A light source detection and correction system and method

Abstract

The present invention provides a light source detection and correction system and method, including a coupler, a filter, a detector and a control module; the coupler transmits part of the light emitted by the light source to the filter, the filter filters part of the light, and transmits part of the light to the detector, the detector detects the light intensity of the part of the light, and transmits the detected light intensity value to the control module, the control module determines whether the light source drifts according to the detected light intensity value, and corrects the light source after determining that the light source drifts. The light source detection and correction system and method provided by the present invention can timely detect the drift of the light source, timely correct the drift, and can greatly reduce the cycle and tediousness of the light source drift correction.

Description

Technical Field

[0001] The present invention relates to the technical field of optical communication and quantum communication, and more specifically, to a light source detection and correction system and method. Background Art

[0002] Laser injection locking technology is mostly used in the fields of optical communication and quantum communication technology. It is mainly used to improve the modulation bandwidth of semiconductor lasers and the nonlinear effects such as bistability and four-wave mixing exhibited by lasers during strong injection locking.

[0003] In the field of quantum communication technology, due to the wavelength inconsistency problem of multiple lasers in the QKD (Quantum Key Distribution) system and the poor quality of light pulses of a single laser, the QKD system will have security vulnerabilities and poor performance. The injection locking technology can overcome this problem well.

[0004] However, in practical applications, lasers are often affected by factors such as temperature and drift, which affects the effect and quality of injection locking. Most of the existing technologies use instruments such as spectrometers to re-debug and calibrate the lasers. However, this debugging and correction method cannot detect the drift of the laser in time, nor can it correct the drift of the laser in time, which is not conducive to the application of the laser. Summary of the invention

[0005] In view of this, the present invention provides a light source detection and correction system and method, so as to timely discover the drift of a light source such as a laser, and correct the drift in a timely manner.

[0006] To achieve the above object, the present invention provides the following technical solutions:

[0007] A light source detection and correction system includes a coupler, a filter, a detector and a control module;

[0008] The coupler is used to transmit part of the light emitted by the light source to the filter to achieve online detection of the light source;

[0009] The filter is used to filter the part of light and transmit the part of light to the detector; the bandwidth of the filter matches the spectral line width of the light source;

[0010] The detector is used to detect the light intensity of the part of light and transmit the detected light intensity value to the control module;

[0011] The control module is used to determine whether the light source drifts according to the detected light intensity value, and to calibrate the light source after determining that the light source drifts.

[0012] Optionally, the control module determines whether the light source drifts according to the detected light intensity value, including determining whether the light intensity value is within a preset threshold value range, if so, the light source does not drift, if not, the light source drifts;

[0013] The control module calibrates the light source by performing fine adjustment on the temperature of the light source, or performs fine adjustment on the delay and the temperature of the light source.

[0014] Optionally, the light source is an injection-locked light source, and the injection-locked light source includes a master laser, a slave laser and a circulator;

[0015] The first end of the circulator is connected to the master laser, the second end of the circulator is connected to the slave laser, and the third end of the circulator is connected to the coupler;

[0016] The circulator is used to transmit the laser light emitted by the master laser to the slave laser so as to injection lock the laser light emitted by the slave laser;

[0017] The circulator is further used to transmit the laser light emitted from the laser to the coupler, so that the coupler transmits part of the laser light emitted from the laser to the filter.

[0018] Optionally, the detector is a single photon detector; and the control module is an FPGA chip, an MCU or a micro CPU.

[0019] Optionally, a power detection circuit is also included;

[0020] The light intensity value detected by the detector is transmitted to the control module after being detected by the power detection circuit.

[0021] A light source detection and correction method, applied to the light source detection and correction system as described in any one of the above items, comprising:

[0022] The coupler transmits part of the light emitted by the light source to the filter to realize online detection of the light source;

[0023] The filter filters the portion of light and transmits the portion of light to the detector;

[0024] The detector detects the light intensity of the part of light and transmits the detected light intensity value to the control module;

[0025] The control module determines whether the light source drifts according to the detected light intensity value, and if so, calibrates the light source.

[0026] Optionally, judging whether the light source drifts according to the detected light intensity value includes:

[0027] Determining whether the light intensity value is within a preset threshold range;

[0028] If yes, it is determined that the light source does not drift;

[0029] If not, it is determined that the light source is drifting.

