mode and the optical port indicated by the primary / backup selection signal is the primary optical port, the third laser 13 operates and the transimpedance amplifier 5 amplifies the electrical signal converted by the third detector 43.

[0163] If the operating mode indicated by the mode selection signal is the second operating mode and the optical port indicated by the primary / backup selection signal is the backup optical port, the fourth laser 14 operates and the transimpedance amplifier 5 amplifies the electrical signal converted by the fourth detector 44.

[0164] In another example, since the operating wavelengths of the detectors for communicating using the primary optical port and the backup optical port are the same, the number of detectors can be one, which can receive optical signals from both the primary optical port and the backup optical port. As Figure 11 shown, the optical system includes a detector 4, a transimpedance amplifier 5, and an optical switch S. Among them, the transimpedance amplifier 5 is different from the above-mentioned transimpedance amplifier. As Figure 11 shown, the transimpedance amplifier integrates an amplifier and does not integrate an electronic switch.

[0165] Refer to Figure 11 shown, both the primary optical port and the backup optical port are on the input optical path of the optical switch S. For example, the optical switch S is a scanning mirror that can rotate based on the received primary / backup selection signal so that the incident optical path corresponds to the primary optical port or the backup optical port. For example, if the optical port indicated by the primary / backup selection signal received by the optical switch S is the primary optical port, the optical switch S rotates until the incident optical path corresponds to the primary optical port; if the optical port indicated by the primary / backup selection signal received by the optical switch S is the backup optical port, the optical switch S rotates until the incident optical path corresponds to the backup optical port.

[0166] Continue to refer to Figure 11 shown, the detector 4 is located on the transmission optical path of the optical switch S, and the detector 4 is electrically connected to the transimpedance amplifier 5. Thus, one detector 4 can select whether to receive optical signals from the primary optical port or the backup optical port through the optical switch S.

[0167] As Figure 11 shown in the scheme, the optical system only needs to include one detector and one transimpedance amplifier, and moreover, the transimpedance amplifier is an ordinary transimpedance amplifier without an integrated electronic switch. Thus, the components of the optical system can be reduced.

[0168] Based on the same idea, the number of lasers can also be one, or a optical switch can be used to transmit the emitted optical signal to the main optical port or the standby optical port.

[0169] The characteristics of the lasers described above are introduced below. In one example, the laser can specifically be a direct modulation laser (DML), or an external modulation laser. The external modulation laser can specifically be an electro-absorption modulated laser (EML) or a Mach-Zehnder Modulator (MZ). The type of the laser is not limited in this embodiment.

[0170] As described above, the number of lasers is multiple. These multiple lasers can be multiple independent semiconductor laser chips, which are then packaged on the same circuit board to form an optical emission component.

[0171] In another example, multiple lasers can be integrated in one semiconductor laser chip. Then, the semiconductor laser chip has multiple resonant cavities, and one resonant cavity serves as one laser. As Figure 12 shown, it is a schematic diagram of two lasers integrated in one semiconductor laser chip. Referring to Figure 12 shown, the semiconductor laser chip has two parallel resonant cavities. One of these two resonant cavities serves as the resonant cavity of the first laser, and the other serves as the resonant cavity of the second laser.

[0172] This solution of integrating multiple lasers in one semiconductor laser chip, that is, the solution of processing lasers with multiple different wavelengths on the same silicon wafer, can significantly reduce costs compared with processing semiconductor laser chips with multiple different wavelengths.

[0173] In one example, whether multiple lasers are integrated in the same semiconductor laser chip or in different semiconductor laser chips, these lasers can be packaged together, that is, packaged on the same circuit board to form a multi-path optical transmitter.

[0174] As Figure 13 shown, it is a structural schematic diagram of the multi-path optical transmitter. Referring to Figure 13 shown, the optical transmitter not only includes Laser 1, but also includes multiple fourth terminals 15, a fifth terminal 16, and a sixth terminal 17. Among them, the fourth terminal 15 is a DC terminal, the fifth terminal 16 is an AC terminal, and the multiple lasers are connected in a common cathode connection mode. Then, the sixth terminal 17 serves as both a DC terminal and an AC terminal.

