Coherent burst receiving local oscillator laser output power adjustment device, equipment and method

Abstract

The present invention discloses a coherent burst receiving local oscillator laser output power adjustment device, equipment and method, which relate to the field of coherent optical communication technology. The device includes a burst coherent receiving component, which is used to complete the photoelectric conversion and amplify the electrical signal; the burst processing control unit is internally provided with a power high and low threshold value and a power and LO bias current relationship table, which is used to perform deviation correction and compare the optical power after the deviation correction signal light and the local oscillator light are mixed with the power high and low threshold value, and output a power control signal based on the comparison result and the power and LO bias current relationship table; the local oscillator laser and its control unit adjust the output optical power according to the power control signal. The present invention can dynamically adjust the LO laser power so that the OLT dynamically adjusts the received optical power within the threshold range according to the intensity of the received optical signal, so as to ensure that the signals of all ONUs can be completely restored, meeting the needs of applying coherent technology to the field of optical access networks.

Description

Technical Field

[0001] The present invention relates to the technical field of coherent optical communications, and in particular to a device, equipment and method for adjusting the output power of a coherent burst receiving local oscillator laser. Background Art

[0002] Coherent transmission has been widely used in point-to-point transmission and data centers. At the coherent receiving end, the signal light is mixed with the local oscillator (LO) and then output to the diode for photoelectric conversion. Since the coherent transmission and data center applications are point-to-point systems, the signal light power received by the receiving end remains basically unchanged. Therefore, the LO output light power can remain unchanged to ensure normal signal reception. Figure 1 shown.

[0003] In the optical access network sector, coherent technology is the preferred approach as 50G TDM-PON evolves to 100G and higher-speed PON. When coherent technology is applied to TDM-PON systems, the optical line terminal (OLT) receiving side receives optical signals from different optical network units (ONUs) at different times using time-division multiple access (TDMA). Due to factors such as the distance between each ONU and the differences in branch links, the power of the optical signals received by the OLT will vary. If the OLT receiving end lacks the ability to quickly process sudden changes in optical power, optical signals from ONUs that are farther or closer, or with greater or lesser optical power attenuation, will be incorrectly restored when they reach the OLT due to optical power levels that are lower or higher than the threshold (signals are considered valid only if they are within the threshold range; signals below or above the threshold cannot be correctly restored).

[0004] Therefore, if coherent technology is to be applied to the field of optical access networks, it is urgent to solve the problem of adjusting the output optical power of the local oscillator laser LO under coherent burst reception on the OLT side to ensure that the signals of all ONUs can be fully restored. Summary of the Invention

[0005] The purpose of the present invention is to overcome the shortcomings of the above-mentioned background technology and provide a coherent burst receiving local oscillator laser output power adjustment device, equipment and method. By dynamically adjusting the LO laser power, the OLT can dynamically adjust the received light power within the threshold range according to the intensity of the received light signal to ensure that the signals of all ONUs can be fully restored, meeting the needs of applying coherent technology to the field of optical access networks.

[0006] To achieve the above objectives, in a first aspect, an embodiment of the present invention provides a coherent burst receiving local oscillator laser output power adjustment device, comprising:

[0007] A burst coherent receiving component is used to: complete the photoelectric conversion and amplify the electrical signal, and output the signal data to the burst processing control unit;

[0008] A burst processing control unit, which is internally provided with power high and low thresholds and a table of power and LO bias current relationships, is used to correct the frequency offset of the local oscillator laser; compare the optical power of the corrected signal light and the local oscillator light after mixing with the power high and low thresholds, and output a corresponding power control signal to the local oscillator laser and its control unit based on the comparison result and the power and LO bias current relationship table;

[0009] A local oscillator laser and a control unit thereof are used to adjust the output optical power according to a received power control signal.

[0010] In combination with the first aspect, in one embodiment, the burst processing control unit corrects the frequency offset of the local oscillator laser, including:

[0011] The burst processing control unit detects the initial frequency f of the local oscillator laser Lo The signal frequency f of the ONU burst signal light s Frequency deviation Δf, Δf=f s -f Lo ;

[0012] If the positive bias Δf>+Δf0, Δf0 is the normal frequency range agreed by the system, then the positive bias frequency adjustment control signal is output to the local oscillator laser control unit, so that it adjusts the local oscillator laser frequency toward the high frequency direction until Δf is within Δf0;

[0013] If the negative bias Δf is less than -Δf0, a negative bias frequency adjustment control signal is output to the local oscillator laser control unit to adjust the local oscillator laser frequency toward a low frequency until Δf is within Δf0.

