Apparatus and method for adjusting the output frequency of a laser based on atomic transitions

Abstract

The application discloses a kind of device and method based on atomic transition adjustment laser output frequency, comprising: laser, for outputting to be stabilized frequency shift laser;Modulation module, for receiving the stabilized frequency shift laser output by laser, and after using radio frequency signal to modulate the frequency of stabilized frequency shift laser, output single sideband modulation laser;Frequency stabilization module, for receiving single sideband modulation laser and generating frequency discrimination signal, frequency stabilization module is electrically connected with laser, and frequency discrimination signal is fed back to laser, to adjust the frequency of laser output laser, so that single sideband modulation laser is locked on selected atomic transition spectrum line.The application combines the modulation module and frequency stabilization module of laser, and acoustooptic modulator and fiber electro-optic modulator in modulation module are sequentially connected, so that wide-range high-precision adjustment of laser frequency can be realized.The application has the characteristics of simple device, strong robustness and wide applicability, so that it can be widely applied in different fields.

Description

Technical Field

[0001] This invention relates to the field of laser technology, and specifically to a device and method for adjusting the output frequency of a laser based on atomic transitions. Background Technology

[0002] Lasers have wide applications in cold atom physics, quantum optics, quantum precision measurement and sensing. In scenarios involving the precise manipulation of atoms and related precision measurements using lasers, it is often necessary to precisely adjust the laser frequency over a wide range.

[0003] To ensure high frequency stability of laser output, laser frequency stabilization techniques are typically used to lock the laser frequency to a specific reference source, such as atomic transition lines or ultrastable cavities. However, precisely adjusting the locked laser frequency over a wide range is challenging. A common method for achieving this is frequency shifting using acousto-optic modulators (ACIMs). However, ACIMs typically operate at frequencies in the hundreds of MHz range, resulting in a relatively small frequency adjustment range. Furthermore, the frequency shifting efficiency of ACIMs decreases as the driving frequency increases. Electro-optic modulators can also be used to modulate the laser and generate sidebands, but these sidebands spatially overlap with the carrier wave, and the laser power in the sidebands is generally low. Summary of the Invention

[0004] In order to overcome the shortcomings of the prior art, the present invention aims to provide a device and method for adjusting the output frequency of a laser based on atomic transitions, which solves the problems of relatively small frequency adjustment range and spatial overlap of sidebands and carrier in the prior art, thereby achieving the purpose of precise adjustment of laser frequency over a large range.

[0005] To solve the above problems, the technical solution adopted by the present invention is as follows:

[0006] A device for adjusting the output frequency of a laser based on atomic transitions, comprising:

[0007] A laser used to output a frequency-shifting laser signal that needs to be stabilized;

[0008] The modulation module is used to receive the frequency-shifted laser to be stabilized output by the laser, and modulate the frequency of the frequency-shifted laser to be stabilized using radio frequency signals, and output a single-sideband modulated laser.

[0009] A frequency stabilization module is used to receive the single-sideband modulated laser and generate a frequency discrimination signal. The frequency stabilization module is electrically connected to the laser and feeds back the frequency discrimination signal to the laser to adjust the frequency of the laser output by the laser, so that the single-sideband modulated laser is locked on the selected atomic transition spectral line.

[0010] In a preferred embodiment of the present invention, the modulation module includes:

[0011] The input unit is used to adjust the polarization direction of the frequency-shifting laser output by the laser to be stabilized and to split the beam.

[0012] The frequency shifting unit is used to receive the split beam input from the input unit, and to shift and modulate the split beam to output laser light with a specific sideband frequency;

[0013] A microwave frequency source is used to drive the frequency shifting unit.

[0014] In a preferred embodiment of the present invention, the input unit includes:

[0015] The first half-wave plate is used to adjust the polarization direction of the frequency-shifting laser to be stabilized;

[0016] The first polarization beam splitter is used to split the frequency-shifting laser beam to be stabilized after being adjusted by the first half-wave plate.

