Methods, systems and devices for tunable frequency stabilization of semiconductor lasers

Abstract

This invention relates to the field of laser technology and discloses a tunable frequency stabilization method, system, and apparatus for semiconductor lasers. The method includes: activating a seed source control of the semiconductor laser in response to a start command; adjusting the temperature of the seed source control to a first temperature and adjusting its current to a first current; controlling the photocurrent to be within the step range of the photodiode's nonlinear region in response to an adjustment operation of the seed source polarization beam splitter; applying sweep frequency modulation to the seed source control to extract the differential signal from the photodetector, and stabilizing the frequency based on the differential signal. This method adjusts the optical power received by the photodiode in the optical path system, causing the photodiode to reach the step range of the nonlinear region, and uses its output differential signal to stabilize the frequency of the laser amplified signal. This eliminates the Doppler broadening effect of saturated absorption frequency stabilization under detuning conditions, improves the frequency stability of the optical path system at specific application operating wavelengths, and reduces the complexity of the frequency-stabilized laser system.

Description

Technical Field

[0001] This invention relates to the field of laser technology, and more specifically to a tunable frequency stabilization method, system, and apparatus for semiconductor lasers. Background Technology

[0002] Spin-Exchange Relaxation-Free (SERF) atomic magnetometers are among the most sensitive magnetic field measurement technologies currently available. They have already been applied to measuring weak magnetic fields such as those in magnetocardiography and magnetoencephalography (MEG) and hold promise for widespread use in medical diagnostics, demonstrating irreplaceable advantages in several cutting-edge fields. The operation of SERF atomic magnetometers relies on the polarization and detection of alkali metal atoms, and the frequency stability of the semiconductor laser directly affects the atomic polarization efficiency and the detection signal-to-noise ratio. Therefore, researching and developing high-precision laser frequency stabilization technology is of great significance for improving the sensitivity and long-term stability of atomic magnetometers.

[0003] Semiconductor lasers, with their advantages of small size, narrow linewidth, high power, and tunability, are considered ideal light sources for quantum precision measurement, especially in cold atom detection. Cold atom detection technology relies on laser cooling, trapping, and detection, placing stringent requirements on the laser frequency. While traditional saturated absorption frequency-stabilized laser systems have achieved high-precision frequency stability and repeatability, they are still limited to atomic energy levels and struggle to maintain high sensitivity under detuning conditions, often resulting in complex system designs. Therefore, improving frequency stability with minimal system complexity is a pressing issue that needs to be addressed. Summary of the Invention

[0004] In view of this, the present invention provides a tunable frequency stabilization method, system and apparatus for semiconductor lasers to solve the problem of low frequency stability.

[0005] In a first aspect, the present invention provides a tunable frequency stabilization method for a semiconductor laser, applied to a semiconductor laser system, the semiconductor laser system including a seed source polarization beam splitter, the method comprising:

[0006] In response to the start command, the seed source control of the semiconductor laser is activated;

[0007] Adjust the temperature of the seed source electronic control to a first temperature, and adjust the current of the seed source electronic control to a first current;

[0008] In response to the adjustment operation of the seed source polarization beam splitter, the photocurrent is controlled to be in the step range of the nonlinear region of the photodiode;

[0009] Frequency sweep modulation is applied to the seed source electronic control to extract the differential signal of the photodetector, and frequency stabilization is performed based on the differential signal.

[0010] In one alternative implementation, after activating the seed source electrical control of the semiconductor laser, the method further includes:

[0011] The current is controlled to make the optical power reach a preset power range, wherein the preset power range characterizes the optical power range corresponding to the atomic magnetometer.

[0012] In one optional implementation, adjusting the temperature of the seed source to a first preset temperature includes:

[0013] Adjust the temperature of the seed source and monitor the lasing wavelength in real time;

[0014] When the temperature of the seed source is a first temperature, the lasing wavelength is within the preset wavelength range corresponding to the operating point of the magnetometer.

[0015] In one optional implementation, adjusting the current of the seed source control to a first preset current includes:

[0016] Adjust the current of the seed source electronic control and monitor the lasing wavelength in real time;

[0017] When the current of the seed source is a first current, the lasing wavelength is the first wavelength corresponding to the operating point of the magnetometer.

[0018] In one optional implementation, controlling the photocurrent within the step range of the photodiode's nonlinear region in response to the adjustment operation of the seed source polarization beam splitter includes:

[0019] In response to the adjustment operation of the seed source polarizing beam splitter, the light power incident on the photodiode is adjusted;

[0020] The photocurrent is monitored in real time until it falls within the step range of the nonlinear region of the photodiode.