[0030] Optionally, calibrating the light source includes:

[0031] Fine-tuning the temperature of the light source;

[0032] Alternatively, the light source is finely adjusted in time delay and temperature.

[0033] Optionally, fine-tuning the temperature of the light source includes:

[0034] adjusting the temperature of the light source, and judging whether the light source drifts according to the light intensity value detected by the detector;

[0035] If yes, continue to adjust the temperature of the light source until it is determined that the light source has not drifted according to the light intensity value detected by the detector;

[0036] If not, end the calibration process.

[0037] Optionally, delay fine-tuning and temperature fine-tuning of the light source include:

[0038] Adjusting the delay value of the light source, and judging whether the light source drifts according to the light intensity value detected by the detector;

[0039] If yes, adjust the temperature value of the light source, and if the light source is still determined to have drifted according to the light intensity value detected by the detector, adjust the delay value of the light source, and repeat this process until the light source is determined to have not drifted according to the light intensity value detected by the detector;

[0040] If not, end the calibration process.

[0041] Compared with the prior art, the technical solution provided by the present invention has

[0042] The following advantages:

[0043] In the light source detection and correction system and method provided by the present invention, the coupler transmits part of the light emitted by the light source to the filter, the filter filters part of the light, and transmits part of the light to the detector; after the detector detects the light intensity of part of the light, the detected light intensity value is transmitted to the control module, and the control module determines whether the light source drifts according to the detected light intensity value, and corrects the light source after determining that the light source drifts. By using the light source detection and correction system and method provided by the present invention, the drift of the light source can be discovered in time, the drift can be corrected in time, and the cycle and tediousness of light source drift correction can be greatly reduced. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the provided drawings without paying creative work.

[0045] Figure 1 A structural schematic diagram of a light source detection and correction system provided by the present invention;

[0046] Figure 2 A schematic diagram of the structure of another light source detection and correction system provided by the present invention;

[0047] Figure 3 The present invention provides a flow chart of a light source detection and correction method. DETAILED DESCRIPTION

[0048] As described in the background technology, in practical applications, lasers are often affected by a series of factors and drift, affecting the effect and quality of injection locking. Most of the existing technologies use instruments such as spectrometers to re-debug and calibrate the lasers. However, this debugging and correction method cannot detect the drift of the laser in time, nor can it correct the drift of the laser in time, which is not conducive to the application of the laser.

[0049] Based on this, the present invention provides a light source detection and correction system to overcome the above problems existing in the prior art, including a coupler, a filter, a detector and a control module;

[0050] The coupler is used to transmit part of the light emitted by the light source to the filter to achieve online detection of the light source;

[0051] The filter is used to filter the part of light and transmit the part of light to the detector; the bandwidth of the filter matches the spectral line width of the light source;

[0052] The detector is used to detect the light intensity of the part of light and transmit the detected light intensity value to the control module;

[0053] The control module is used to determine whether the light source drifts according to the detected light intensity value, and to calibrate the light source after determining that the light source drifts.

[0054] The present invention also provides a light source detection and correction method, which is applied to the light source detection and correction system as described above, comprising:

[0055] The coupler transmits part of the light emitted by the light source to the filter to realize online detection of the light source;

[0056] The filter filters the portion of light and transmits the portion of light to the detector;

[0057] The detector detects the light intensity of the part of light and transmits the detected light intensity value to the control module;

[0058] The control module determines whether the light source drifts according to the detected light intensity value, and calibrates the light source when it is determined that the light source drifts.

[0059] The light source detection and correction system and method provided by the present invention, the coupler transmits part of the light emitted by the light source to the filter, the filter filters part of the light, and transmits part of the light to the detector, the detector detects the light intensity of the part of the light, and transmits the detected light intensity value to the control module, the control module determines whether the light source drifts according to the detected light intensity value, and corrects the light source after determining that the light source drifts. The light source detection and correction system and method provided by the present invention can timely detect the drift of the light source, timely correct the drift, and can greatly reduce the cycle and tediousness of the light source drift correction.

[0060] The above is the core idea of ​​the present invention. In order to make the above-mentioned purposes, features and advantages of the present invention more obvious and easy to understand, the technical solutions in the embodiments of the present invention will be clearly and completely described below in combination with the drawings in the embodiments of the present invention. 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 the present invention.