[0017] In a preferred embodiment of the present invention, the frequency shifting unit includes:

[0018] An acousto-optic modulator is used to receive the laser beam split from the first polarization beam splitter and perform a first frequency shift. The acousto-optic modulator is electrically connected to the microwave frequency source and is driven by the microwave frequency source.

[0019] The first reflecting mirror is used to reflect the laser, which has undergone the first frequency shift, back to the acousto-optic modulator for a second frequency shift;

[0020] A fiber electro-optic modulator is used to receive beam split light that has undergone a second frequency shift, modulate it, and output a single-sideband modulated laser. The fiber electro-optic modulator is electrically connected to the microwave frequency source and is driven by the microwave frequency source.

[0021] In a preferred embodiment of the present invention, the frequency stabilization module includes:

[0022] The first frequency stabilization unit is used to receive the single-sideband modulated laser output from the fiber electro-optic modulator and generate a modulation transfer spectrum.

[0023] The second frequency stabilization unit is used to receive the modulation transfer spectrum output by the first frequency stabilization unit and generate a modulation frequency discrimination signal.

[0024] In a preferred embodiment of the present invention, the first frequency stabilization unit includes:

[0025] The second half-wave plate is used to adjust the polarization direction of the single-sideband modulated laser.

[0026] The second polarization beam splitter is used to receive the single-sideband modulated laser light adjusted by the second half-wave plate, and to cause the single-sideband modulated laser light to be reflected and transmitted to form probe light and pump light with orthogonal polarization states.

[0027] An atomic gas chamber, located in the optical path of the probe light, receives the normally incident probe light and absorbs it;

[0028] The reflecting device includes a second reflector and a third reflector, which reflect the pump light in sequence.

[0029] The third polarization beam splitter is used to reflect the pump light reflected by the third mirror into the atomic gas cell, where it recombines with the probe light to produce an absorption effect. The third polarization beam splitter can also allow the absorbed probe light to be transmitted.

[0030] In a preferred embodiment of the present invention, the second frequency stabilization unit includes:

[0031] A photodetector is used to receive the probe light transmitted through the third polarization beam splitter and convert it into an electrical signal;

[0032] A signal source, used to generate the modulated signal;

[0033] A frequency discriminator is used to receive the modulation signal output by the signal source and the electrical signal output by the photodetector, and output an error signal.

[0034] The PZT scanning module is used to scan the laser, determine the saturation absorption peak corresponding to an atomic transition, and output the saturation absorption peak value.

[0035] A PID controller is used to receive the error signal output by the frequency discriminator and output a control quantity.

[0036] A high-voltage amplifier is used to receive the saturated absorption peak, control quantity, and modulation signal, amplify them, and feed them back to the laser to lock the laser output frequency.

[0037] A method for adjusting the output frequency of a laser based on atomic transitions includes the following steps:

[0038] Use a laser to output a laser beam;

[0039] The polarization direction of the laser is adjusted using a half-wave plate, and the laser beam is split into a high-power laser and a low-power laser using a polarization beam splitter. The high-power laser is then directly output.

[0040] The low-power laser is subjected to double frequency shifting using an acousto-optic modulator, and then electro-optically modulated using a fiber electro-optic modulator to obtain a low-power laser with altered sideband frequencies.

[0041] The polarization direction of the low-power laser after the sideband frequency is changed is adjusted by using a half-wave plate, and then the polarization beam splitter is used for reflection and transmission to form probe light and pump light with orthogonal polarization states.

[0042] The pump light is reflected so that the probe light and the pump light act towards each other in the atomic gas cell;

[0043] The probe light is converted into an electrical signal using a photodetector, then converted into an error signal using a frequency discriminator, and finally output as a control signal. This control signal is then fed back to the laser in combination with the saturated absorption peak and the modulation signal, thereby locking the laser output frequency.

[0044] In a preferred embodiment of the present invention, when providing feedback to the laser, the following is included:

[0045] The PID controller receives the error signal output by the frequency discriminator and outputs a control quantity.