[0014] In conjunction with the first aspect, in one embodiment, the burst processing control unit compares the optical power of the corrected signal light and the local oscillator light after mixing with the high and low power thresholds, and outputs a corresponding power control signal to the local oscillator laser and its control unit based on the comparison result and in combination with a power and LO bias current relationship table, including:

[0015] The burst processing control unit detects the optical power of the corrected signal light and the mixed local oscillator light, and compares it with the high and low power thresholds;

[0016] If the power is greater than the high power threshold, a power adjustment control signal for reducing the power is output to the local oscillator laser control unit according to the power and LO bias current mapping table;

[0017] If the power is less than the low power threshold, a power adjustment control signal for increasing the power is output to the local oscillator laser control unit according to the power and LO bias current mapping table.

[0018] In combination with the first aspect, in one embodiment, the burst processing control unit is further used to: determine whether the adjusted optical power is within the high and low power thresholds; if so, control the local oscillator laser to output the adjusted power and end the adjustment; otherwise, repeat the adjustment until the adjusted optical power is within the high and low power thresholds.

[0019] In combination with the first aspect, in one implementation, the burst coherent receiving component includes:

[0020] The first device is used to: complete polarization splitting of the signal light and the local oscillator laser light signal;

[0021] The second device is used to: complete the mixing output of the optical signal;

[0022] The third device is used to: complete photoelectric conversion and output current;

[0023] The fourth device is used to convert the current into a voltage signal and amplify the voltage signal and output it to the burst processing control unit.

[0024] In combination with the first aspect, in one embodiment, the first device includes a polarization beam splitter; the second device includes a 90° mixer or a 2×2 coupler; the third device includes a balanced diode or a single diode; and the fourth device includes a transimpedance amplifier.

[0025] In combination with the first aspect, in one embodiment, if the receiving end adopts a dual-polarization receiving mode, the first device of the burst coherent receiving component is a polarization beam splitter, the second device is a 90° mixer, the third device is a balanced diode, and the fourth device is a transimpedance amplifier.

[0026] In combination with the first aspect, in one embodiment, if the receiving end adopts a single polarization receiving mode, the burst coherent receiving component omits the first device, and the second device is a 2×2 coupler, the third device is a balanced diode, and the fourth device is a transimpedance amplifier.

[0027] In combination with the first aspect, in one embodiment, if the receiving end is a single-polarization minimalist receiving mode, the burst coherent receiving component omits the first device, and the second device is a 2×2 coupler, the third device is a single diode, and the fourth device is a transimpedance amplifier.

[0028] In a second aspect, an embodiment of the present invention further provides an OLT device, in which the coherent burst receiving local oscillator laser output power adjustment device according to the embodiment of the first aspect is provided.

[0029] In a third aspect, an embodiment of the present invention further provides a method for adjusting the output power of a coherent burst receiving local oscillator laser based on the device in the embodiment of the first aspect, the method comprising the following steps:

[0030] The burst coherent receiving component receives the burst signal light from different ONUs and the light output by the local oscillator laser, completes the photoelectric conversion and outputs the amplified electrical signal to the burst processing control unit;

[0031] The burst processing control unit corrects the frequency offset of the local oscillator laser and compares the optical power of the corrected signal light and the mixed local oscillator light with the built-in power high and low thresholds. Based on the comparison result and the built-in power and LO bias current relationship table, it outputs the corresponding power control signal to the local oscillator laser and its control unit.

[0032] The local oscillator laser and its control unit adjust the output optical power according to the received power control signal.

[0033] The beneficial effects of the technical solutions provided in the embodiments of the present application include:

[0034] The embodiments of the present application achieve the ability to adjust the output optical power of the local oscillator laser during coherent burst reception, thereby increasing the dynamic range of coherent burst reception, thereby solving the problem of bit errors caused by different received signal light sizes when the OLT burst reception and the output optical power of the OLT local oscillator laser are fixed in the prior art, and meeting the needs of applying coherent technology to the field of optical access networks. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Figure 1 The following is a block diagram of an existing point-to-point coherent receiving system;

[0036] Figure 2 This is a block diagram of an existing burst coherent receiving system;

