Method and system for optimizing frequency modulation linearity of a laser

Abstract

The present disclosure provides a method and system for optimizing frequency modulation linearity of a laser, the method comprising: loading a first driving signal on a gain chip by a first driving voltage varying with time sequence, and not loading a signal on an external cavity chip, so that the laser outputs a first optical signal; loading a second driving signal on the external cavity chip by a second driving voltage varying with time sequence, and not loading the first driving signal on the gain chip, so that the laser outputs a second optical signal; processing the first optical signal and the second optical signal by a wavemeter, respectively, to obtain a first frequency modulation curve and a second frequency modulation curve corresponding to the first optical signal and the second optical signal, respectively; determining a first target driving signal and a second target driving signal according to the first frequency modulation curve and the second frequency modulation curve; and adjusting an output tuning curve of the laser based on the first target driving signal and the second target driving signal, so that the laser outputs a target optical signal with optimized output linearity.

Description

Technical Field

[0001] This disclosure relates to the field of laser technology, and more specifically, to a method and system for optimizing the frequency modulation linearity of a laser. Background Technology

[0002] Linear frequency modulated lasers have important applications in fields such as lidar, coherent optical communication, and optical coherence tomography. These fields not only require light sources with narrow linewidths, but also require ultra-high linearity within the frequency modulation range.

[0003] Currently used tunable narrow-linewidth lasers have low frequency modulation linearity and require further optimization. The tuning process of external cavity lasers based on discrete optical components is related to the jitter of the mechanical rotation of the microprocessor structure. This method results in slow tuning speeds and is easily affected by external environmental factors, severely reducing the reliability and frequency modulation accuracy of the laser. Summary of the Invention

[0004] In view of this, embodiments of the present disclosure provide a method for optimizing the frequency modulation linearity of a laser and a system for optimizing the frequency modulation linearity of a laser.

[0005] One aspect of this disclosure provides a method for optimizing the frequency modulation linearity of a laser, the laser including a gain chip and an external cavity chip, the method comprising:

[0006] A first driving signal is applied to the gain chip by a first driving voltage that changes with time, while no signal is applied to the external cavity chip, so that the laser outputs a first optical signal whose wavelength changes with the first driving voltage.

[0007] By applying a second driving voltage that varies with time, a second driving signal is applied to the external cavity chip, while the first driving signal is not applied to the gain chip, so that the laser outputs a second optical signal whose wavelength varies with the second driving voltage.

[0008] The first optical signal and the second optical signal are processed using a wavelength meter to obtain a first frequency modulation curve and a second frequency modulation curve corresponding to the first optical signal and the second optical signal, respectively.

[0009] Based on the nonlinear characteristics of the first frequency modulation curve and the second frequency modulation curve, the first target driving signal and the second target driving signal are determined.

[0010] The output tuning curve of the laser is adjusted based on the first target driving signal and the second target driving signal to optimize the linearity of the laser output target light signal.

[0011] According to embodiments of this disclosure, determining the first target driving signal and the second target driving signal based on the nonlinear characteristics of the first frequency modulation curve and the second frequency modulation curve includes:

[0012] By fitting the first frequency modulation curve and the second frequency modulation curve respectively, two second-order linear equations are obtained that characterize the nonlinear characteristics of the first frequency modulation curve and the second frequency modulation curve respectively.

[0013] Based on the two aforementioned second-order linear equations, the aforementioned first driving signal, and the aforementioned second driving signal, the aforementioned first target driving signal and the aforementioned second target driving signal are generated.

[0014] According to embodiments of this disclosure, generating the first target driving signal and the second target driving signal based on the two second-order linear equations, the first driving signal, and the second driving signal includes:

[0015] Extract the second-order coefficients of the two second-order linear equations mentioned above to obtain the first coefficient and the second coefficient;

[0016] Determine the proportionality coefficient between the first coefficient and the second coefficient mentioned above;

[0017] Based on the aforementioned proportional coefficient, the aforementioned first driving signal, and the aforementioned second driving signal, the aforementioned first target driving signal and the aforementioned second target driving signal are generated.

[0018] According to embodiments of this disclosure, generating the first target drive signal and the second target drive signal based on the scaling factor, the first drive signal, and the second drive signal includes:

[0019] Based on the preset adjustment rules, the first adjustment coefficient and the second adjustment coefficient of the first driving signal and the second driving signal are determined according to the above proportional coefficients respectively.

[0020] The first target driving signal is generated based on the first adjustment coefficient and the first driving signal.

[0021] The second target driving signal is generated based on the second adjustment coefficient and the second driving signal.

[0022] According to embodiments of this disclosure, adjusting the output tuning curve of the laser based on the first target driving signal and the second target driving signal to achieve a target light signal with optimized linearity output by the laser includes:

[0023] When the laser is working, the first target driving signal and the second target driving signal are respectively loaded on the gain chip and the external cavity chip, and the laser outputs the target light signal.

[0024] According to embodiments of this disclosure, the method for optimizing the linearity of a laser further includes:

[0025] The target optical signal was processed using the aforementioned wavelength meter to obtain the calibration frequency modulation curve;

[0026] Based on the above-mentioned verification frequency modulation curve, at least one of the above-mentioned first target driving signal and the above-mentioned second target driving signal is verified and adjusted to obtain at least one of the new first target driving signal and the new second target driving signal.

[0027] The output tuning curve of the laser is adjusted again based on at least one of the new first target driving signal and the new second target driving signal, and the laser outputs the adjusted target light signal.