[0046] The laser was scanned using a PZT scanning module, and a saturation absorption peak was determined.

[0047] The error signal, control quantity, and saturation absorption peak value are fed back to the laser via a high-voltage amplifier.

[0048] In a preferred embodiment of the present invention, the adjustment method further includes: adjusting the driving frequency of the acousto-optic modulator and the fiber electro-optic modulator using a microwave frequency source to adjust the difference between the laser frequency output by the laser and the specified atomic transition frequency, wherein the output frequency of the laser is locked to the atomic transition line corresponding to the saturation absorption peak according to the set frequency difference.

[0049] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0050] This invention splits the laser output light into two parts. The lower-power portion is frequency-shifted using a combination of an acousto-optic modulator and a fiber electro-optic modulator. The frequency-shifted laser light is then input into a frequency stabilization module. The output signal of the frequency stabilization module provides feedback to the laser, locking the frequency-shifted laser light onto a selected atomic transition line. Changing the driving frequency of the acousto-optic modulator and the fiber electro-optic modulator is equivalent to changing the difference between the laser output light frequency and the atomic transition frequency, thus achieving precise adjustment of the laser output frequency. This invention features simple device, strong robustness, and wide applicability, and can be widely applied in fields such as cold atom physics, quantum optics, and quantum precision measurement and sensing.

[0051] The present invention will now be described in further detail with reference to the accompanying drawings and specific embodiments. Attached Figure Description

[0052] Figure 1 - This is a structural diagram of a device for adjusting the output frequency of a laser based on atomic transitions, according to an embodiment of the present invention;

[0053] Figure 2 - This is a flowchart of a method for adjusting the output frequency of a laser based on atomic transitions according to an embodiment of the present invention.

[0054] Explanation of reference numerals: 1. Laser; 2. First half-wave plate; 3. First polarization beam splitter; 4. Acousto-optic modulator; 5. Microwave frequency source; 6. First reflector; 7. Fiber electro-optic modulator; 8. Second half-wave plate; 9. Second polarization beam splitter; 10. Atomic gas cell; 11. Second reflector; 12. Third reflector; 13. Photodetector; 14. Signal source; 15. Frequency discriminator; 16. PZT scanning module; 17. PID controller; 18. High voltage amplifier. Detailed Implementation

[0055] The device for adjusting the output frequency of a laser based on atomic transitions provided by this invention, such as... Figure 1 As shown, the system includes: a laser 1, a modulation module, and a frequency stabilization module. Laser 1 outputs a frequency-shifted laser beam to be stabilized; the modulation module receives the frequency-shifted laser beam output from laser 1 and modulates its frequency using a radio frequency signal to output a single-sideband modulated laser beam; the frequency stabilization module receives the single-sideband modulated laser beam and generates a modulation transfer spectrum and a frequency discrimination signal. The frequency stabilization module is electrically connected to laser 1 and feeds back the frequency discrimination signal to laser 1 to adjust the frequency of the laser beam output from laser 1, thereby locking the single-sideband modulated laser beam onto a selected atomic transition line.

[0056] Preferably, the modulation module includes an input unit, a frequency shifting unit, and a microwave frequency source 5.

[0057] The input unit is used to adjust the polarization direction of the frequency-shifting laser output from laser 1 and to split the beam;

[0058] The frequency shifting unit is used to receive the split beam input from the input unit, and to shift and modulate the split beam to output laser light with a specific sideband frequency;

[0059] Microwave frequency source 5 is used to drive the frequency shifting unit.

[0060] More preferably, the input unit includes a first half-wave plate 2 and a first polarization beam splitter 3.

[0061] The first half-wave plate 2 is used to adjust the polarization direction of the frequency-shifting laser to be stabilized;

[0062] The first polarization beam splitter 3 is used to split the frequency-shifting laser beam to be stabilized after being adjusted by the first half-wave plate 2.

[0063] More preferably, the frequency shifting unit includes an acousto-optic modulator 4, a first reflector 6, and an optical fiber electro-optic modulator 7.