[0021] In one optional implementation, applying sweep frequency modulation to the seed source electronic control to extract the differential signal from the photodetector includes:

[0022] A sweep signal is applied to the seed source electronic control based on the frequency stabilization program, and a sine modulation differential processing is added to the output signal of the photodetector to obtain the differential signal of the photodetector.

[0023] In one optional implementation, the frequency stabilization based on the differential signal includes:

[0024] The voltage corresponding to the midpoint of the differential signal is extracted as the reference voltage;

[0025] Obtain real-time voltage;

[0026] When the real-time voltage deviates from the reference voltage, a correction voltage is fed back to the seed source control, and frequency stabilization is performed based on the control signal.

[0027] This embodiment provides a tunable frequency stabilization method for semiconductor lasers, including: activating the seed source control of the semiconductor laser in response to a start command; adjusting the temperature of the seed source control to a first temperature and adjusting the current of the seed source control to a first current; controlling the photocurrent to be in the step range of the nonlinear region of the photodiode in response to the adjustment operation of the seed source polarization beam splitter; applying sweep frequency modulation to the seed source control, extracting the differential signal of the photodetector, and stabilizing the frequency based on the differential signal. This method adjusts the optical power received by the photodiode in the optical path system, causing the photodiode to reach the step range of the nonlinear region, and uses its output differential signal to stabilize the frequency of the laser amplified signal. It eliminates the Doppler broadening effect of saturated absorption frequency stabilization under detuning conditions, improves the frequency stability of the optical path system at specific application wavelengths, reduces the complexity of the frequency-stabilized laser system, and expands its application scenarios due to its tunable frequency stabilization wavelength.

[0028] In a second aspect, the present invention provides a semiconductor laser system, comprising:

[0029] Seed laser, seed source isolator, seed source waveplate, seed source polarizing beam splitter, side beam splitter, wavelength detection collimator, photodiode, main path first collimator, main path second collimator, first aspherical lens, cone amplifier laser, second aspherical lens, cone amplifier isolator, cone amplifier waveplate, power output collimator, power detector, wavelength meter, photodetector amplifier, and oscilloscope;

[0030] The laser beam is emitted from the seed laser and sequentially reaches the seed source isolator, the seed source waveplate and the seed source polarization beam splitter. The main beam and the probe beam are reflected out by the seed source polarization beam splitter.

[0031] The probe beam reaches the side beam splitter and is reflected by the side beam splitter to the photodiode detector and the wavelength detection collimator. The photodiode detector is connected to the photodetector amplifier by optical fiber, the wavelength detection collimator is connected to the wavelength meter by optical fiber, and the photodetector amplifier is connected to the oscilloscope by optical fiber.

[0032] The main beam reaches the first collimator of the main path. The first collimator of the main path is connected to the second collimator of the main path by optical fiber. The main beam is emitted through the first collimator of the main path and the second collimator of the main path, and arrives in sequence at the first aspherical lens, the cone amplifier laser, the second aspherical lens, the cone amplifier isolator, the cone amplifier waveplate, the power output collimator and the power detector. The power output collimator and the power detector are connected by optical fiber.

[0033] Thirdly, the present invention provides a tunable frequency stabilization device for a semiconductor laser, comprising:

[0034] An electronically controlled start-up module is used to activate the seed source electronic control of the semiconductor laser in response to a start-up command.

[0035] An adjustment module is used to adjust the temperature of the seed source to a first temperature and adjust the current of the seed source electronic control to a first current;

[0036] The prism adjustment module is used to control the photocurrent to be in the step range of the nonlinear region of the photodiode in response to the adjustment operation of the seed source polarization beam splitter.

[0037] The frequency stabilization module is used to apply sweep frequency modulation to the seed source electronic control, extract the differential signal of the photodetector, and stabilize the frequency based on the differential signal. Attached Figure Description

[0038] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0039] Figure 1 This is a schematic diagram of a semiconductor laser system according to an embodiment of the present invention;

[0040] Figure 2 This is a schematic flowchart of a tunable frequency stabilization method for a semiconductor laser according to an embodiment of the present invention;

[0041] Figure 3 This is a graph of a tunable frequency stabilization method for a semiconductor laser according to an embodiment of the present invention;

[0042] Figure 4 This is a structural block diagram of a tunable frequency stabilization device for a semiconductor laser according to an embodiment of the present invention;

[0043] Figure 5 This is a schematic diagram of the hardware structure of an electronic device according to an embodiment of the present invention.