[0028] According to embodiments of this disclosure, the above-mentioned calibration and adjustment of at least one of the first target driving signal and the second target driving signal based on the above-mentioned calibration frequency modulation curve to obtain at least one of the new first target driving signal and the new second target driving signal includes:

[0029] Based on the above-mentioned frequency modulation curve, determine the linearity fluctuation range;

[0030] If the linearity fluctuation range does not meet the fluctuation threshold, the calibration adjustment coefficient shall be determined based on the calibration frequency curve.

[0031] Based on the above-mentioned verification and adjustment coefficients, at least one of the above-mentioned first target driving signal and the above-mentioned second target driving signal is verified and adjusted to obtain at least one of the new first target driving signal and the new second target driving signal.

[0032] According to embodiments of this disclosure, determining the calibration adjustment coefficient based on the calibration frequency modulation curve includes:

[0033] Based on the preset coefficient gradient rule, the gradient coefficient representing the above-mentioned calibration adjustment coefficient is determined according to the above-mentioned calibration frequency modulation curve.

[0034] According to embodiments of this disclosure, determining the calibration adjustment coefficient based on the calibration frequency modulation curve includes:

[0035] Based on the above-mentioned calibration frequency modulation curve, determine the target slope of the above-mentioned calibration frequency modulation curve;

[0036] Based on the target slope and the reference slope of the reference frequency modulation curve, the slope ratio is determined, where the slope ratio represents the above-mentioned verification adjustment coefficient.

[0037] Another aspect of this disclosure provides a linearity optimization system for a laser, comprising:

[0038] The first voltage loading device is used to output a first driving signal corresponding to a first driving voltage that changes with time.

[0039] The second voltage loading device is used to output a second driving signal corresponding to the second driving voltage that changes with time.

[0040] A laser, wherein the laser is used to output a first optical signal, a second optical signal, and a target optical signal, and wherein the laser is used to adjust the output tuning curve based on the first target driving signal and the second target driving signal to output a target optical signal with optimized linearity, the laser comprising:

[0041] A gain chip is used to make the first optical signal whose output wavelength changes with the first driving voltage when a first driving signal is applied and no signal is applied to the external cavity chip.

[0042] The aforementioned external cavity chip is used to generate a second optical signal whose output wavelength varies with the aforementioned second driving voltage when the second driving signal is applied and the aforementioned gain chip is not applied to the first driving signal.

[0043] A wavelength meter is used to process the first optical signal and the second optical signal to obtain a first frequency modulation curve and a second frequency modulation curve corresponding to the first optical signal and the second optical signal, respectively.

[0044] The central processing unit is used to determine the first target driving signal and the second target driving signal based on the nonlinear characteristics of the first frequency modulation curve and the second frequency modulation curve.

[0045] Another aspect of this disclosure provides an electronic device, including: one or more processors; and a memory for storing one or more programs, wherein, when the one or more programs are executed by the one or more processors, the one or more processors cause the one or more processors to implement the method described above.

[0046] Another aspect of this disclosure provides a computer-readable storage medium storing computer-executable instructions that, when executed, are used to implement the method described above.

[0047] Another aspect of this disclosure provides a computer program product including computer-executable instructions that, when executed, implement the method described above.

[0048] According to embodiments of this disclosure, by applying a driving signal to the gain chip and the external cavity chip respectively, and processing the two optical signals output by the laser using a wavelength meter, two frequency modulation curves can be obtained respectively. Based on the two frequency modulation curves, two target driving signals can be determined. By applying the two target driving signals to the gain chip and the external cavity chip respectively, a frequency-modulated target optical signal with better linearity can be obtained. Therefore, the technical problem of low linearity of the laser, which reduces the detection accuracy of the laser, is at least partially overcome, thereby achieving the technical effect of improving the frequency modulation linearity and accuracy of the laser. Attached Figure Description

[0049] The above and other objects, features and advantages of this disclosure will become clearer from the following description of embodiments with reference to the accompanying drawings, in which:

[0050] Figure 1 A flowchart illustrating a method for optimizing the frequency modulation linearity of a laser according to an embodiment of the present disclosure is shown schematically.

[0051] Figure 2 This illustration schematically shows the effect of the frequency modulation linearity optimization method according to an embodiment of the present disclosure;

[0052] Figure 3 A block diagram of a laser according to an embodiment of the present disclosure is shown schematically;

[0053] Figure 4 A block diagram of a frequency modulation linearity optimization system according to an embodiment of the present disclosure is illustrated schematically; and

[0054] Figure 5 A block diagram of an electronic device suitable for implementing the methods described above, according to embodiments of the present disclosure, is illustrated schematically. Detailed Implementation

[0055] The embodiments of the present disclosure will now be described with reference to the accompanying drawings. However, it should be understood that these descriptions are exemplary only and are not intended to limit the scope of the disclosure. In the following detailed description, numerous specific details are set forth to provide a thorough understanding of the embodiments of the present disclosure for ease of explanation. However, it will be apparent that one or more embodiments may be practiced without these specific details. Furthermore, descriptions of well-known structures and techniques are omitted in the following description to avoid unnecessarily obscuring the concepts of the present disclosure.

[0056] The terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit this disclosure. The terms “comprising,” “including,” etc., as used herein indicate the presence of the stated features, steps, operations, and / or components, but do not exclude the presence or addition of one or more other features, steps, operations, or components.

[0057] All terms used herein (including technical and scientific terms) have the meanings commonly understood by those skilled in the art, unless otherwise defined. It should be noted that the terms used herein are to be interpreted in a manner consistent with the context of this specification, and not in an idealized or overly rigid way.