[0037] Figure 3 This is a functional module diagram of the first embodiment of the coherent burst receiving local oscillator laser output power adjustment device of the present application;

[0038] Figure 4 Schematic diagram of the relationship between LO frequency and optical power after mixing;

[0039] Figure 5 This is a diagram showing the relationship between the received power and bit error rate of a burst coherent receiving component;

[0040] Figure 6Schematic diagram of the functional modules of the burst coherent receiving component in an embodiment of the present application;

[0041] Figure 7 This is a flow chart of the first embodiment of the method for adjusting the output power of a local oscillator laser for coherent burst reception according to the present application;

[0042] Figure 8 Schematic diagram of a device for adjusting the output power of a local oscillator laser for coherent burst reception based on dual-polarization reception in an example;

[0043] Figure 9 The figure is a flow chart of a method for adjusting the output power of a local oscillator laser for coherent burst reception based on dual-polarization reception in an example. DETAILED DESCRIPTION

[0044] First, the design concept of the present invention is further explained: the present invention is intended to solve the problem that the output power of the local oscillator laser LO needs to be adjusted during coherent burst reception on the OLT side to ensure that the signals of all ONUs can be fully restored.

[0045] Specifically, when coherent technology is applied to the field of optical access networks, especially in point-to-multipoint coherent PON systems, the optical power received by the OLT from different ONUs will be different because the OLT receiving side will receive optical signals from different ONUs, and the distances between the ONUs and the OLT are different, and the link conditions are different. Figure 2 As shown, an ICR (Integrated Coherent Receiver) equipped with a TIA (Trans-Impedance Amplifier) ​​receives burst signals from different ONUs, each with varying optical powers. If the OLT-side LO output optical power is constant, the output signal will be smaller after coherence with an ONU receiving lower optical power, falling below the lower threshold and causing line errors (i.e., recovering an erroneous signal). Conversely, if the output signal is coherent with an ONU receiving higher optical power, it will be too large, exceeding the upper threshold and causing line errors (i.e., recovering an erroneous signal). These situations will affect normal communication, thus failing to meet the requirements for coherent technology applications in optical access networks.

[0046] To solve the above problems, the present invention proposes a solution: a coherent burst receiving local oscillator laser output power adjustment device is designed on the OLT side. The burst coherent receiving component in the device receives burst signal light from different ONUs and the light output by the local oscillator laser, completes the photoelectric conversion, and outputs the amplified electrical signal to the burst processing control unit; the burst processing control unit is then used to correct the frequency offset of the local oscillator laser; and the optical power after mixing the corrected signal light and the local oscillator light is compared with the built-in power high and low threshold values. Based on the comparison result and in combination with the built-in power and LO bias current relationship table, a corresponding power control signal is output to the local oscillator laser and its control unit; finally, the local oscillator laser and its control unit can adjust the output optical power according to the received power control signal.

[0047] In this solution, the laser power of the LO in the OLT can be dynamically adjusted so that the OLT can dynamically adjust the received optical power within the threshold range according to the intensity of the received optical signal to ensure that the signals of all ONUs can be fully restored, meeting the needs of applying coherent technology to the field of optical access networks.

[0048] In order to enable those skilled in the art to better understand the present invention, the following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0049] In order to make the objectives, technical solutions and advantages of this application clearer, the implementation methods of this application will be further described in detail below with reference to the accompanying drawings.

[0050] In a first aspect, an embodiment of the present application provides a coherent burst receiving local oscillator laser output power adjustment device.

[0051] In one embodiment, referring to Figure 3 As shown, Figure 3 This is a functional module diagram of the first embodiment of the coherent burst receiving local oscillator laser output power adjustment device of this application. Figure 3 As shown, a coherent burst receiving local oscillator laser output power adjustment device is provided in a burst coherent receiving end (such as an OLT device), comprising:

[0052] The burst coherent receiving component is used to complete the photoelectric conversion and amplify the electrical signal, and output the signal data to the burst processing control unit.