[0044] Figure label:

[0045] Seed laser 1, seed source isolator 2, seed source waveplate 3, seed source polarizing beam splitter 4, side beam splitter 5, wavelength detection collimator 6, photodiode detector 7, main path first collimator 8, main path second collimator 9, first aspherical lens 10, cone amplifier laser 11, second aspherical lens 12, cone amplifier isolator 13, cone amplifier waveplate 14, power output collimator 15, power detector 16, wavelength meter 17, photodetector amplifier 18, oscilloscope 19. Detailed Implementation

[0046] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0047] This embodiment provides a semiconductor laser system, such as Figure 1 As shown, it includes: a seed laser 1, a seed source isolator 2, a seed source waveplate 3, a seed source polarizing beam splitter 4, a side beam splitter 5, a wavelength detection collimator 6, a photodiode detector 7, a main path first collimator 8, a main path second collimator 9, a first aspherical lens 10, a cone amplifier laser 11, a second aspherical lens 12, a cone amplifier isolator 13, a cone amplifier waveplate 14, a power output collimator 15, a power detector 16, a wavelength meter 17, a photodetector amplifier 18, and an oscilloscope 19.

[0048] The laser beam is emitted from the seed laser and sequentially reaches the seed source isolator 2, the seed source waveplate 3 and the seed source polarization beam splitter 4. The main beam and the probe beam are reflected by the seed source polarization beam splitter 4.

[0049] The probe beam reaches the side beam splitter 5 and is reflected by the side beam splitter 5 to the photodiode detector 7 and the wavelength detection collimator 6. The photodiode detector 7 is connected to the photodetector amplifier 18 by optical fiber, the wavelength detection collimator 6 is connected to the wavelength meter 17 by optical fiber, and the photodetector amplifier 18 is connected to the oscilloscope 19 by optical fiber.

[0050] The main beam reaches the first collimator 8, which is connected to the second collimator 9 by optical fiber. The main beam is emitted through the first collimator 8 and the second collimator 9 and arrives sequentially at the first aspherical lens 10, the cone amplifier laser 11, the second aspherical lens 12, the cone amplifier isolator 13, the cone amplifier waveplate 14, the power output collimator 15, and the power detector 16. The power output collimator 15 and the power detector 16 are connected by optical fiber.

[0051] The probe beam reflected by the seed source polarizing beam splitter 4 reaches the photodiode detector 7 via the side beam splitter 5. Therefore, the magnitude of the probe beam can be adjusted by changing the waveplate angle of the seed source polarizing beam splitter 4, thereby changing the optical power received at the photodiode detector and controlling the photocurrent to be within the step range of the photodiode's nonlinear region. Another path of the probe beam reflected by the seed source polarizing beam splitter 4 reaches the wavelength detection collimator 6, which is connected to the wavelength meter 17, allowing the wavelength to be monitored. The seed laser 1 is a DFB seed laser (Distributed Feedback Laser), the seed source waveplate 3 is a seed source half-waveplate, and the tapered amplifier waveplate 14 is a tapered amplifier half-waveplate.

[0052] In some alternative implementations, the semiconductor laser system is a TA (Tapered Amplifier) ​​laser system, which is connected to a distributed feedback (DFB) laser seed source control and a tapered amplifier (TA) laser control, respectively. The DFB laser seed source control is used to regulate the wavelength of the emitted light, and the tapered amplifier laser control is used to adjust the output power of the optical amplifier.

[0053] In some optional implementations, the seed laser 1 is a DFB semiconductor laser with a center wavelength of 794.98 nm, an output power of 80 mW, and a linewidth of 0.6 MHz, tuned by a temperature controller (accuracy ±0.01 °C) and a current controller (accuracy 0.1 mA); the photodiode detector 7 is a Thorlabs SM05PD2A model with a step range of 71.00~73.00 μA; the TA amplifier amplifies the wavelength range of 760~810 nm; and the wavelength meter is a High Finesse WS8 with a measurement accuracy down to 10 nm. -7 nm; the photodetector amplifier selected is Thorlabs PDA200C, with a magnification of 100 times.