[0058] When using expressions such as "at least one of A, B, and C", they should generally be interpreted in accordance with the meaning that is commonly understood by a person skilled in the art (e.g., "a system having at least one of A, B, and C" should include, but is not limited to, a system having A alone, a system having B alone, a system having C alone, a system having A and B, a system having A and C, a system having B and C, and / or a system having A, B, and C, etc.).

[0059] Figure 1 A flowchart illustrating a method for optimizing the frequency modulation linearity of a laser according to an embodiment of the present disclosure is shown.

[0060] Lasers can include gain chips and external cavity chips, such as Figure 1 As shown, the method for optimizing the frequency modulation linearity of a laser may include operations S101 to S105.

[0061] In operation S101, a first driving signal is applied to the gain chip by a first driving voltage that changes with time, while no signal is applied to the external cavity chip, so that the laser outputs a first optical signal whose wavelength changes with the first driving voltage.

[0062] In operation S102, a second driving signal is applied to the external cavity chip by a second driving voltage that changes with time, while the gain chip is not loaded with the first driving signal, so that the laser outputs a second optical signal whose wavelength changes with the second driving voltage.

[0063] In operation S103, the first optical signal and the second optical signal are processed by a wavelength meter to obtain the first frequency modulation curve and the second frequency modulation curve corresponding to the first optical signal and the second optical signal, respectively.

[0064] In operation S104, the first target driving signal and the second target driving signal are determined based on the nonlinear characteristics of the first frequency modulation curve and the second frequency modulation curve.

[0065] In operation S105, the output tuning curve of the laser is adjusted based on the first target driving signal and the second target driving signal so that the laser outputs a target light signal with optimized linearity.

[0066] According to embodiments of this disclosure, the first driving signal and the second driving signal can be applied to the gain chip and the external cavity chip by an external device, and the two driving signals change with the corresponding voltage. The laser of this disclosure can be a linearly frequency-modulated external cavity laser.

[0067] According to embodiments of this disclosure, a wavelength meter is an instrument that measures the wavelength of an optical signal using the resonance phenomenon. Wavelength meters typically utilize the resonant characteristics of a resonant cavity to accurately and rapidly measure the wavelength of an optical signal. Wavelength meters with an accuracy on the order of 10 MHz or higher can be used.

[0068] According to embodiments of this disclosure, a driving signal is applied to both the gain chip and the external cavity chip within a preset time period. It should be noted that while a driving signal is applied to one chip, no driving signal is applied to the other chip. At this time, the laser can output a first optical signal and a second optical signal accordingly. After receiving the first or second optical signal, the wavelength meter can obtain the frequency modulation curve of the corresponding optical signal. Based on the nonlinear characteristics of the first and second frequency modulation curves corresponding to the first and second optical signals, respectively, the first target driving signal and the second target driving signal can be determined. These two target driving signals are then synchronously applied to the gain chip and the external cavity chip, thereby enabling the laser to output a target optical signal with optimized linearity.

[0069] It should be noted that by loading two target driving signals onto the gain chip and the external cavity chip respectively, the original nonlinearity can be compensated by the change of the laser's output wavelength with the driving signal, thereby optimizing the linearity of the laser and obtaining a more linear target linear frequency modulation curve. At this time, using the target optical signal corresponding to the target linear frequency modulation curve for detection can obtain more accurate detection results.

[0070] According to embodiments of this disclosure, by applying a driving signal to the gain chip and the external cavity chip respectively, and processing the two optical signals output by the laser using a wavelength meter, two frequency modulation curves can be obtained respectively. Based on the two frequency modulation curves, two target driving signals can be determined. By applying the two target driving signals to the gain chip and the external cavity chip respectively, a frequency-modulated target optical signal with better linearity can be obtained. Therefore, the technical problem of low linearity of the laser, which reduces the detection accuracy of the laser, is at least partially overcome, thereby achieving the technical effect of improving the frequency modulation linearity and accuracy of the laser.

[0071] Figure 2 The illustration shows a schematic diagram of the effect of the frequency modulation linearity optimization method according to an embodiment of the present disclosure.

[0072] According to embodiments of this disclosure, determining the first target driving signal and the second target driving signal based on the nonlinear characteristics of the first frequency modulation curve and the second frequency modulation curve may include the following operations:

[0073] By fitting the first frequency modulation curve and the second frequency modulation curve respectively, two second-order linear equations are obtained that characterize the nonlinear features of the first frequency modulation curve and the second frequency modulation curve respectively.

[0074] Based on two second-order linear equations, the first driving signal, and the second driving signal, the first target driving signal and the second target driving signal are generated.

[0075] According to embodiments of this disclosure, in the coordinate system containing the frequency modulation curve, the horizontal axis represents time, and the vertical axis represents the frequency of the optical signal.

[0076] According to embodiments of this disclosure, respectively for such Figure 2 The first frequency modulation curve f1 and the second frequency modulation curve f2 shown are fitted to obtain two second-order linear equations f1(s1) and f2(s2) that characterize the nonlinear characteristics of the first frequency modulation curve and the second frequency modulation curve, respectively, as shown in formula (1) and formula (2).

[0077] f1(s1)=k 11 s1+k 12 s1 2 (1)

[0078] f2(s2)=k 21 s2+k 22 s2 2 (2)

[0079] Wherein, s1 and s2 are the first driving voltage and the second driving voltage, respectively; k 11 and k 21 The first-order coefficients of the two equations are k and k, respectively. 12 and k 22 These are the second-order coefficients of the two equations, respectively.