[0053] The burst processing control unit is internally provided with power high and low thresholds and a table of power and LO bias current relationships, which is used to: correct the frequency offset of the local oscillator laser; and compare the optical power of the corrected signal light and the local oscillator light after mixing with the power high and low thresholds, and output the corresponding power control signal to the local oscillator laser and its control unit based on the comparison result and the table of power and LO bias current relationships, so as to complete the adjustment and control of the output optical power of the local oscillator laser. It can be understood that, if Figure 3 As shown, the burst processing control unit, while completing the adjustment and control of the output optical power of the local oscillator laser, will also send the processed signal data to the subsequent PON MAC protocol unit for data transmission. In actual applications, the power high and low threshold values ​​and the power and LO bias current relationship table can be pre-built into the burst processing control unit, but later according to the specific usage, they can still be adjusted and set accordingly through the device's external chip communication interface (such as SPI, MDIO, etc.). Among them, the power high and low threshold values ​​include a high power threshold value and a low power threshold value; within the high power threshold value and the low power threshold value, the signal is normal, the signal has no bit errors or the signal bit error rate can be corrected to no bit errors through the forward error correction method of the PONMAC protocol unit; if the power exceeds the high power threshold value or is lower than the low power threshold value, the signal is abnormal, which will result in a system bit error rate BER1, which cannot be corrected to no bit errors through subsequent error correction methods, and the system cannot work normally.

[0054] A local oscillator laser and a control unit thereof are used to adjust the output optical power according to a received power control signal.

[0055] It is understandable that since the local oscillator laser needs to lock the frequency to the signal frequency, any deviation will affect the output optical power after mixing, such as Figure 4 As shown, in this embodiment, a frequency error processing function is designed in the burst processing control unit, that is, the burst processing control unit will first determine the frequency offset of the local oscillator laser and correct the frequency offset, thereby controlling the frequency offset (frequency error) within the system requirement range. In addition, the setting of the high and low power thresholds is because the transimpedance amplifier in the burst coherent receiving component has a linear amplification area. Within the threshold, it is in the linear area and the system can work normally. If the received electrical signal is too high or too low, it will exceed the linear area, resulting in system errors and malfunction. Figure 5As shown. Therefore, in order to prevent the signal from entering the nonlinear region, the burst processing control unit in this embodiment will compare the optical power after the signal light after deviation correction and the mixing of the local oscillator light with the high and low power thresholds, and output the corresponding power control signal based on the comparison result and the relationship table between power and LO bias current, so as to control and adjust the output power of the local oscillator laser. It is also based on the above functional design that the device of this embodiment can use the burst processing control unit to dynamically adjust the LO laser power so that the OLT can dynamically adjust the received light power within the threshold value (threshold) according to the intensity of the received light signal, so as to ensure that the signals of all ONUs can be fully restored without bit errors, thereby meeting the needs of applying coherent technology to the field of optical access networks.

[0056] Furthermore, as an optional implementation manner, in this embodiment, the burst processing control unit corrects the frequency offset of the local oscillator laser, specifically including:

[0057] 1. The burst processing control unit detects the initial frequency f of the local oscillator laser Lo The signal frequency f of the ONU burst signal light s Frequency deviation Δf, Δf=f s -f Lo ; Among them, the initial frequency f of the local oscillator laser Lo It is pre-built into the local oscillator laser and its control unit, and the burst processing control unit can obtain the corresponding information from it and save it; generally speaking, the initial frequency f Lo No adjustment is required in the later stage, but in specific applications, you can still make corresponding adjustments and settings based on actual needs through the device's external chip communication interface (such as SPI, MDIO, etc.);

[0058] 2. If the positive deviation Δf>+Δf0, and Δf0 is the normal frequency range agreed upon by the system, the burst processing control unit outputs a positive frequency adjustment control signal to the local oscillator laser control unit, causing it to adjust the local oscillator laser frequency toward high frequency until the frequency deviation Δf is within the normal frequency range Δf0 agreed upon by the system. Currently, the normal frequency range Δf0 agreed upon by the system is usually 100 MHz.

[0059] 3. If the negative deviation Δf is less than -Δf0, the burst processing control unit outputs a negative-bias frequency adjustment control signal to the local oscillator laser control unit, causing it to adjust the local oscillator laser frequency toward the low frequency direction until the frequency deviation Δf is within the normal frequency range Δf0 agreed by the system.

[0060] Furthermore, as an optional implementation, in this embodiment, the burst processing control unit compares the optical power after the corrected signal light and the mixing of the local oscillator light with the high and low power thresholds, and outputs a corresponding power control signal to the local oscillator laser and its control unit based on the comparison result and in combination with the power and LO bias current relationship table, specifically including:

[0061] 1. The burst processing control unit detects the optical power of the corrected signal light and the mixed local oscillator light, and compares it with the high and low power thresholds.