[0054] In terms of the optical path, the laser beam is split into two beams after passing through the seed source polarization beam splitter. The power ratio of the pump light (main path) and the probe light (measurement path) is approximately 9:1. The probe light is reflected by the side beam splitter and received by the photodiode detector. Error signal generation: A 4Hz sawtooth wave sweep signal with a sweep voltage of ±2.0V is applied to the DFB seed source. A 100kHz sinusoidal modulation signal with a modulation voltage of 50mV is then applied to demodulate the output of the photodiode amplifier, extracting the first harmonic as the error signal. Its zero-crossing point corresponds to the peak gain in the nonlinear region of the photodiode. For feedback control, the midpoint voltage value of the error signal is input into the frequency stabilization program, and the output is fed back to the seed source laser's control terminal to achieve frequency stabilization. The PID (Proportional-Integral-Differential) parameters are optimized to achieve a frequency stability of 10% over 16 hours. -10 level.

[0055] According to an embodiment of the present invention, a method for tunable frequency stabilization of a semiconductor laser is provided. It should be noted that the steps shown in the flowchart in the accompanying drawings can be executed in a computer system such as a set of computer-executable instructions. Furthermore, although a logical order is shown in the flowchart, in some cases, the steps shown or described may be executed in a different order than that shown here.

[0056] This embodiment provides a tunable frequency stabilization method for a semiconductor laser, which can be used in the aforementioned semiconductor laser system. The semiconductor laser system includes a seed source polarization beam splitter. Figure 2 This is a flowchart of a tunable frequency stabilization method for a semiconductor laser according to an embodiment of the present invention, such as... Figure 2 As shown, the process includes the following steps:

[0057] Step S101: In response to the start command, the seed source control of the semiconductor laser is activated.

[0058] Before turning on the seed source control of the semiconductor laser, first turn on the atomic magnetometer and its light source semiconductor TA laser (Tapered Amplifier Laser). The main path of the laser is connected to the magnetometer via optical fiber.

[0059] The start command can be manually entered through the operating interface, or it can be automatically generated based on preset conditions of the semiconductor laser system. For a semiconductor laser to function properly, precise electrical control of its seed source is required. The seed source is the foundation for laser generation in a semiconductor laser. The electrical control system provides suitable power conditions to the seed source to excite it to generate light signals with specific frequencies and characteristics. Specifically, the seed source electrical control employs a distributed feedback laser seed source control system.

[0060] Step S102: Adjust the temperature of the seed source control to the first temperature and adjust the current of the seed source control to the first current.

[0061] Temperature has a significant impact on the performance of semiconductor lasers; different temperatures can cause changes in parameters such as the output wavelength and power of the laser.

[0062] The wavelength tuning factor for the seed source control's temperature adjustment is greater than its current tuning factor. Therefore, the seed source control's temperature is first adjusted to a first temperature, and then the current is adjusted to a first current. The lasing wavelength is observed while adjusting the temperature and current. A wavelength meter is connected to the side circuit of the semiconductor laser system to monitor the lasing wavelength. First, adjust the temperature of the seed source electronic control to the first temperature so that the lasing wavelength reaches near the working point of the magnetometer. Then, fine-tune the current to the first current, at which point the wavelength is at the working point of the magnetometer.

[0063] Step S103: In response to the adjustment operation of the seed source polarization beam splitter, the photocurrent is controlled to be in the step range of the nonlinear region of the photodiode.

[0064] Adjusting the waveplate of the seed source polarizing beam splitter adjusts the optical power received by the photodiode detector. The photocurrent reading converted by the photodiode can be read on the photodiode amplifier until the photocurrent is in the step range of the photodiode's nonlinear region.

[0065] A photodiode is a device that converts optical signals into electrical signals. There is a linear relationship between its output current and input optical power under normal circumstances. However, in certain situations, when the optical power reaches a certain range, the photodiode enters a nonlinear region. At this point, the relationship between the output current and the optical power is no longer a simple linear one, but rather exhibits nonlinear characteristics such as step changes.

[0066] Step S104: Apply sweep frequency modulation to the seed source electronic control, extract the differential signal of the photodetector, and stabilize the frequency based on the differential signal.

[0067] Frequency sweep modulation refers to making the frequency of the signal output by the seed source electronic control continuously change within a certain range according to a certain rule. By applying frequency sweep modulation, the output frequency of the laser can be changed, thereby enabling comprehensive detection and adjustment of the laser's frequency characteristics.

[0068] When the photocurrent is within the step range of the photodiode's nonlinear region, a sweep frequency signal is applied for modulation. During the sweep frequency modulation process, the electrical signal output by the photodetector contains information about the laser's frequency changes. Through specific signal processing circuits and algorithms, a differential signal can be extracted from the electrical signal output by the photodetector. The differential signal is the result of differentiating the output electrical signal.