[0175] Then, referring to Figure 13 as shown, the first poles of the multiple lasers 1 are electrically connected to the multiple fourth terminals 15 one by one, and the fourth terminals 15 are used to be electrically connected to the laser driving unit 2. For example, the multiple fourth terminals 15 are electrically connected to the multiple output terminals of the first switch M1 of the laser driving unit 2 one by one.

[0176] The first poles of the multiple lasers 1 are also all electrically connected to the fifth terminal 16, and the fifth terminal 16 is used to be electrically connected to a terminal of the modulation unit 3.

[0177] The second poles of the multiple lasers are all electrically connected to the sixth terminal 17, and the sixth terminal 17 is used to be respectively electrically connected to the laser driving unit 2 and the modulation unit 3. For example, the sixth terminal 17 is used to be electrically connected to the second terminal 22 of the laser driving unit 2, and the sixth terminal 17 is also used to be electrically connected to another terminal of the modulation unit 3.

[0178] Continuing to refer to Figure 13 as shown, the capacitance on the connection line between the first poles of two adjacent lasers is also integrated in the optical transmitter. The inductor used to isolate the DC circuit and the AC circuit is also integrated in the optical transmitter. For example, for each laser, an inductor is arranged on the line between the electrical connection position between the first pole of the laser and the fifth terminal 16 and the fourth terminal 15 connected to the first pole of the laser.

[0179] In the embodiment of the present disclosure, the lasers corresponding to the main optical port and the backup optical port of the multi-optical-port optical system use the same laser driving unit to start working, and also use the same modulation unit to modulate the emitted light into an optical signal carrying information. Compared with the lasers corresponding to the main optical port and the backup optical port using different laser driving units to start working and using different modulation units to modulate the emitted light into an optical signal, the optical system of this embodiment is beneficial to reducing the components in the optical system and simplifying the internal structure of the optical system.

[0180] This embodiment also provides an optical network device. The optical network device includes a MAC chip and the above-mentioned optical system, and the laser driving unit and the modulation unit of the optical system are both electrically connected to the media access control chip. Among them, the optical network device can specifically be an ONU or an ONT, or can also be an optical module used to be plugged into a device.

[0181] The above are only optional embodiments of the present disclosure, and are not intended to limit the present disclosure. Any modifications, equivalent replacements, improvements, etc. made within the principle of the present disclosure shall be included in the protection scope of the present disclosure.

Claims

1. An optical system, characterized in that: The optical system comprises a plurality of lasers (1), a laser driving unit (2) and a modulation unit (3); At least two lasers (1) among the plurality of lasers (1) have the same operating wavelength, and the same operating wavelength corresponds to an optical port of the optical system; The plurality of lasers (1) are all electrically connected to the laser driving unit (2), the laser driving unit (2) is used to receive a primary / secondary selection signal, the primary / secondary selection signal is used to indicate the optical port currently used by the optical system, and the laser driving unit (2) is also used to drive the laser (1) corresponding to the optical port indicated by the primary / secondary selection signal to operate; The multiple lasers (1) are also electrically connected to the modulation unit (3), and the modulation unit (3) is used to modulate the light emitted by the working lasers (1) into an optical signal carrying information.

2. The optical system according to claim 1, characterized in that The optical system comprises two optical ports, one of which is used as a main optical port and the other is used as a backup optical port.

3. The optical system according to claim 1, characterized in that The laser driving unit (2) and the modulation unit (3) are integrated in the same driving chip.