[0080] According to embodiments of this disclosure, after determining two second-order linear equations, a first target driving signal and a second target driving signal can be generated by combining the first driving signal and the second driving signal. After simultaneously loading the first target driving signal and the second target driving signal onto the gain chip and the external cavity chip, respectively, the laser can output a target light signal with good linearity. The frequency modulation curve of the target light signal is shown in the figure below. Figure 2 The f3 curve in the image.

[0081] According to embodiments of this disclosure, generating a first target driving signal and a second target driving signal based on two second-order linear equations, a first driving signal, and a second driving signal may include the following operations:

[0082] Extract the second-order coefficients from the two second-order linear equations to obtain the first coefficient and the second coefficient. Determine the scaling factor between the first and second coefficients. Based on the scaling factor, the first driving signal, and the second driving signal, generate the first target driving signal and the second target driving signal.

[0083] According to embodiments of this disclosure, after determining two second-order linear equations, the second-order coefficients in each equation are extracted to obtain the first coefficient k. 12 Second coefficient k 22 Thus, the first coefficient k is determined. 12 Second coefficient k 22 The proportional coefficient between the two signals is used to adjust the first drive signal and the second drive signal, thereby obtaining the first target drive signal and the second target drive signal.

[0084] According to embodiments of this disclosure, generating a first target drive signal and a second target drive signal based on a scaling factor, a first drive signal, and a second drive signal may include the following operations:

[0085] Based on preset adjustment rules, the first adjustment coefficient and the second adjustment coefficient of the first drive signal and the second drive signal are determined according to the proportional coefficient.

[0086] A first target drive signal is generated based on a first adjustment coefficient and a first drive signal.

[0087] A second target driving signal is generated based on the second adjustment coefficient and the second driving signal.

[0088] In one exemplary embodiment, it is assumed that the ratio between the first coefficient and the second coefficient is... The preset adjustment rule can refer to a preset multiple of the first adjustment coefficient being n and a preset multiple of the second adjustment coefficient being m, where the preset multiple can be any value.

[0089] In another exemplary embodiment, the preset adjustment rule may refer to a first adjustment coefficient and a second adjustment coefficient, one of which is the reciprocal of the proportional coefficient, and the other adjustment coefficient is 1.

[0090] According to embodiments of this disclosure, after the first adjustment coefficient and the second adjustment coefficient are determined, the first driving signal and the second driving signal are adjusted using the first adjustment coefficient and the second adjustment coefficient respectively, thereby obtaining the first target driving signal and the second target driving signal.

[0091] According to embodiments of this disclosure, adjusting the output tuning curve of the laser based on a first target driving signal and a second target driving signal to achieve a target light signal with optimized laser output linearity may include the following operations:

[0092] When the laser is working, a first target driving signal and a second target driving signal are loaded on the gain chip and the external cavity chip, respectively, and the laser outputs the target light signal.

[0093] According to embodiments of this disclosure, after determining the first target driving signal and the second target driving signal, the two target driving signals are loaded onto the gain chip and the external cavity chip respectively, so that the laser outputs a target light signal with optimized linearity.

[0094] According to embodiments of this disclosure, the laser frequency modulation linearity optimization method may further include the following operations:

[0095] The target optical signal is processed using a wavelength meter to obtain the calibration frequency modulation curve.

[0096] Based on the calibration frequency modulation curve, at least one of the first target driving signal and the second target driving signal is calibrated and adjusted to obtain at least one of the new first target driving signal and the new second target driving signal.

[0097] The laser's output tuning curve is readjusted based on at least one of the new first target driving signal and the new second target driving signal, and the laser output is verified to adjust the target light signal.

[0098] According to embodiments of this disclosure, since the frequency modulation curve of the target optical signal after linearity optimization may not meet the requirements, verification is required to determine whether the target optical signal can be used for detection.

[0099] According to an embodiment of this disclosure, after the target light signal output by the laser is processed by a wavelength meter, a corresponding calibration frequency modulation curve is obtained. Based on the calibration frequency modulation curve, it is determined whether the linearity of the target light signal meets the requirements. If the requirements are not met, at least one of the first target driving signal and the second target driving signal is recalibrated and adjusted so that the laser generates a target light signal with linearity that meets the requirements based on at least one of the new first target driving signal and the new second target driving signal.

[0100] According to embodiments of this disclosure, based on a calibration frequency modulation curve, at least one of a first target driving signal and a second target driving signal is calibrated and adjusted to obtain at least one of a new first target driving signal and a new second target driving signal. This may include the following operations:

[0101] Based on the calibration frequency curve, determine the linearity fluctuation range.

[0102] If the linearity fluctuation range does not meet the fluctuation threshold, the calibration adjustment coefficient is determined based on the calibration frequency modulation curve.

[0103] Based on the verification adjustment coefficient, at least one of the first target driving signal and the second target driving signal is verified and adjusted to obtain at least one of the new first target driving signal and the new second target driving signal.

[0104] According to embodiments of this disclosure, the linearity fluctuation range and fluctuation threshold can be specifically set according to actual conditions, wherein the linearity fluctuation range characterizes the smoothness of the calibration frequency curve.

[0105] According to embodiments of this disclosure, when a calibration frequency modulation curve is obtained, the linearity fluctuation range of the calibration frequency modulation is determined, thereby determining whether the linearity fluctuation range is within a fluctuation threshold. If it exceeds the fluctuation threshold, a calibration adjustment coefficient is determined based on the calibration frequency modulation curve, and the calibration adjustment coefficient is used to perform calibration adjustment on at least one of the first target driving signal and the second target driving signal to obtain at least one of the new first target driving signal and the new second target driving signal. Then, the new target driving signal is loaded onto the laser so that the laser outputs a target light signal with linearity that meets the requirements.