[0064] The acousto-optic modulator 4 is used to receive the laser beam split from the first polarization beam splitter 3 and perform the first frequency shift. The acousto-optic modulator 4 is electrically connected to the microwave frequency source 5 and is driven by the microwave frequency source 5.

[0065] The first reflector 6 is used to perform a second frequency shift on the laser reflection echo modulator 4, which has undergone the first frequency shift.

[0066] The fiber electro-optic modulator 7 is used to receive the split beam light after the second frequency shift and modulate it to output a single-sideband modulated laser. The fiber electro-optic modulator 7 is electrically connected to the microwave frequency source and is driven by the microwave frequency source 5.

[0067] Preferably, the frequency stabilization module includes a first frequency stabilization unit and a second frequency stabilization unit.

[0068] The first frequency stabilization unit is used to receive the single-sideband modulated laser output from the fiber electro-optic modulator 7 and generate a modulation transfer spectrum.

[0069] The second frequency stabilization unit is used to receive the modulation transfer spectrum output by the first frequency stabilization unit and generate a modulation frequency discrimination signal.

[0070] More preferably, the first frequency stabilizing unit includes a second half-wave plate 8, a second polarization beam splitter 9, an atomic gas cell 10, a reflecting device, and a third polarization beam splitter.

[0071] The second half-wave plate 8 is used to adjust the polarization direction of the single-sideband modulated laser;

[0072] The second polarization beam splitter 9 is used to receive the single-sideband modulated laser light adjusted by the second half-wave plate 8, and to make the single-sideband modulated laser light reflect and transmit, forming probe light and pump light with orthogonal polarization states.

[0073] The atomic gas chamber 10 is located in the optical path of the probe light, receives the normally incident probe light, and absorbs the probe light;

[0074] The reflecting device includes a second reflecting mirror 11 and a third reflecting mirror 12, which reflect the pump light in sequence.

[0075] The third polarization beam splitter is used to reflect the pump light reflected by the third mirror 12 into the atomic gas chamber 10 and recombine it with the probe light to produce an absorption effect. The third polarization beam splitter can allow the absorbed probe light to be transmitted.

[0076] More preferably, the second frequency stabilization unit includes a photodetector 13, a signal source 14, a frequency discriminator 15, a PZT scanning module 16, a PID controller 17, and a high-voltage amplifier 18.

[0077] The photodetector 13 receives the probe light transmitted through the third polarization beam splitter and converts it into an electrical signal;

[0078] Signal source 14 is used to generate the modulation signal;

[0079] Frequency discriminator 15 is used to receive the modulation signal output from the signal source and the electrical signal output from the photodetector, and output an error signal;

[0080] The PZT scanning module 16 is used to scan the laser, determine the saturation absorption peak corresponding to an atomic transition, and output the saturation absorption peak value.

[0081] The PID controller 17 is used to receive the error signal output by the frequency discriminator and output a control quantity;

[0082] The high-voltage amplifier 18 is used to receive the saturated absorption peak, control quantity and modulation signal, and after amplification, feeds them back to the laser to lock the laser output frequency.

[0083] The method for adjusting the laser output frequency based on atomic transitions provided by this invention, such as... Figure 2 As shown, it includes the following steps:

[0084] S1: Output a laser beam using a laser;

[0085] S2: Use a half-wave plate to adjust the polarization direction of the laser, and use a polarization beam splitter to split the laser after the direction is adjusted. After splitting the laser into a high-power laser and a low-power laser, the high-power laser is directly output.

[0086] S3: Use an acousto-optic modulator to perform double frequency shifting on a low-power laser, and use a fiber electro-optic modulator to perform electro-optic modulation on the low-power laser to obtain a low-power laser with altered sideband frequency.

[0087] S4: The polarization direction of the low-power laser after the sideband frequency has been changed is adjusted by using a half-wave plate, and then reflected and transmitted by a polarization beam splitter to form probe light and pump light with orthogonal polarization states.