[0061] The embodiment of the present invention provides a light source detection and correction system, which is a closed-loop control system that can perform online detection and feedback adjustment on a light source. Figure 1As shown, the light source detection and correction system provided by the embodiment of the present invention includes a coupler 20 , a filter 21 , a detector 22 and a control module 23 .

[0062] It should be noted that the light source detection and correction system provided in the embodiment of the present invention is applied to injection-locked light sources and non-injection-locked light sources. The non-injection-locked light sources can be lasers or light-emitting diodes, etc. Of course, the present invention is not limited to this.

[0063] Among them, the coupler 20 is used to transmit part of the light emitted by the light source 1 to the filter 21 to realize online detection of the light source 1; the filter 21 is used to filter the part of the light and transmit the part of the light to the detector 22; the detector 22 is used to detect the light intensity of the part of the light and transmit the detected light intensity value to the control module 23; the control module 23 is used to determine whether the light source 1 drifts according to the detected light intensity value, and after determining that the light source 1 drifts, calibrate the light source 1.

[0064] In this embodiment, the bandwidth of the filter 21 matches the spectral line width of the light source 1. This is because when the light source 1 drifts, the spectral line width of the light source 1 will exceed the passband range of the filter 21, which will cause the light intensity value detected by the detector 22 to change. Therefore, it can be determined whether the light source 1 has drifted according to the change in the light intensity value detected by the detector 22.

[0065] Specifically, the control module 23 determines whether the light source 1 drifts according to the detected light intensity value, including: determining whether the light intensity value is within a preset threshold range, if so, the light source 1 has not drifted, if not, the light source 1 has drifted.

[0066] Optionally, the detector 22 in the embodiment of the present invention is a single-photon detector, which records the light intensity value in a counting manner. In the normal working stage of the light source 1, the single-photon detector transmits the count value corresponding to the light intensity value of part of the light of the light source 1 to the control module 23, and the control module 23 determines whether the count value is within a preset threshold range. If the count value is within the preset threshold range, it means that the state of the light source 1 is normal and no drift occurs. The single-photon detector continues to detect the light intensity value of the light source 1, and the control module 23 continues to make judgments. If the count value is not within the preset threshold range, it means that the light source 1 has drifted, and the control module 23 will control the light source 1 to stop working and calibrate the light source 1.

[0067] Specifically, the control module 23 calibrates the light source 1 by fine-tuning the temperature of the light source 1, or fine-tuning the delay and temperature of the light source 1. Of course, the present invention is not limited thereto, and in other embodiments, the control module 23 may also calibrate the light source 1 in other ways.

[0068] Optionally, the control module 23 fine-tunes the temperature of the light source 1, including:

[0069] The control module 23 adjusts the temperature of the light source 1, such as increasing or decreasing the temperature value of the light source 1, and determines whether the light source 1 still drifts according to the light intensity value detected by the detector 22; if there is still drift, continue to adjust the temperature of the light source 1 until it is determined that the light source 1 no longer drifts according to the light intensity value detected by the detector 22, and then the calibration process is terminated, and the control module 23 controls the light source 1 to enter a normal working state; if there is no drift, the calibration process is terminated, and the control module 23 controls the light source 1 to enter a normal working state.

[0070] Furthermore, before continuing to adjust the temperature of the light source 1, the light intensity value currently detected by the detector 22 can be compared with the light intensity value detected last time. If the currently detected light intensity value is larger, the temperature value is further increased or decreased based on the current temperature. If the currently detected light intensity value is smaller, the temperature value is further decreased or increased based on the current temperature, i.e., the temperature value is reversely adjusted. Optionally, the temperature value increased or decreased each time is 0.1°C.

[0071] Optionally, the control module 23 performs delay fine adjustment and temperature fine adjustment on the light source 1, including:

[0072] The control module 23 adjusts the delay value of the light source 1, and determines whether the light source 1 is still drifting according to the light intensity value detected by the detector 22. If there is no drift, the calibration process ends. If there is still drift, the temperature of the light source 1 is adjusted. If the light source 1 is still determined to be drifting according to the light intensity value detected by the detector 22, the delay value of the light source 1 is adjusted, and the cycle is repeated until it is determined that the light source 1 is not drifting according to the light intensity value detected by the detector 22, and the calibration process ends. The control module 23 controls the light source 1 to enter a normal working state.