[0106] According to embodiments of this disclosure, determining the calibration adjustment coefficient based on the calibration frequency modulation curve may include the following operations:

[0107] Based on the preset coefficient gradient rule, the gradient coefficients characterizing the calibration adjustment coefficients are determined according to the calibration frequency modulation curve.

[0108] According to embodiments of this disclosure, the preset coefficient gradient rule can refer to adjusting the coefficient by increasing or decreasing the gradient.

[0109] In one exemplary embodiment, when the calibration frequency modulation curve does not meet the requirements, based on the curvature of the calibration frequency modulation curve—for example, if the calibration frequency modulation curve bends upwards, i.e., the center of the arc is below the calibration frequency modulation curve—0.8 can be determined as a gradient coefficient. This gradient coefficient, along with the previous target driving signal, is used to determine the latest target driving signal, ensuring that the laser outputs a target optical signal with the required linearity. If the output target optical signal also fails to meet the requirements, a new gradient coefficient, such as 0.9, can be determined based on the calibration frequency modulation curve corresponding to the current output target optical signal. This new gradient coefficient, along with the previous target driving signal, is then used to determine a new target driving signal. This process iteratively determines the target driving signal until the final laser outputs a target optical signal with the required linearity.

[0110] It should be noted that the specific values ​​mentioned above are for illustrative purposes only and may be other values, and are not intended to limit the scope of protection of this disclosure.

[0111] According to embodiments of this disclosure, determining the calibration adjustment coefficient based on the calibration frequency modulation curve may include the following operations:

[0112] Based on the calibration frequency modulation curve, determine the target slope of the calibration frequency modulation curve.

[0113] Based on the target slope and the reference slope of the reference frequency modulation curve, the slope ratio is determined, where the slope ratio characterizes the verification adjustment coefficient.

[0114] In another exemplary embodiment, the tangent between the calibration frequency modulation curve and the origin of the coordinate system can be determined, and the slope of the tangent can be determined as the target slope. Then, the slope ratio between the two slopes is combined with the reference slope of the reference frequency modulation curve, and the previous target drive signal is adjusted using the slope ratio to generate a new target drive signal.

[0115] Figure 3 A block diagram of a laser according to an embodiment of the present disclosure is shown schematically.

[0116] like Figure 3 As shown, the laser may include a gain chip and an external cavity chip. The optical signal generated by the gain chip can be output as an optical signal after passing through the external cavity chip. The external cavity chip may include a phase modulation region and a filtering structure. The phase modulation region is used to load a second driving signal, and the filtering structure is used to filter the optical signal, thereby outputting a filtered optical signal.

[0117] Figure 4 A block diagram of a frequency modulation linearity optimization system according to an embodiment of the present disclosure is illustrated.

[0118] like Figure 4 As shown, the linearity optimization system for the laser may include a first voltage loading device 410, a second voltage loading device 420, a laser 430, a wavelength meter 440, and a central processing unit 450.

[0119] The first voltage loading device 410 is used to output a first driving signal corresponding to the first driving voltage that changes with time.

[0120] The second voltage loading device 420 is used to output a second driving signal corresponding to the second driving voltage that changes with time.

[0121] Laser 430 is used to output a first optical signal, a second optical signal and a target optical signal. The laser is used to adjust the output tuning curve based on the first target driving signal and the second target driving signal to output a target optical signal with optimized linearity. The laser may include a gain chip 431 and an external cavity chip 432.

[0122] Gain chip 431 is used to make the laser output wavelength change with the first driving voltage when the first driving signal is applied and the external cavity chip is not loaded with a signal.

[0123] The external cavity chip 432 is used to make the laser output wavelength change with the second driving voltage when the second driving signal is applied and the gain chip is not applied with the first driving signal.

[0124] Wavelength meter 440 is used to process the first optical signal and the second optical signal to obtain the first frequency modulation curve and the second frequency modulation curve corresponding to the first optical signal and the second optical signal, respectively.

[0125] The central processing unit 450 is used to determine the first target driving signal and the second target driving signal based on the nonlinear characteristics of the first frequency modulation curve and the second frequency modulation curve.

[0126] According to embodiments of this disclosure, both the first voltage loading device 410 and the second voltage loading device 420 can be voltage controllers.

[0127] According to embodiments of this disclosure, by applying a driving signal to the gain chip and the external cavity chip respectively, and processing the two optical signals output by the laser using a wavelength meter, two frequency modulation curves can be obtained respectively. Based on the two frequency modulation curves, two target driving signals can be determined. By applying the two target driving signals to the gain chip and the external cavity chip respectively, a frequency-modulated target optical signal with better linearity can be obtained. Therefore, the technical problem of low linearity of the laser, which reduces the detection accuracy of the laser, is at least partially overcome, thereby achieving the technical effect of improving the frequency modulation linearity and accuracy of the laser.

[0128] According to embodiments of this disclosure, the central processing unit 450 can be used for:

[0129] By fitting the first frequency modulation curve and the second frequency modulation curve respectively, two second-order linear equations are obtained that characterize the nonlinear features of the first frequency modulation curve and the second frequency modulation curve respectively.

[0130] Based on two second-order linear equations, the first driving signal, and the second driving signal, the first target driving signal and the second target driving signal are generated.

[0131] According to embodiments of this disclosure, generating a first target driving signal and a second target driving signal based on two second-order linear equations, a first driving signal, and a second driving signal includes:

[0132] Extract the second-order coefficients of the two second-order linear equations to obtain the first and second coefficients.