[0088] S5: Reflect the pump light so that the probe light and pump light act towards each other in the atomic gas cell;

[0089] S6: The probe light is converted into an electrical signal using a photodetector, then converted into an error signal using a frequency discriminator, and finally output as a control signal. This control signal is then fed back to the laser in combination with the saturation absorption peak and the modulation signal, thereby locking the laser output frequency.

[0090] In step S2 above, the low-power laser is used for frequency shifting and frequency stabilization.

[0091] In step S3 above, the low-power laser beam split is reflected by the polarization beam splitter and enters the acousto-optic modulator for the first frequency shift. After the first frequency shift is completed, it passes through a lens and a λ / 4 waveplate, and is reflected by a 0-degree mirror before returning to the acousto-optic modulator for the second frequency shift. The laser beam after the second frequency shift is modulated by the fiber electro-optic modulator, thereby changing the sideband frequency and forming a single-sideband modulated laser.

[0092] In step S4 above, the generated probe light is directed into the atomic gas chamber.

[0093] In step S5 above, pump light is reflected into the atomic gas chamber using two mirrors and a polarizing beam splitter. The direction of propagation of the pump light is opposite to that of the probe light. The pump light and the probe light interact with atoms of the same velocity group in the atomic gas chamber.

[0094] In step S6 above, when providing feedback to the laser, the following is included:

[0095] The PID controller receives the error signal output by the frequency discriminator and outputs a control quantity.

[0096] The laser was scanned using a PZT scanning module, and a saturation absorption peak was determined.

[0097] The error signal, control quantity, and saturation absorption peak are fed back to the laser via a high-voltage amplifier.

[0098] The adjustment method of the present invention further includes: using a microwave frequency source to adjust the driving frequency of the acousto-optic modulator and the fiber electro-optic modulator to adjust the difference between the laser output frequency of the laser and the specified atomic transition frequency, and locking the output frequency of the laser to the atomic transition line corresponding to the saturation absorption peak according to the set frequency difference.

[0099] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to specific embodiments and the accompanying drawings:

[0100] The laser is a 780nm external cavity semiconductor laser, designed to achieve a wide-range, precisely adjustable frequency difference between the laser's output frequency and a hyperfine energy level transition on the D2 line of the Rb-87 atom. For example... Figure 1 As shown, the specific operational procedures for implementing wide-range and high-precision adjustment of the laser output frequency include:

[0101] The laser emitted from the laser is split into a small portion for frequency shifting and stabilization by passing through a λ / 2 waveplate and a PBS (polarizing beam splitter), while the remaining laser power is used for output.

[0102] The low-power laser beam, after being reflected by a polarization beam splitter, enters an acousto-optic modulator, where its +1st order diffracted light (frequency ω+f) AOMAfter passing through a lens and a λ / 4 waveplate, it is reflected by a 0-degree mirror and returns along the same path. After passing through the acousto-optic modulator a second time, it completes a double frequency shift process (laser frequency ω+2f). AOM The distances from the lens to the acousto-optic modulator and the 0-degree reflector are both equal to the focal length of the lens. The microwave frequency source drives the acousto-optic modulator at a frequency f. AOM =110MHz (the frequency adjustment range is limited by the bandwidth of the acousto-optic modulator, usually 110±25MHz).

[0103] After double frequency shifting, the laser enters a fiber-electro-optic modulator (fiber-EOM). After modulation by the fiber-electro-optic modulator, the laser frequency mainly includes three frequency components, with the carrier frequency being ω+2f. AOM The frequency of the +1st-order sideband is ω+2f AOM +f EOM The frequency of the -1st stage sideband is ω+2f AOM -f EOM The driving frequency range of fiber electro-optic modulators is typically 0–10 GHz.