[0073] Specifically, the control module 23 adjusts the delay value of the light source 1, such as increasing or decreasing the delay value of the light source 1, so that the delay value takes values ​​in sequence within a preset delay value range. If one of the delay values ​​makes it determined that the light source 1 has not drifted according to the light intensity value detected by the detector 22, the calibration process is terminated. If, after taking values ​​in sequence within the preset delay value range, it is still determined that the light source 1 has drifted according to the light intensity value detected by the detector 22, the delay value corresponding to the light intensity value threshold closest to the light intensity value without drift is selected as the delay value of the light source 1, and the temperature of the light source 1 is adjusted, such as increasing or decreasing the temperature value of the light source 1, so that the temperature is within the preset range. The temperature values ​​are taken in sequence within the preset range. If one of the temperature values ​​makes it determined that the light source 1 has not drifted according to the light intensity value detected by the detector 22, the calibration process is terminated. If, after taking values ​​in sequence within the preset range of temperature values, the light source 1 is still determined to have drifted according to the light intensity value detected by the detector 22, the temperature value corresponding to the light intensity value threshold closest to the drift-free state is selected as the temperature of the light source 1, and the delay value of the light source 1 is adjusted again. This cycle is repeated until it is determined that the light source 1 has not drifted according to the light intensity value detected by the detector 22. The calibration process is terminated and the control module 23 controls the light source 1 to enter a normal working state.

[0074] Furthermore, in the process of taking values ​​in sequence within the preset delay value range, before taking values ​​again, the light intensity value currently detected by the detector 22 can be compared with the light intensity value detected last time. If the currently detected light intensity value is larger, the delay value is further increased or decreased based on the current delay value. If the currently detected light intensity value is smaller, the delay value is further decreased or increased based on the current delay value, i.e., the delay value is reversely debugged. Optionally, the delay value increased or decreased each time is 11ps.

[0075] Similarly, in the process of taking values ​​in sequence within the preset temperature range, before taking values ​​again, the light intensity value currently detected by the detector 22 can be compared with the light intensity value detected last time. If the currently detected light intensity value is larger, the temperature value is further increased or decreased based on the current temperature. If the currently detected light intensity value is smaller, the temperature value is further decreased or increased based on the current temperature, i.e., the temperature value is reversely debugged. Optionally, the temperature value increased or decreased each time is 0.1°C.

[0076] Optionally, the light source detection and correction system provided by the embodiment of the present invention further includes a power detection circuit;

[0077] The light intensity value detected by the detector 22 is detected by the power detection circuit and then transmitted to the control module 23 .

[0078] In one embodiment of the present invention, Figure 2 As shown, the light source 1 is an injection-locked light source, which includes a master laser 10 , a slave laser 11 and a circulator 12 .

[0079] The first end 1 of the circulator 12 is connected to the master laser 10, the second end 2 of the circulator 12 is connected to the slave laser 11, and the third end 3 of the circulator 12 is connected to the coupler 20; the circulator 12 is used to transmit the laser light emitted by the master laser 10 to the slave laser 11, so as to injection lock the emitted laser light of the slave laser 11; the circulator 12 is also used to transmit the laser light emitted by the slave laser 11 to the coupler 20, so that the coupler 20 transmits part of the laser light emitted by the laser 11 to the filter 21.

[0080] In this embodiment, when the light source 1 is an injection-locked light source, the filter 21 is a narrowband filter, including fiber grating type filters such as temperature compensated gratings and phase-shifted gratings, or other narrowband filtering functional devices, which are not limited to fiber optic devices, but can also be filtering devices such as spatial optics.

[0081] Furthermore, the coupler 20 is preferably a single-mode coupler, but the present invention is not limited thereto. The control module 23 may be a FPGA (Field-Programmable Gate Array) chip or an MCU (Microcontroller Unit).