[0069] Based on the deviation between the target frequency at the midpoint of the differential signal and the current output frequency of the laser, the control system will adjust the current of the seed source control to reduce the deviation between the output and the set frequency, so that the output frequency of the laser gradually approaches and stabilizes at the target frequency.

[0070] This embodiment provides a tunable frequency stabilization method for semiconductor lasers, including: activating the seed source control of the semiconductor laser in response to a start command; adjusting the temperature of the seed source control to a first temperature and adjusting the current of the seed source control to a first current; controlling the photocurrent to be within the step range of the photodiode's nonlinear region in response to an adjustment operation of the seed source polarization beam splitter; applying sweep frequency modulation to the seed source control, extracting the differential signal of the photodetector, and stabilizing the frequency based on the differential signal. This method adjusts the optical power received by the photodiode in the optical path system, causing the photodiode to reach the step range of the nonlinear region, and uses its output differential signal to stabilize the frequency of the laser amplified signal. It eliminates the Doppler broadening effect of saturated absorption frequency stabilization under detuning conditions, improves the frequency stability of the optical path system at specific application operating wavelengths, reduces the complexity of the frequency-stabilized laser system, and expands its application scenarios due to its tunable frequency stabilization wavelength.

[0071] This embodiment provides a tunable frequency stabilization method for a semiconductor laser, which can be used in the aforementioned semiconductor laser system. The semiconductor laser system includes a seed source polarization beam splitter. The method includes the following steps:

[0072] Step S201: In response to the start command, the seed source control of the semiconductor laser is activated.

[0073] Please see details Figure 2 Step S101 of the illustrated embodiment will not be described again here.

[0074] In some alternative implementations, after activating the seed source electrical control of the semiconductor laser, the method further includes: controlling the current to bring the optical power to a preset power range, wherein the preset power range characterizes the optical power range corresponding to the atomic magnetometer.

[0075] The current is applied to the vicinity of the laser power required by the atomic magnetometer, i.e., the preset power range.

[0076] Step S202: Adjust the temperature of the seed source electronic control to the first temperature and adjust the current of the seed source electronic control to the first current.

[0077] Step S202 above includes:

[0078] Step S2021: Adjust the temperature of the seed source and monitor the lasing wavelength in real time;

[0079] Step S2022: When the temperature of the seed source is the first temperature, the lasing wavelength is within the preset wavelength range corresponding to the working point of the magnetometer.

[0080] Step S2023: Adjust the current of the seed source electronic control and monitor the lasing wavelength in real time;

[0081] Step S2024, when the current of the seed source is the first current.

[0082] The lasing wavelength is the first wavelength corresponding to the magnetometer's operating point. The lasing wavelength is monitored while adjusting the temperature of the seed source control. When the lasing wavelength falls within the preset wavelength range corresponding to the magnetometer's operating point, the temperature of the seed source control is the first temperature. The lasing wavelength is monitored while adjusting the current of the seed source control. When the lasing wavelength falls within the wavelength corresponding to the magnetometer's operating point, the current of the seed source control is the first current. The wavelength corresponding to the magnetometer's operating point is λ0 = 795.018 nm.

[0083] Step S203: In response to the adjustment operation of the seed source polarization beam splitter, the photocurrent is controlled to be in the step range of the nonlinear region of the photodiode.

[0084] Specifically, step S203 includes: adjusting the light power incident on the photodiode in response to the adjustment operation of the seed source polarizing beam splitter; and monitoring the photocurrent in real time until the photocurrent is in the step range of the nonlinear region of the photodiode.

[0085] When the laser output wavelength is the wavelength corresponding to the working point of the magnetometer (i.e., λ0=795.018nm), the waveplate of the seed source polarization beam splitter is rotated to change the light power received at the photodiode, and the photocurrent reading converted by the photodiode is read through the photodetector amplifier.

[0086] Step S204: Apply sweep frequency modulation to the seed source electronic control, extract the differential signal of the photodetector, and stabilize the frequency based on the differential signal.

[0087] Specifically, step S204 includes:

[0088] Step S2041: Apply a sweep signal to the seed source electronic control based on the frequency stabilization program, and add a sine modulation differential processing to the output signal of the photodetector to obtain the differential signal of the photodetector.

[0089] Step S2042: Extract the voltage corresponding to the midpoint of the differential signal as the reference voltage;

[0090] Step S2043: Obtain the real-time voltage;

[0091] Step S2044: When the real-time voltage deviates from the reference voltage, a correction voltage is fed back to the seed source control, and frequency stabilization is performed based on the control signal.