[0062] 2. If the power is greater than the high threshold, the power adjustment control signal is output to the local oscillator laser control unit according to the power and LO bias current mapping table, so that it reduces the output optical power of the local oscillator laser. The step size of the reduction is determined according to the actual system.

[0063] 3. If the power is less than the low threshold, the power adjustment control signal is output to the local oscillator laser control unit according to the power and LO bias current mapping table, so that it increases the output optical power of the local oscillator laser. The step size of the increase is determined according to the actual system.

[0064] It is understandable that since the step size of each adjustment is determined based on the actual system, it is possible that a single adjustment may not bring the output optical power of the local oscillator laser within the power threshold. Therefore, to ensure the effectiveness of the adjustment, in actual applications, the burst processing control unit is further configured to: determine whether the adjusted optical power is within the upper and lower power thresholds; if so, control the local oscillator laser to output the adjusted power and terminate the current adjustment; otherwise, repeat the adjustment (i.e., repeat steps 1 to 3 above) until the adjusted optical power is within the upper and lower power thresholds.

[0065] Further, refer to Figure 6 As shown, as an optional implementation manner, in this embodiment, the burst coherent receiving component includes:

[0066] The first device is used to: complete polarization splitting of the signal light and the local oscillator laser light signal;

[0067] The second device is used to: complete the mixing output of the optical signal;

[0068] The third device is used to: complete photoelectric conversion and output current;

[0069] The fourth device is used to convert the current into a voltage signal and amplify the voltage signal and output it to the burst processing control unit.

[0070] The first device may be a polarization beam splitter; the second device may be a 90° mixer or a 2×2 coupler; the third device may be a balanced diode or a single diode; and the fourth device may be a transimpedance amplifier. It is understood that in practical applications, the specific composition of the burst coherent receiving component may vary due to the different receiving modes of the coherent system receiver (such as single polarization receiving mode, dual polarization receiving mode, or simplified coherent receiving mode).

[0071] Exemplarily, if the receiving end uses a dual-polarization receiving mode, the first component is a polarization beam splitter, the second component is a 90° mixer, the third component is a balanced diode, and the fourth component is a transimpedance amplifier. If the receiving end uses a single-polarization receiving mode, the first component can be omitted from the burst coherent receiving component, and the second component is a 2×2 coupler, the third component is a balanced diode, and the fourth component is a transimpedance amplifier. If the receiving end uses a single-polarization minimalist receiving mode, the first component can be omitted from the burst coherent receiving component, and the second component is a 2×2 coupler, the third component is a single diode, and the fourth component is a transimpedance amplifier.

[0072] It can be seen that the device of this embodiment can be used to apply different receiving schemes according to system requirements, has a wide range of applications and is flexible to use, and meets actual application needs.

[0073] In a second aspect, embodiments of the present application provide an OLT device, which incorporates the coherent burst receive local oscillator laser output power adjustment device of the first aspect. The OLT device utilizes the internal adjustment device to dynamically adjust the LO laser power, ensuring that the received optical power remains within a threshold range based on the strength of the received optical signal. This ensures that all ONU signals can be fully restored, meeting the requirements for the application of coherent technology in optical access networks.

[0074] In a third aspect, an embodiment of the present application provides a method for adjusting the output power of a coherent burst receiving local oscillator laser based on the device in the embodiment of the first aspect.

[0075] In one embodiment, referring to Figure 7 As shown, Figure 7 This is a flow chart of the first embodiment of the method for adjusting the output power of the local oscillator laser for coherent burst reception of this application. Figure 7 As shown, a method for adjusting the output power of a coherent burst receiving local oscillator laser includes:

[0076] Step A: The burst coherent receiving component receives the burst signal light from different ONUs and the light output by the local oscillator laser, completes the photoelectric conversion and outputs the amplified electrical signal to the burst processing control unit;

[0077] Step B: The burst processing control unit corrects the frequency offset of the local oscillator laser; compares the optical power of the corrected signal light and the local oscillator light after mixing with the built-in power high and low thresholds, and outputs a corresponding power control signal to the local oscillator laser and its control unit based on the comparison result and the built-in power and LO bias current relationship table;

[0078] Step C: The local oscillator laser and its control unit adjust the output optical power according to the received power control signal.