[0133] Determine the proportionality coefficient between the first coefficient and the second coefficient.

[0134] Based on the proportional coefficient, the first driving signal, and the second driving signal, a first target driving signal and a second target driving signal are generated.

[0135] According to embodiments of this disclosure, generating a first target drive signal and a second target drive signal based on a scaling factor, a first drive signal, and a second drive signal includes:

[0136] Based on preset adjustment rules, the first adjustment coefficient and the second adjustment coefficient of the first drive signal and the second drive signal are determined according to the proportional coefficient.

[0137] A first target drive signal is generated based on a first adjustment coefficient and a first drive signal.

[0138] A second target driving signal is generated based on the second adjustment coefficient and the second driving signal.

[0139] According to embodiments of this disclosure, the wavelength meter is also used to process the target optical signal to obtain a calibration frequency modulation curve.

[0140] According to embodiments of this disclosure, the linearity optimization system may further include a verification and adjustment device. The verification and adjustment device may include an acquisition module and an adjustment module.

[0141] The module is used to perform verification and adjustment on at least one of the first target drive signal and the second target drive signal based on the verification frequency modulation curve, so as to obtain at least one of the new first target drive signal and the new second target drive signal.

[0142] The adjustment module is used to readjust the output tuning curve of the laser based on at least one of the new first target driving signal and the new second target driving signal, and the laser output verifies the adjusted target light signal.

[0143] According to embodiments of this disclosure, the obtaining module may include a first determining unit, a second determining unit, and a first obtaining unit.

[0144] The first determining unit is used to determine the linearity fluctuation range based on the calibration frequency curve.

[0145] The second determining unit is used to determine the calibration adjustment coefficient based on the calibration frequency curve when the linearity fluctuation range does not meet the fluctuation threshold.

[0146] The first obtaining unit is used to perform verification and adjustment on at least one of the first target driving signal and the second target driving signal based on the verification adjustment coefficient, so as to obtain at least one of the new first target driving signal and the new second target driving signal.

[0147] According to embodiments of this disclosure, the second determining unit may include the first determining subunit.

[0148] The first determining subunit is used to determine the gradient coefficients that characterize the calibration adjustment coefficients based on the preset coefficient gradient rules and the calibration frequency modulation curve.

[0149] According to embodiments of this disclosure, the second determining unit may further include a second determining subunit and a third determining subunit.

[0150] The second determining subunit is used to determine the target slope of the calibration frequency modulation curve based on the calibration frequency modulation curve.

[0151] The third determining subunit is used to determine the slope ratio based on the target slope and the reference slope of the reference frequency modulation curve, wherein the slope ratio characterizes the verification adjustment coefficient.

[0152] Any one or more of the modules, units, and subunits according to embodiments of the present disclosure, or at least part of the functions of any one or more of them, can be implemented in one module. Any one or more of the modules, units, and subunits according to embodiments of the present disclosure can be implemented by dividing them into multiple modules. Any one or more of the modules, units, and subunits according to embodiments of the present disclosure can be at least partially implemented as hardware circuits, such as Field Programmable Gate Arrays (FPGAs), Programmable Logic Arrays (PLAs), Systems-on-Chip, Systems-on-Substrate, Systems-on-Package, Application-Specific Integrated Circuits (ASICs), or implemented by hardware or firmware through any other reasonable means of integrating or packaging circuits, or implemented in software, hardware, or firmware, or in a suitable combination of any of these three implementation methods. Alternatively, one or more of the modules, units, and subunits according to embodiments of the present disclosure can be at least partially implemented as computer program modules, which, when run, can perform corresponding functions.

[0153] It should be noted that the linearity optimization system part in the embodiments of this disclosure corresponds to the frequency modulation linearity optimization method part in the embodiments of this disclosure. For a detailed description of the linearity optimization system part, please refer to the frequency modulation linearity optimization method part, which will not be repeated here.

[0154] Figure 5 A block diagram of an electronic device suitable for implementing the methods described above, according to embodiments of the present disclosure, is illustrated schematically. Figure 5 The electronic device shown is merely an example and should not be construed as limiting the functionality and scope of the embodiments disclosed herein.

[0155] like Figure 5 As shown, an electronic device 500 according to an embodiment of the present disclosure includes a processor 501, which can perform various appropriate actions and processes according to a program stored in read-only memory (ROM) 502 or a program loaded from storage portion 508 into random access memory (RAM) 503. The processor 501 may include, for example, a general-purpose microprocessor (e.g., a CPU), an instruction set processor and / or an associated chipset and / or a special-purpose microprocessor (e.g., an application-specific integrated circuit (ASIC)), etc. The processor 501 may also include onboard memory for caching purposes. The processor 501 may include a single processing subunit or multiple processing subunits for performing different actions of the method flow according to an embodiment of the present disclosure.

[0156] RAM 503 stores various programs and data required for the operation of electronic device 500. Processor 501, ROM 502, and RAM 503 are interconnected via bus 504. Processor 501 performs various operations of the method flow according to embodiments of the present disclosure by executing programs in ROM 502 and / or RAM 503. It should be noted that the programs may also be stored in one or more memories other than ROM 502 and RAM 503. Processor 501 may also perform various operations of the method flow according to embodiments of the present disclosure by executing programs stored in said one or more memories.