[0082] The light source detection and correction system provided by the embodiment of the present invention is a process of actively detecting the parameters of the injection locked light source in the QKD system, judging the online state performance of the light source through the dynamic detection results of the parameters, and performing self-stabilization processing on the light source. The specific process of detecting and correcting the injection locked light source is as follows:

[0083] The control module 23 controls the master laser 10 and the slave laser 11 to enter the working state, the circulator 12 transmits the laser light emitted by the master laser 10 to the slave laser 11, and performs injection locking on the laser light emitted by the slave laser 11. After that, the circulator 12 transmits the laser light emitted by the slave laser 11 to the coupler 20, and the coupler 20 transmits part of the laser light emitted by the laser 11 to the filter 21, and transmits the other part of the laser light to the main transmission link of the QKD optical path, so that the injection locked light source can be detected online without affecting the normal working state of the QKD system.

[0084] Part of the light emitted from the laser 11 passes through the filter 21 and is detected by the detector 22. The data detected by the detector 22, i.e., the light intensity value, is detected by the power detection circuit and uploaded to the control module 23. The control module 23 determines whether the injection-locked light source has drifted or lost lock. If drift or loss of lock occurs, the control module 23 will report the abnormality to the QKD system, terminate the relevant process of the QKD system, and enter the abnormal stage. In the abnormal stage, the control module 23 will adjust the delay value of the master laser 10 or the slave laser 11, and adjust the temperature value of the master laser 10 to calibrate the injection-locked light source. If there is no drift or loss of lock, the coupler 20, filter 21, detector 22 and control module 23 will continue to detect the injection-locked light source.

[0085] Among them, the control module 23 can first adjust the delay value of the master laser 10 or the slave laser 11. If the light intensity value is still not within the preset threshold range after taking values ​​in sequence within the preset delay value range, the control module 23 will select the delay value closest to the threshold as the delay value of the master laser 10 or the slave laser 11. Then, the control module 23 will adjust the temperature value of the master laser 10. Similarly, if the light intensity value is still not within the preset threshold range after taking values ​​in sequence within the preset temperature value range, the control module 23 will select the temperature value closest to the threshold as the temperature value of the master laser 10. After that, the control module 23 will adjust the delay value of the master laser 10 or the slave laser 11 again, and so on. The cycle continues until the detected light intensity value is still within the preset threshold range.

[0086] In the embodiment of the present invention, the use of optical injection locking technology can greatly improve the optical pulse performance of the laser 11, and realize the narrow line width output from the laser 11. After part of the light output from the laser 11 enters the monitoring link through the coupler 20, the narrowband filter 21 and the detector 22 are used to detect the light intensity value.

[0087] The light source detection and correction system provided by the present invention can timely discover the drift of the light source, correct the drift in time, and can greatly reduce the cycle and complexity of the light source drift correction.

[0088] The embodiment of the present invention further provides a light source detection and correction method, which is applied to the light source detection and correction system provided in the above embodiment. Figure 3 As shown, including:

[0089] S301: The coupler transmits part of the light emitted by the light source to the filter to realize online detection of the light source;

[0090] S302: The filter filters the portion of light and transmits the portion of light to a detector;

[0091] S303: The detector detects the light intensity of the partial light, and transmits the detected light intensity value to the control module;

[0092] S304: the control module determines whether the light source drifts according to the detected light intensity value, and if so, proceeds to S305, and if not, proceeds to S301;

[0093] S305: Calibrate the light source.

[0094] Wherein, judging whether the light source drifts according to the detected light intensity value includes:

[0095] Determining whether the light intensity value is within a preset threshold range;

[0096] If yes, it is determined that the light source does not drift;

[0097] If not, it is determined that the light source is drifting.

[0098] Optionally, the detector is a single-photon detector, which records the light intensity value in a counting manner. During the normal working stage of the light source, the single-photon detector transmits the count value corresponding to the light intensity value of part of the light source to the control module, and the control module determines whether the count value is within a preset threshold range. If the count value is within the preset threshold range, it means that the light source is normal and no drift occurs. The single-photon detector continues to detect the light intensity value of the light source, and the control module continues to make judgments. If the count value is not within the preset threshold range, it means that the light source has drifted. The control module will control the light source to stop working and calibrate the light source.

[0099] Optionally, calibrating the light source includes: fine-tuning the temperature of the light source; or fine-tuning the delay and temperature of the light source.