[0079] It should be noted that the various variations and specific examples described in the above-mentioned device embodiment are also applicable to the method of this embodiment. Through the detailed description of the above-mentioned device, those skilled in the art can clearly know the various implementation methods of the method in this embodiment, so for the sake of brevity of the specification, they will not be repeated here.

[0080] In order to better understand the coherent burst receiving local oscillator laser output power adjustment device and method of the present application, the device and method of the present application will be described in detail below with reference to the accompanying drawings, taking the application scenario of the dual-polarization receiving mode as an example.

[0081] Reference Figure 8 As shown, Figure 8 Schematic diagram of the output power adjustment device of the local oscillator laser for coherent burst reception based on dual polarization reception. Figure 8 As shown, a coherent burst receiving local oscillator laser output power adjustment device includes: a local oscillator laser and its control unit, a burst coherent receiving component, and a burst processing control unit. Among them, the burst coherent receiving component is mainly composed of a polarization beam splitter, a 90° mixer, a balanced diode, and a transimpedance amplifier; the burst processing control unit is pre-set with power high and low threshold values ​​and a table of power and LO bias current relationships, with the high power threshold value being denoted as Ph and the low power threshold value being denoted as Pl; the local oscillator laser and its control unit are pre-set with the local oscillator laser's initial frequency f Lo The control unit can adjust the output optical power accordingly according to the control signal of the burst processing control unit.

[0082] Reference Figure 9 As shown, Figure 9 FIG. 1 is a flow chart of a method for adjusting the output power of a local oscillator laser for coherent burst reception based on dual-polarization reception. Figure 9 As shown, a method for adjusting the output power of a coherent burst receiving local oscillator laser comprises the following steps:

[0083] S901, the burst coherent receiving component receives the burst signal light from different ONUs and the light output by the local oscillator laser, completes the optical-to-electrical conversion and outputs the amplified electrical signal to the burst processing control unit;

[0084] S902, the burst processing control unit detects the initial frequency f of the local oscillator laser Lo The signal frequency f of the ONU burst signal light s Frequency deviation Δf, Δf=f s -f Lo If the positive bias Δf>+Δf0, the burst processing control unit outputs a positive bias frequency adjustment control signal to the local oscillator laser control unit, so that it adjusts the local oscillator laser frequency toward high frequency until the frequency deviation Δf is within the normal frequency range Δf0 agreed upon by the system; if the negative bias Δf<-Δf0, the burst processing control unit outputs a negative bias frequency adjustment control signal to the local oscillator laser control unit, so that it adjusts the local oscillator laser frequency toward low frequency until the frequency deviation Δf is within the normal frequency range Δf0 agreed upon by the system;

[0085] S903: The burst processing control unit detects the output optical power of the signal light after deflection correction and the local oscillator light after mixing, which is recorded as Po.

[0086] S904, determine whether the current Po is within the power high and low thresholds [Pl, Ph], if so, go to step S905; otherwise, go to step S906;

[0087] S905, controlling the local oscillator laser to output the adjusted power, and ending this adjustment;

[0088] S906, determine whether the current Po is higher than the high power threshold Ph or lower than the low power threshold Pl, if higher than Ph, go to step S907; if lower than Pl, go to step S908;

[0089] S907: According to the power and LO bias current mapping table, output a power adjustment control signal to the local oscillator laser control unit to reduce the output optical power of the local oscillator laser. The reduction step size is determined according to the actual system, and Po is updated and the process returns to step S904.

[0090] S908. According to the power and LO bias current mapping table, output a power adjustment control signal to the local oscillator laser control unit to increase the output optical power of the local oscillator laser. The increase step size is determined according to the actual system, and Po is updated and returned to step S904.

[0091] From the above content, it can be seen that the device and method of the present application realize the ability to adjust the output optical power of the local oscillator laser during coherent burst reception, thereby increasing the dynamic range of coherent burst reception, thereby solving the bit error problem caused by different received signal light sizes when OLT burst reception and the output optical power of the OLT local oscillator laser is fixed.

[0092] Note: The above-mentioned specific embodiments are merely examples and not limitations, and those skilled in the art can, based on the concept of the present invention, merge and combine some steps and devices from the various embodiments described separately above to achieve the effects of the present invention. Such merged and combined embodiments are also included in the present invention, and such merges and combinations are not described one by one here.