[0157] According to embodiments of this disclosure, the electronic device 500 may further include an input / output (I / O) interface 505, which is also connected to a bus 504. The system 500 may also include one or more of the following components connected to the I / O interface 505: an input section 506 including a keyboard, mouse, etc.; an output section 507 including a cathode ray tube (CRT), liquid crystal display (LCD), etc., and a speaker, etc.; a storage section 508 including a hard disk, etc.; and a communication section 509 including a network interface card such as a LAN card, modem, etc. The communication section 509 performs communication processing via a network such as the Internet. A drive 510 is also connected to the I / O interface 505 as needed. A removable medium 511, such as a disk, optical disk, magneto-optical disk, semiconductor memory, etc., is installed on the drive 510 as needed so that computer programs read from it can be installed into the storage section 508 as needed.

[0158] According to embodiments of this disclosure, the method flow according to embodiments of this disclosure can be implemented as a computer software program. For example, embodiments of this disclosure include a computer program product comprising a computer program carried on a computer-readable storage medium, the computer program containing program code for performing the methods shown in the flowchart. In such embodiments, the computer program can be downloaded and installed from a network via communication section 509, and / or installed from removable medium 511. When the computer program is executed by processor 501, it performs the functions defined in the system of embodiments of this disclosure. According to embodiments of this disclosure, the systems, devices, apparatuses, modules, sub-units, etc., described above can be implemented by computer program modules.

[0159] This disclosure also provides a computer-readable storage medium, which may be included in the device / apparatus / system described in the above embodiments; or it may exist independently and not assembled into the device / apparatus / system. The computer-readable storage medium carries one or more programs that, when executed, implement the method according to the embodiments of this disclosure.

[0160] According to embodiments of this disclosure, the computer-readable storage medium can be a non-volatile computer-readable storage medium. Examples include, but are not limited to: portable computer disks, hard disks, random access memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EPROM or flash memory), portable compact disk read-only memory (CD-ROM), optical storage devices, magnetic storage devices, or any suitable combination thereof. In this disclosure, the computer-readable storage medium can be any tangible medium that contains or stores a program that can be used by or in conjunction with an instruction execution system, apparatus, or device.

[0161] For example, according to embodiments of this disclosure, a computer-readable storage medium may include the ROM 502 and / or RAM 503 described above and / or one or more memories other than ROM 502 and RAM 503.

[0162] Embodiments of this disclosure also include a computer program product comprising a computer program containing program code for performing the methods provided in the embodiments of this disclosure. When the computer program product is run on an electronic device, the program code is used to enable the electronic device to implement the frequency modulation linearity optimization method provided in the embodiments of this disclosure.

[0163] When the computer program is executed by the processor 501, it performs the functions defined in the system / apparatus of this disclosure. According to embodiments of this disclosure, the systems, apparatuses, modules, sub-units, etc., described above can be implemented by computer program modules.

[0164] In one embodiment, the computer program may rely on a tangible storage medium such as an optical storage device or a magnetic storage device. In another embodiment, the computer program may also be transmitted and distributed in the form of signals over a network medium, and may be downloaded and installed via the communication section 509, and / or installed from a removable medium 511. The program code contained in the computer program can be transmitted using any suitable network medium, including but not limited to: wireless, wired, etc., or any suitable combination thereof.

[0165] According to embodiments of this disclosure, program code for executing the computer programs provided in embodiments of this disclosure can be written in any combination of one or more programming languages. Specifically, these computational programs can be implemented using high-level procedural and / or object-oriented programming languages, and / or assembly / machine languages. Programming languages ​​include, but are not limited to, languages ​​such as Java, C++, Python, "C", or similar programming languages. The program code can execute entirely on the user's computing device, partially on the user's device, partially on a remote computing device, or entirely on a remote computing device or server. In cases involving remote computing devices, the remote computing device can be connected to the user's computing device via any type of network, including a local area network (LAN) or a wide area network (WAN), or it can be connected to an external computing device (e.g., via the Internet using an Internet service provider).

[0166] The electronic device disclosed herein can be controlled by a computer program to apply a first driving signal and a second driving signal to the gain chip 431 and the external cavity chip 432, respectively. The computer program can also control a wavelength meter 440 to process each of the first optical signal, the second optical signal, and the target optical signal output by the laser 430. The computer program can also control the determination of the target driving signal based on the frequency modulation curve output by the wavelength meter 440, and apply the determined first target driving signal and the first target driving signal to the gain chip 431 and the external cavity chip 432, respectively, using the first voltage loading device 410 and the second voltage loading device 420.

[0167] The flowcharts and block diagrams in the accompanying drawings illustrate the architecture, functionality, and operation of possible implementations of systems, methods, and computer program products according to various embodiments of the present disclosure. In this regard, each block in a flowchart or block diagram may represent a module, segment, or portion of code containing one or more executable instructions for implementing a specified logical function. It should also be noted that in some alternative implementations, the functions indicated in the blocks may occur in a different order than those indicated in the drawings. For example, two consecutively indicated blocks may actually be executed substantially in parallel, and they may sometimes be executed in reverse order, depending on the functions involved. It should also be noted that each block in a block diagram or flowchart, and combinations of blocks in a block diagram or flowchart, may be implemented using a dedicated hardware-based system that performs the specified function or operation, or using a combination of dedicated hardware and computer instructions. Those skilled in the art will understand that the features recited in the various embodiments and / or claims of this disclosure can be combined and / or combined in various ways, even if such combinations or combinations are not expressly described in this disclosure. In particular, the features described in the various embodiments and / or claims of this disclosure may be combined and / or combined in various ways without departing from the spirit and teachings of this disclosure. All such combinations and / or combinations fall within the scope of this disclosure.