[0092] When the photocurrent reading I converted by the photodiode is read PD , when I PD Step interval I in the nonlinear region of a photodiode PD1 ~I PD2 During this period, a sweep signal U is applied to the seed source electronic control via a frequency stabilization program. sweep (-2.0V≤U) sweep (≤2.0V), and simultaneously, the differential signal processed by differentiation is displayed on the oscilloscope. This differential signal is a steep upward curve, representing the drastic change in the photodiode's gain within this range. The zero point of the differential signal corresponds to the peak value of the photodiode's gain. The dip at the peak value can be used for frequency locking of the laser; the frequency locking principle is similar to saturated absorption frequency stabilization. The midpoint of the differential signal curve at the steep point can be approximated as its zero point.

[0093] The voltage corresponding to the midpoint of the differential signal is the voltage value corresponding to the midpoint of the curve. This voltage value is used as the reference voltage, i.e., the frequency lock reference. When the frequency stabilization program reads that the differential signal voltage is far from the reference voltage, it will apply a small voltage ΔU to the distributed feedback laser control to pull its excitation frequency back to the frequency corresponding to the reference voltage, thus achieving frequency stabilization.

[0094] Frequency stabilization is achieved by issuing control signals through preset PID (Proportional-Integral-Differential) control parameters.

[0095] If it is necessary to tune to other wavelength operating points, the lasing wavelength can be adjusted to any wavelength point within the tuning range of the distributed feedback laser for frequency stabilization.

[0096] In some alternative implementations, the step interval I of the nonlinear region of the photodiode PD1 ~I PD2 When using the Thorlabs SM05PD2A photodiode, the corresponding value is 71.00. ~73.00 .

[0097] The tunable frequency stabilization method for semiconductor lasers provided in this embodiment ensures the stability of the light source used in a magnetometer system, specifically including its narrow linewidth characteristics, power stability, and frequency stability. The frequency stability of the cone amplifier laser during normal operation for eight hours is 10. -6 Level. This invention leverages the step gain characteristic of photodiodes in the nonlinear region to lock the frequency of a cone amplifier laser at the wavelength point corresponding to the midpoint of the step interval. This wavelength point can be freely tuned by temperature and current, achieving frequency stability of the cone amplifier laser at the magnetometer's operating point, with a frequency stability of less than 10%. -10This further enhances the measurement sensitivity of the atomic magnetometer. By adjusting the optical power received by the photodiode to reach the step range of the photodiode's nonlinear region, this invention enables frequency locking of any wavelength within the tuning range of the DFB seed laser source, providing a vast wavelength tuning space and flexible application in various scenarios, such as cold atom detection, quantum computing, biomedical imaging, and optical communication. Simultaneously, the frequency-stabilized cone amplifier laser using this method exhibits excellent frequency stabilization time (>16H) and frequency stability (<10H). -10 Both are higher than the frequency stabilization effect of saturated absorption under detuning. Figure 3 The optical power of the input photodiode and the generated photocurrent I PD The PI curve, photodiode gain, and differential signal and sawtooth wave signal of the photodiode after differentiation processing on the oscilloscope.

[0098] This embodiment also provides a tunable frequency stabilization device for a semiconductor laser, which is used to implement the above embodiments and preferred embodiments; details already described will not be repeated. As used below, the term "module" can refer to a combination of software and / or hardware that performs a predetermined function. Although the device described in the following embodiments is preferably implemented in software, hardware implementation, or a combination of software and hardware, is also possible and contemplated.

[0099] This embodiment provides a tunable frequency stabilization device for a semiconductor laser, such as... Figure 4 As shown, it includes:

[0100] An electronically controlled start-up module is used to activate the seed source electronic control of the semiconductor laser in response to a start-up command.

[0101] An adjustment module is used to adjust the temperature of the seed source to a first temperature and adjust the current of the seed source electronic control to a first current;

[0102] The prism adjustment module is used to control the photocurrent to be in the step range of the nonlinear region of the photodiode in response to the adjustment operation of the seed source polarization beam splitter.

[0103] The frequency stabilization module is used to apply sweep frequency modulation to the seed source electronic control, extract the differential signal of the photodetector, and stabilize the frequency based on the differential signal.

[0104] Further functional descriptions of the above modules and units are the same as those in the corresponding embodiments described above, and will not be repeated here.

[0105] In this embodiment, the tunable frequency stabilization device for semiconductor lasers is presented in the form of a functional unit. Here, a unit refers to an ASIC (Application Specific Integrated Circuit) circuit, a processor and memory that execute one or more software or fixed programs, and / or other devices that can provide the above functions.