[0093] The advantages, strengths, and effects mentioned in the embodiments of the present invention are merely illustrative and non-limiting, and should not be construed as necessarily possessed by each embodiment of the present invention. Furthermore, the specific details disclosed in the embodiments of the present invention are provided for illustrative purposes only and to facilitate understanding, rather than as limitations. These details do not necessarily limit the embodiments of the present invention to the use of these specific details.

[0094] The block diagrams of the devices, apparatuses, equipment, and systems involved in the embodiments of the present invention are intended to be illustrative examples only and are not intended to require or imply that they must be connected, arranged, or configured in the manner shown in the block diagrams. As will be appreciated by those skilled in the art, these devices, apparatuses, equipment, and systems may be connected, arranged, or configured in any manner. Words such as "include," "comprise," "have," and the like are open-ended words, meaning "including but not limited to," and may be used interchangeably therewith. The words "or" and "and" used in the embodiments of the present invention refer to the words "and / or" and may be used interchangeably therewith, unless the context clearly indicates otherwise. The word "such as" used in the embodiments of the present invention refers to the phrase "such as but not limited to," and may be used interchangeably therewith.

[0095] The step flow charts and the above method descriptions in the embodiments of the present invention are merely illustrative examples and are not intended to require or imply that the steps of the various embodiments must be performed in the order given. As will be appreciated by those skilled in the art, the order of the steps in the above embodiments can be performed in any order. Words such as "thereafter," "then," "next," and the like are not intended to limit the order of the steps; these words are only used to guide the reader through the description of these methods. In addition, any reference to a singular element, such as using the articles "a," "an," or "the," is not to be construed as limiting the element to the singular.

[0096] In addition, the steps and devices in each embodiment of the present invention are not limited to being implemented in a certain embodiment. In fact, based on the concept of the present invention, relevant partial steps and partial devices in each embodiment of this document can be combined to conceive new embodiments, and these new embodiments are also included in the scope of the present invention.

[0097] Each operation in the embodiments of the present invention may be performed by any appropriate means capable of performing the corresponding functions, which may include various hardware and / or software components and / or modules, including but not limited to hardware circuits or processors.

[0098] The methods of the embodiments of the present invention include one or more actions for implementing the above-described methods. The methods and / or actions may be interchangeable with each other without departing from the scope of the claims. In other words, unless a specific order of actions is specified, the order and / or use of the specific actions may be modified without departing from the scope of the claims.

[0099] Various changes, substitutions, and modifications of the techniques described herein may be made by those skilled in the art without departing from the teachings defined by the appended claims. Furthermore, the scope of the claims of this disclosure is not limited to the specific aspects of the processes, machines, manufactures, compositions of things, means, methods, and actions described above. Currently existing or later developed processes, machines, manufactures, compositions of things, means, methods, or actions that perform substantially the same functions or achieve substantially the same results as the corresponding aspects described herein may be utilized. Accordingly, the appended claims include within their scope such processes, machines, manufactures, compositions of things, means, methods, or actions.

[0100] The above description of the disclosed aspects is provided to enable any person skilled in the art to make or use the present invention. Various modifications to these aspects will be readily apparent to those skilled in the art, and the general principles defined herein may be applied to other aspects without departing from the scope of the present invention. Therefore, the present invention is not intended to be limited to the aspects shown herein, but rather to be accorded the widest scope consistent with the principles and novel features disclosed herein.

[0101] The foregoing description has been presented for purposes of illustration and description. Furthermore, this description is not intended to limit the embodiments of the present invention to the forms disclosed herein. While various exemplary aspects and embodiments have been discussed above, those skilled in the art will recognize certain variations, modifications, alterations, additions, and sub-combinations thereof. Furthermore, matters not described in detail herein constitute prior art known to those skilled in the art.

Claims

1. A coherent burst receiving local oscillator laser output power adjustment device, characterized in that: The device includes: A burst coherent receiving component is used to: complete the photoelectric conversion and amplify the electrical signal, and output the signal data to the burst processing control unit; A burst processing control unit, which is internally provided with power high and low thresholds and a table of power and LO bias current relationships, is used to correct the frequency offset of the local oscillator laser; compare the optical power of the corrected signal light and the local oscillator light after mixing with the power high and low thresholds, and output a corresponding power control signal to the local oscillator laser and its control unit based on the comparison result and the power and LO bias current relationship table; A local oscillator laser and a control unit thereof are used to adjust the output optical power according to a received power control signal.