[0168] The embodiments of this disclosure have been described above. However, these embodiments are for illustrative purposes only and are not intended to limit the scope of this disclosure. Although various embodiments have been described above, this does not mean that the measures in the various embodiments cannot be used advantageously in combination. The scope of this disclosure is defined by the appended claims and their equivalents. Various substitutions and modifications can be made by those skilled in the art without departing from the scope of this disclosure, and all such substitutions and modifications should fall within the scope of this disclosure.

Claims

1. A method for optimizing the frequency modulation linearity of a laser, the laser comprising a gain chip and an external cavity chip, the method comprising: A first driving voltage that varies with time is used to apply a first driving signal to the gain chip, while no signal is applied to the external cavity chip, so that the laser outputs a first optical signal whose wavelength varies with the first driving voltage. By applying a second driving voltage that varies with time, a second driving signal is applied to the external cavity chip, while the first driving signal is not applied to the gain chip, so that the laser outputs a second optical signal whose wavelength varies with the second driving voltage. The first optical signal and the second optical signal are processed using a wavelength meter to obtain a first frequency modulation curve and a second frequency modulation curve corresponding to the first optical signal and the second optical signal, respectively. By fitting the first frequency modulation curve and the second frequency modulation curve respectively, two second-order linear equations are obtained that characterize the nonlinear features of the first frequency modulation curve and the second frequency modulation curve respectively. Extract the second-order coefficients of the two second-order linear equations respectively to obtain the first coefficient and the second coefficient; Determine the proportionality coefficient between the first coefficient and the second coefficient; Based on preset adjustment rules, the first adjustment coefficient and the second adjustment coefficient of the first drive signal and the second drive signal are determined according to the proportional coefficient, respectively. A first target driving signal is generated based on a first adjustment coefficient and a first driving signal; Based on the second adjustment coefficient and the second driving signal, a second target driving signal is generated; The output tuning curve of the laser is adjusted based on the first target driving signal and the second target driving signal so that the laser outputs a target light signal with optimized linearity.

2. The method of claim 1, wherein, The step of adjusting the output tuning curve of the laser based on the first target driving signal and the second target driving signal to make the laser output a target light signal with optimized linearity includes: When the laser is working, the first target driving signal and the second target driving signal are respectively loaded on the gain chip and the external cavity chip, and the laser outputs the target light signal.

3. The method according to claim 1, further comprising: The target optical signal is processed using the wavelength meter to obtain a calibration frequency modulation curve; Based on the verification frequency modulation curve, at least one of the first target driving signal and the second target driving signal is verified and adjusted to obtain at least one of the new first target driving signal and the new second target driving signal. The output tuning curve of the laser is readjusted again based on at least one of the new first target driving signal and the new second target driving signal, and the laser outputs the adjusted target light signal.

4. The method of claim 3, wherein, The step of performing verification and adjustment on at least one of the first target drive signal and the second target drive signal based on the verification frequency modulation curve to obtain at least one of the new first target drive signal and the new second target drive signal includes: Based on the aforementioned calibration frequency curve, determine the linearity fluctuation range; If the linearity fluctuation range does not meet the fluctuation threshold, the verification adjustment coefficient is determined according to the verification frequency modulation curve. Based on the verification adjustment coefficient, at least one of the first target driving signal and the second target driving signal is verified and adjusted to obtain at least one of the new first target driving signal and the new second target driving signal.

5. The method of claim 4, wherein, The step of determining the calibration adjustment coefficient based on the calibration frequency modulation curve includes: Based on the preset coefficient gradient rule, the gradient coefficient representing the verification adjustment coefficient is determined according to the verification frequency modulation curve.

6. The method of claim 4, wherein, The step of determining the calibration adjustment coefficient based on the calibration frequency modulation curve includes: Based on the calibration frequency modulation curve, determine the target slope of the calibration frequency modulation curve; Based on the target slope and the reference slope of the reference frequency modulation curve, a slope ratio is determined, wherein the slope ratio characterizes the verification adjustment coefficient.

7. A system for optimizing the frequency modulation linearity of a laser, comprising: The first voltage loading device is used to output a first driving signal corresponding to a first driving voltage that changes with time. The second voltage loading device is used to output a second driving signal corresponding to the second driving voltage that changes with time. A laser, wherein the laser is used to output a first optical signal, a second optical signal, and a target optical signal, and the laser is used to adjust the output tuning curve based on the first target driving signal and the second target driving signal to output a target optical signal with optimized linearity, the laser comprising: A gain chip is used to make the laser output a first optical signal whose wavelength changes with the first driving voltage when a first driving signal is applied and no signal is applied to the external cavity chip. The external cavity chip is used to make the laser output a second optical signal whose wavelength changes with the second driving voltage when the second driving signal is applied and the gain chip is not applied to the first driving signal; A wavelength meter is used to process the first optical signal and the second optical signal to obtain a first frequency modulation curve and a second frequency modulation curve corresponding to the first optical signal and the second optical signal, respectively. The central processing unit is used to fit the first frequency modulation curve and the second frequency modulation curve respectively to obtain two second-order linear equations that characterize the nonlinear features of the first frequency modulation curve and the second frequency modulation curve respectively; extract the second-order coefficients of the two second-order linear equations to obtain the first coefficient and the second coefficient; determine the proportional coefficient between the first coefficient and the second coefficient; determine the first adjustment coefficient and the second adjustment coefficient of the first drive signal and the second drive signal respectively according to the proportional coefficient based on the preset adjustment rule; generate the first target drive signal according to the first adjustment coefficient and the first drive signal; and generate the second target drive signal according to the second adjustment coefficient and the second drive signal.

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