[0106] This invention also provides an electronic device having the above-described tunable frequency stabilization device for a semiconductor laser.

[0107] Please see Figure 5 , Figure 5 This is a schematic diagram of the structure of an electronic device provided in an optional embodiment of the present invention, such as... Figure 5 As shown, the electronic device includes one or more processors 40, memory 20, and interfaces for connecting the components, including high-speed interfaces and low-speed interfaces. The components communicate with each other via different buses and can be mounted on a common motherboard or otherwise as required. The processors can process instructions executed within the electronic device, including instructions stored in or on memory to display graphical information of a GUI on external input / output devices (such as display devices coupled to the interfaces). In some alternative implementations, multiple processors and / or multiple buses can be used with multiple memories and multiple memory modules, if desired. Similarly, multiple electronic devices can be connected, each providing some of the necessary operations (e.g., as a server array, a group of blade servers, or a multiprocessor system). Figure 5 Take a processor 40 as an example.

[0108] Processor 40 may be a central processing unit, a network processor, or a combination thereof. Processor 40 may further include a hardware chip. The hardware chip may be an application-specific integrated circuit (ASIC), a programmable logic device (PLD), or a combination thereof. The programmable logic device may be a complex programmable logic device (CAMP), a field-programmable gate array (FPGA), a general-purpose array logic (GBA), or any combination thereof.

[0109] The memory 20 stores instructions executable by at least one processor 40 to cause the at least one processor 40 to perform the method shown in the above embodiments.

[0110] The memory 20 may include a program storage area and a data storage area. The program storage area may store the operating system and applications required for at least one function; the data storage area may store data created based on the use of the electronic device. Furthermore, the memory 20 may include high-speed random access memory and may also include non-transitory memory, such as at least one disk storage device, flash memory device, or other non-transitory solid-state storage device. In some alternative embodiments, the memory 20 may optionally include memory remotely located relative to the processor 40, and these remote memories may be connected to the electronic device via a network. Examples of such networks include, but are not limited to, the Internet, intranets, local area networks, mobile communication networks, and combinations thereof.

[0111] The memory 20 may include volatile memory, such as random access memory; the memory may also include non-volatile memory, such as flash memory, hard disk or solid-state drive; the memory 20 may also include a combination of the above types of memory.

[0112] The electronic device also includes a communication interface 30 for communicating with other devices or communication networks.

[0113] This invention also provides a computer-readable storage medium. The methods described above according to embodiments of the invention can be implemented in hardware or firmware, or implemented as computer code that can be recorded on a storage medium, or implemented as computer code downloaded via a network and originally stored on a remote storage medium or a non-transitory machine-readable storage medium and then stored on a local storage medium. Thus, the methods described herein can be processed by software stored on a storage medium using a general-purpose computer, a dedicated processor, or programmable or dedicated hardware. The storage medium can be a magnetic disk, optical disk, read-only memory, random access memory, flash memory, hard disk, or solid-state drive, etc.; further, the storage medium can also include combinations of the above types of memory. It is understood that computers, processors, microprocessor controllers, or programmable hardware include storage components capable of storing or receiving software or computer code, which, when accessed and executed by the computer, processor, or hardware, implements the methods shown in the above embodiments.

[0114] A portion of this invention can be applied as a computer program product, such as computer program instructions, which, when executed by a computer, can invoke or provide the methods and / or technical solutions according to the invention through the operation of the computer. Those skilled in the art will understand that the forms in which computer program instructions exist in a computer-readable medium include, but are not limited to, source files, executable files, installation package files, etc. Correspondingly, the ways in which computer program instructions are executed by a computer include, but are not limited to: the computer directly executing the instructions, or the computer compiling the instructions and then executing the corresponding compiled program, or the computer reading and executing the instructions, or the computer reading and installing the instructions and then executing the corresponding installed program. Here, the computer-readable medium can be any available computer-readable storage medium or communication medium accessible to a computer.

[0115] Although embodiments of the invention have been described in conjunction with the accompanying drawings, those skilled in the art can make various modifications and variations without departing from the spirit and scope of the invention, and all such modifications and variations fall within the scope defined by the invention.