2. The coherent burst receiving local oscillator laser output power adjustment device according to claim 1, characterized in that: The burst processing control unit corrects the frequency offset of the local oscillator laser, including: The burst processing control unit detects the initial frequency f of the local oscillator laser Lo The signal frequency f of the ONU burst signal light s Frequency deviation Δf, Δf=f s -f Lo ; If the positive bias Δf>+Δf0, Δf0 is the normal frequency range agreed by the system, then the positive bias frequency adjustment control signal is output to the local oscillator laser control unit, so that it adjusts the local oscillator laser frequency toward the high frequency direction until Δf is within Δf0; If the negative bias Δf is less than -Δf0, a negative bias frequency adjustment control signal is output to the local oscillator laser control unit to adjust the local oscillator laser frequency toward a low frequency until Δf is within Δf0.

3. The coherent burst receiving local oscillator laser output power adjustment device according to claim 1, characterized in that: The burst processing control unit compares the optical power of the signal light after deflection correction and the local oscillator light after mixing with the high and low power thresholds, and outputs a corresponding power control signal to the local oscillator laser and its control unit based on the comparison result and in combination with the power and LO bias current relationship table, including: The burst processing control unit detects the optical power of the corrected signal light and the mixed local oscillator light, and compares it with the high and low power thresholds; If the power is greater than the high power threshold, a power adjustment control signal for reducing the power is output to the local oscillator laser control unit according to the power and LO bias current mapping table; If the power is less than the low power threshold, a power adjustment control signal for increasing the power is output to the local oscillator laser control unit according to the power and LO bias current mapping table.

4. The coherent burst receiving local oscillator laser output power adjustment device according to claim 3, characterized in that: The burst processing control unit is further configured to determine whether the adjusted optical power is within the power high and low thresholds; if so, control the local oscillator laser to output the adjusted power and terminate the current adjustment; otherwise, repeat the adjustment until the adjusted optical power is within the power high and low thresholds.

5. The coherent burst receiving local oscillator laser output power adjustment device according to claim 1, characterized in that: The burst coherent receiving component includes: The first device is used to: complete polarization splitting of the signal light and the local oscillator laser light signal; The second device is used to: complete the mixing output of the optical signal; The third device is used to: complete photoelectric conversion and output current; The fourth device is used to convert the current into a voltage signal and amplify the voltage signal and output it to the burst processing control unit.

6. The coherent burst receiving local oscillator laser output power adjustment device according to claim 5, characterized in that: The first device includes a polarization beam splitter; the second device includes a 90° mixer or a 2×2 coupler; the third device includes a balanced diode or a single diode; and the fourth device includes a transimpedance amplifier.

7. The coherent burst receiving local oscillator laser output power adjustment device according to claim 6, characterized in that: If the receiving end adopts a dual-polarization receiving mode, the first component of the burst coherent receiving component is a polarization beam splitter, the second component is a 90° mixer, the third component is a balanced diode, and the fourth component is a transimpedance amplifier.

8. The coherent burst receiving local oscillator laser output power adjustment device according to claim 6, characterized in that: If the receiving end adopts a single polarization receiving mode, the burst coherent receiving component omits the first device, and the second device is a 2×2 coupler, the third device is a balanced diode, and the fourth device is a transimpedance amplifier.

9. The coherent burst receiving local oscillator laser output power adjustment device according to claim 6, characterized in that: If the receiving end adopts a single-polarization minimalist receiving mode, the burst coherent receiving component omits the first device, and the second device is a 2×2 coupler, the third device is a single diode, and the fourth device is a transimpedance amplifier.

10. An OLT device, characterized in that: The OLT device is provided with the coherent burst receiving local oscillator laser output power adjustment device according to any one of claims 1 to 9.

11. A method for adjusting the output power of a coherent burst receiving local oscillator laser based on the device according to any one of claims 1 to 9, characterized in that: The method comprises the following steps: The burst coherent receiving component receives the burst signal light from different ONUs and the light output by the local oscillator laser, completes the photoelectric conversion and outputs the amplified electrical signal to the burst processing control unit; The burst processing control unit corrects the frequency offset of the local oscillator laser and compares the optical power of the corrected signal light and the mixed local oscillator light with the built-in power high and low thresholds. Based on the comparison result and the built-in power and LO bias current relationship table, it outputs the corresponding power control signal to the local oscillator laser and its control unit. The local oscillator laser and its control unit adjust the output optical power according to the received power control signal.

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