4. The optical system according to claim 1, characterized in that The laser driving unit (2) comprises a plurality of first wiring terminals (21), a second wiring terminal (22) and a first switch; The first switch has a plurality of input terminals and a plurality of output terminals, the plurality of first terminals (21) are electrically connected one by one to the plurality of input terminals of the first switch, the plurality of output terminals of the first switch are electrically connected one by one to the first poles of the plurality of lasers (1), and the second poles of the plurality of lasers (1) are all electrically connected to the second terminals (22); The plurality of first terminals (21) are all used for inputting a DC voltage, the second terminals (22) are used for outputting a DC voltage, and the plurality of first terminals (21) include a target terminal (211) and a non-target terminal (212), and the laser (1) electrically connected to the target terminal (211) can work, while the laser (1) electrically connected to the non-target terminal (212) cannot work; The first switch is used to receive a master-slave selection signal and, based on the optical port indicated by the master-slave selection signal, control the first pole of the corresponding laser (1) to be electrically connected to the target terminal (211), and control the first poles of other lasers (1) to be electrically connected to the non-target terminal (212).

5. The optical system according to claim 4, characterized in that The laser driving unit (2) further comprises a third wiring terminal (23) and a second switch; The third terminal (23) is electrically connected to the input terminal of the second switch, and the plurality of output terminals of the second switch are electrically connected one by one to the first poles of the plurality of lasers (1); The second switch is used to receive the main standby selection signal and, based on the optical port indicated by the main standby selection signal, control the first pole of the corresponding laser (1) to be electrically connected to the third terminal (23); When the optical system does not transmit an optical signal, the first terminal (21) is used to input a DC voltage, and the third terminal (23) is used to output a DC voltage; when the optical system transmits an optical signal, both the first terminal (21) and the third terminal (23) are used to input a DC voltage, and the second terminal (22) is used to output a DC voltage.

6. The optical system according to claim 1, characterized in that The first electrodes of the plurality of lasers (1) are connected in sequence and then connected to the modulation unit (3), and a capacitor is arranged on the connection line between the first electrodes of two lasers (1); the second electrodes of the plurality of lasers (1) are connected in sequence and then connected to the modulation unit (3); the modulation unit (3) is used to input an alternating current voltage to the plurality of lasers (1) so as to modulate the light emitted by the working lasers (1) into an optical signal carrying information.

7. The optical system according to claim 1, characterized in that: At least one inductor is arranged on the DC circuit between the first pole of each laser (1) and the laser driving unit (2), and at least one inductor is arranged on the DC circuit between the second pole of each laser (1) and the laser driving unit (2).

8. The optical system according to any one of claims 1 to 7, characterized in that: The optical system further comprises a plurality of detectors (4) and a transimpedance amplifier (5); At least two detectors (4) among the plurality of detectors (4) have the same operating wavelength, and the same operating wavelength corresponds to an optical port of the optical system; The transimpedance amplifier (5) comprises an output end, a plurality of input ends and a third switch, the output end of the third switch being electrically connected to the output end of the transimpedance amplifier (5), the plurality of input ends of the third switch being electrically connected one-to-one to the plurality of input ends of the transimpedance amplifier (5), and the plurality of input ends of the transimpedance amplifier (5) being electrically connected one-to-one to the plurality of detectors (4); The third switch is used to receive the primary / standby selection signal, and based on the optical port indicated by the primary / standby selection signal, controls the corresponding detector (4), and is electrically connected to the output end of the transimpedance amplifier (5), so that the transimpedance amplifier (5) amplifies and outputs the electrical signal of the detector (4) corresponding to the optical port indicated by the primary / standby selection signal.

9. The optical system according to any one of claims 1 to 7, characterized in that: The optical system also includes a detector (4), a transimpedance amplifier (5) and an optical switch; The detector (4) is electrically connected to the transimpedance amplifier (5); the detector (4) is located on the optical path of the optical switch; the optical switch is used to receive the primary / standby selection signal and transmit the optical signal input from the optical port indicated by the primary / standby selection signal to the detector (4).

10. An optical network device, characterized in that: The optical network device comprises a media access control chip and the optical system according to any one of claims 1 to 9, wherein the laser driving unit and the modulation unit of the optical system are both electrically connected to the media access control chip.

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