[0100] Further, fine-tuning the temperature of the light source comprises:

[0101] adjusting the temperature of the light source, and judging whether the light source drifts according to the light intensity value detected by the detector;

[0102] If yes, continue to adjust the temperature of the light source until it is determined that the light source has not drifted according to the light intensity value detected by the detector;

[0103] If not, end the calibration process.

[0104] Specifically, the control module adjusts the temperature of the light source, such as increasing or decreasing the temperature value of the light source, and determines whether the light source still drifts according to the light intensity value detected by the detector; if there is still drift, continue to adjust the temperature of the light source until it is determined that the light source no longer drifts according to the light intensity value detected by the detector, and then terminate the calibration process, and the control module controls the light source to enter a normal working state; if there is no drift, terminate the calibration process, and the control module controls the light source to enter a normal working state.

[0105] Furthermore, before continuing to adjust the temperature of the light source, the light intensity value currently detected by the detector can be compared with the light intensity value detected last time. If the currently detected light intensity value is larger, the temperature value is further increased or decreased based on the current temperature. If the currently detected light intensity value is smaller, the temperature value is further decreased or increased based on the current temperature, i.e., the temperature value is reversely adjusted. Optionally, the temperature value increased or decreased each time is 0.1°C.

[0106] Furthermore, the light source is subjected to time delay fine adjustment and temperature fine adjustment, including:

[0107] Adjusting the delay value of the light source, and judging whether the light source drifts according to the light intensity value detected by the detector;

[0108] If yes, adjust the temperature of the light source, and if the light source is still determined to have drifted according to the light intensity value detected by the detector, adjust the delay value of the light source, and repeat this process until the light source is determined to have not drifted according to the light intensity value detected by the detector;

[0109] If not, end the calibration process.

[0110] Specifically, the delay value of the light source is first adjusted, such as increasing or decreasing the delay value of the light source, so that the delay value takes values ​​in sequence within a preset delay value range. If one of the delay values ​​makes it determined that the light source has not drifted according to the light intensity value detected by the detector after taking values ​​in sequence within the preset delay value range, the correction process is terminated. If the light source is still determined to have drifted according to the light intensity value detected by the detector after taking values ​​in sequence within the preset delay value range, the delay value corresponding to the light intensity value threshold closest to the drift-free light intensity value is selected as the delay value of the light source, and the temperature of the light source is adjusted, such as increasing or decreasing the temperature value of the light source, so that the temperature takes values ​​in sequence within a preset temperature value range. If one of the temperature values ​​makes it determined that the light source has not drifted according to the light intensity value detected by the detector after taking values ​​in sequence within the preset temperature value range, the correction process is terminated. If the light source is still determined to have drifted according to the light intensity value detected by the detector after taking values ​​in sequence within the preset temperature value range, the temperature value corresponding to the light intensity value threshold closest to the drift-free light intensity value is selected as the temperature of the light source, and the delay value of the light source is adjusted again, and this cycle is repeated until it is determined that the light source has not drifted according to the light intensity value detected by the detector, the correction process is terminated, and the light source is controlled to enter a normal working state.

[0111] That is to say, when fine-tuning the delay and temperature of the light source, you can first fine-tune the delay of the light source. If the delay adjustment is unsuccessful, that is, the light intensity value after adjustment is still not within the preset threshold range, then the delay value of the light source is set to the delay value closest to the threshold, and perform temperature fine-tuning. If the temperature adjustment is unsuccessful, then the temperature value of the light source is set to the temperature value closest to the threshold, and perform delay fine-tuning. This cycle is repeated until the adjusted light intensity value is within the preset threshold range.

[0112] Furthermore, in the process of taking values ​​in sequence within the preset delay value range, before taking values ​​again, the light intensity value currently detected by the detector can be compared with the light intensity value detected last time. If the currently detected light intensity value is larger, the delay value is further increased or decreased based on the current delay value. If the currently detected light intensity value is smaller, the delay value is further decreased or increased based on the current delay value, i.e., the delay value is reversely debugged. Optionally, the delay value increased or decreased each time is 11ps.