Claims

1. A semiconductor laser system, characterized in that, include: Seed laser, seed source isolator, seed source waveplate, seed source polarizing beam splitter, side beam splitter, wavelength detection collimator, photodiode detector, main path first collimator, main path second collimator, first aspherical lens, cone amplifier laser, second aspherical lens, cone amplifier isolator, cone amplifier waveplate, power output collimator, power detector, wavelength meter, photodetector amplifier, and oscilloscope; The laser beam is emitted from the seed laser and sequentially reaches the seed source isolator, the seed source waveplate and the seed source polarization beam splitter, and the main beam and the probe beam are reflected by the seed source polarization beam splitter. The detection beam reaches the side beam splitter and is reflected by the side beam splitter to the photodiode detector and the wavelength detection collimator. The photodiode detector and the photodetector amplifier are connected by optical fiber. The wavelength detection collimator and the wavelength meter are connected by optical fiber. The photodetector amplifier and the oscilloscope are connected by optical fiber. The main beam reaches the first collimator of the main path, and the first collimator of the main path is optically connected to the second collimator of the main path. The main beam is emitted through the first collimator of the main path and the second collimator of the main path, and sequentially reaches the first aspherical lens, the cone amplifier laser, the second aspherical lens, the cone amplifier isolator, the cone amplifier waveplate, the power output collimator and the power detector. The power output collimator and the power detector are optically connected.

2. The semiconductor laser system according to claim 1, characterized in that, The semiconductor laser system is connected to a distributed feedback laser seed source control and a cone amplifier laser control, respectively. The distributed feedback laser seed source control is used to regulate the wavelength of the emitted light, and the cone amplifier laser control is used to adjust the output power of the optical amplifier.

3. A tunable frequency stabilization method for a semiconductor laser, characterized in that, Applied to the semiconductor laser system according to any one of claims 1-2, the semiconductor laser system comprising a seed source polarizing beam splitter, the method comprises: In response to the start command, the seed source control of the semiconductor laser is activated; Adjust the temperature of the seed source electronic control to a first temperature, and adjust the current of the seed source electronic control to a first current; In response to the adjustment operation of the seed source polarization beam splitter, the photocurrent is controlled to be in the step range of the nonlinear region of the photodiode; Frequency sweep modulation is applied to the seed source electronic control to extract the differential signal of the photodetector, and frequency stabilization is performed based on the differential signal.

4. The method according to claim 3, characterized in that, After the seed source electrical control of the semiconductor laser is activated, the method further includes: The current is controlled to make the optical power reach a preset power range, wherein the preset power range characterizes the optical power range corresponding to the atomic magnetometer.

5. The method according to claim 3, characterized in that, Adjusting the temperature of the seed source to a first preset temperature includes: Adjust the temperature of the seed source and monitor the lasing wavelength in real time; When the temperature of the seed source is a first temperature, the lasing wavelength is within the preset wavelength range corresponding to the operating point of the magnetometer.

6. The method according to claim 5, characterized in that, Adjusting the current of the seed source control to a first preset current includes: Adjust the current of the seed source electronic control and monitor the lasing wavelength in real time; When the current of the seed source is a first current, the lasing wavelength is the first wavelength corresponding to the operating point of the magnetometer.

7. The method according to claim 3, characterized in that, The step of controlling the photocurrent within the step range of the photodiode's nonlinear region in response to the adjustment operation of the seed source polarization beam splitter includes: In response to the adjustment operation of the seed source polarizing beam splitter, the light power incident on the photodiode is adjusted; The photocurrent is monitored in real time until it falls within the step range of the nonlinear region of the photodiode.

8. The method according to claim 3, characterized in that, The step of applying sweep frequency modulation to the seed source electronic control and extracting the differential signal from the photodetector includes: A sweep signal is applied to the seed source electronic control based on the frequency stabilization program, and a sine modulation differential processing is added to the output signal of the photodetector to obtain the differential signal of the photodetector.

9. The method according to claim 8, characterized in that, The frequency stabilization based on the differential signal includes: The voltage corresponding to the midpoint of the differential signal is extracted as the reference voltage; Obtain real-time voltage; When the real-time voltage deviates from the reference voltage, a correction voltage is fed back to the seed source control, and frequency stabilization is performed based on the control signal.

10. A tunable frequency stabilization device for a semiconductor laser, characterized in that, Applied to the semiconductor laser system according to any one of claims 1-2, comprising: An electronically controlled start-up module is used to activate the seed source electronic control of the semiconductor laser in response to a start-up command. An adjustment module is used to adjust the temperature of the seed source to a first temperature and adjust the current of the seed source's electronic control to a first current. The prism adjustment module is used to control the photocurrent within the step range of the nonlinear region of the photodiode in response to the adjustment operation of the seed source polarization beam splitter. The frequency stabilization module is used to apply sweep frequency modulation to the seed source electronic control, extract the differential signal of the photodetector, and stabilize the frequency based on the differential signal.

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