[0113] Similarly, in the process of taking values ​​in sequence within the preset temperature range, before taking values ​​again, the light intensity value currently detected by the detector 22 can be compared with the light intensity value detected last time. If the currently detected light intensity value is larger, the temperature value is further increased or decreased based on the current temperature. If the currently detected light intensity value is smaller, the temperature value is further decreased or increased based on the current temperature, i.e., the temperature value is reversely debugged. Optionally, the temperature value increased or decreased each time is 0.1°C.

[0114] The light source detection and correction method provided by the present invention can timely discover the drift of the light source, correct the drift in time, and can greatly reduce the cycle and complexity of the light source drift correction.

[0115] In this specification, each embodiment is described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same or similar parts between the embodiments can be referred to each other. For the device disclosed in the embodiment, since it corresponds to the method disclosed in the embodiment, the description is relatively simple, and the relevant parts can be referred to the method part.

[0116] The above description of the disclosed embodiments enables one skilled in the art to implement or use the present invention. Various modifications to these embodiments will be apparent to one skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to the embodiments shown herein, but rather to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A light source detection and correction system, characterized in that: Includes coupler, filter, detector and control module; The coupler is used to transmit part of the light emitted by the light source to the filter to achieve online detection of the light source; The filter is used to filter the part of light and transmit the part of light to the detector; The bandwidth of the filter matches the spectral linewidth of the light source; The detector is used to detect the light intensity of the part of light and transmit the detected light intensity value to the control module; The control module is used to determine whether the light source drifts according to the detected light intensity value, and to calibrate the light source after determining that the light source drifts.

2. The system according to claim 1, characterized in that The control module determines whether the light source drifts according to the detected light intensity value, including determining whether the light intensity value is within a preset threshold value range, if so, the light source does not drift, if not, the light source drifts; The control module calibrates the light source by performing fine adjustment on the temperature of the light source, or performs fine adjustment on the delay and the temperature of the light source.

3. The system according to claim 1 or 2, characterized in that: The light source is an injection-locked light source, and the injection-locked light source includes a master laser, a slave laser and a circulator; The first end of the circulator is connected to the master laser, the second end of the circulator is connected to the slave laser, and the third end of the circulator is connected to the coupler; The circulator is used to transmit the laser light emitted by the master laser to the slave laser so as to injection lock the laser light emitted by the slave laser; The circulator is further used to transmit the laser light emitted from the laser to the coupler, so that the coupler transmits part of the laser light emitted from the laser to the filter.

4. The system according to claim 1, characterized in that The detector is a single photon detector; the control module is an FPGA chip, an MCU or a micro CPU.

5. The system according to claim 1, characterized in that Also included is a power detection circuit; The light intensity value detected by the detector is transmitted to the control module after being detected by the power detection circuit.

6. A light source detection and calibration method, characterized in that: The light source detection and correction system according to any one of claims 1 to 5 comprises: The coupler transmits part of the light emitted by the light source to the filter to realize online detection of the light source; The filter filters the portion of light and transmits the portion of light to the detector; The detector detects the light intensity of the part of light and transmits the detected light intensity value to the control module; The control module determines whether the light source drifts according to the detected light intensity value, and if so, calibrates the light source.

7. The method according to claim 6, characterized in that Judging whether the light source drifts according to the detected light intensity value includes: Determining whether the light intensity value is within a preset threshold range; If yes, it is determined that the light source does not drift; If not, it is determined that the light source is drifting.

8. The method according to claim 6 or 7, characterized in that: Calibrating the light source comprises: Fine-tuning the temperature of the light source; Alternatively, the light source is subjected to delay fine adjustment and temperature fine adjustment.

9. The method according to claim 8, characterized in that Fine-tuning the temperature of the light source comprises: adjusting the temperature of the light source, and judging whether the light source drifts according to the light intensity value detected by the detector; If yes, continue to adjust the temperature of the light source until it is determined that the light source has not drifted according to the light intensity value detected by the detector; If not, end the calibration process.

10. The method according to claim 8, characterized in that The light source is subjected to time delay fine adjustment and temperature fine adjustment, including: Adjusting the delay value of the light source, and judging whether the light source drifts according to the light intensity value detected by the detector; If yes, adjust the temperature of the light source, and if the light source is still determined to have drifted according to the light intensity value detected by the detector, adjust the delay value of the light source, and repeat this process until the light source is determined to have not drifted according to the light intensity value detected by the detector; If not, end the calibration process.

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