[0104] The laser emitted from the modulation module is split into two beams by a λ / 2 waveplate and a polarization beam splitter. The lower-power portion serves as the probe light, incident directly into the rubidium (Rb) atomic gas chamber. The higher-power portion serves as the pump light, reflected by two mirrors and a polarization beam splitter, and then coincides with the probe light, but the two beams propagate in opposite directions. Both the pump and probe light interact with atoms of the same velocity group within the rubidium atomic gas chamber. The probe light, absorbed by the rubidium atomic gas chamber, is converted into an electrical signal by a photodetector (PD).

[0105] When scanning the frequency of a laser using a piezoelectric ceramic (PZT) scanning module, if the scanning frequency range is sufficiently large and the laser does not skip modes, three sets of saturated absorption spectra can be generated for the same atomic transition (transition frequency set to ω0). These three sets of saturated absorption spectra are generated by the carrier wave and ±1 order sidebands, respectively. Each set of saturated absorption spectrum signals can be independently used by a frequency discriminator to generate an error signal for laser frequency locking.

[0106] When a saturated absorption spectrum is generated by a carrier wave, the laser output frequency satisfies the condition ω = ω0 - 2f. AOM .

[0107] When the saturated absorption spectrum is generated by the +1st order sideband of the fiber electro-optic modulator, the laser output frequency satisfies the condition ω = ω0 - 2f. AOM -f EOM .

[0108] When the saturated absorption spectrum is generated by the -1st order sideband of the fiber electro-optic modulator, the laser output frequency satisfies the condition ω = ω0 - 2f. AOM +fEOM .

[0109] When the driving frequencies of the acousto-optic modulator and the electro-optic modulator satisfy 2f AOM =f EOM At that time, the output frequency of the laser is ω=ω0.

[0110] From the above analysis of the laser output frequency, it can be seen that when a certain reference atomic transition frequency (ω0) is selected, the laser output frequency can be locked to the following frequency values: ω = ω0, ω0 - 2f AOM ,ω0-2f AOM -f EOM ,ω0-2f AOM +f EOM .

[0111] The driving frequency range of the acousto-optic modulator selected in this example is 110±25MHz (center frequency 110MHz, bandwidth 50MHz; these two parameters may vary for different models of acousto-optic modulators).

[0112] The fiber electro-optic modulator selected in this example operates in the frequency range of 0–10 GHz.

[0113] By optimizing the microwave frequency source, the maximum laser frequency shift range that can be achieved in this embodiment is -9830 to 10270 MHz.

[0114] Since the driving frequency range of the fiber electro-optic modulator is 0–10 GHz, the driving frequency of the acousto-optic modulator can be fixed for most of the frequency range in this embodiment, with the sideband frequency shift of the fiber electro-optic modulator being the primary method. Only when the frequency value to be shifted is too close to the atomic transition frequency is the driving frequency of the acousto-optic modulator adjusted to assist in achieving the required laser output frequency.

[0115] By increasing the amplitude of the PZT scanning voltage and appropriately adjusting the PZT bias voltage, three sets of saturated absorption spectra generated by the carrier wave and positive and negative sidebands can be observed without mode hopping in the laser. By decreasing the amplitude of the PZT scanning voltage and appropriately adjusting the PZT bias voltage, one of these saturated absorption spectra can be selected as a reference for laser frequency stabilization. Further decreasing the amplitude of the PZT scanning voltage allows for the selection of a saturated absorption peak corresponding to a single atomic transition. The error signal generated by this absorption peak is then fed back to the laser via a PID controller and a high-voltage amplifier, achieving laser output frequency locking.

[0116] In this embodiment, the laser's output frequency is locked to the selected atomic transition frequency through a certain frequency difference. When it is necessary to change the laser's output frequency, the driving frequency of the acousto-optic modulator and the electro-optic modulator is changed using a microwave frequency source. If the rate of change of the driving frequency is less than the servo bandwidth of the frequency stabilization module, the laser will remain locked. Moreover, the difference between the laser's output frequency and the selected atomic transition frequency can be dynamically set according to requirements.

[0117] In this embodiment, the two control loops of wide-range laser frequency shifting and saturated absorption spectrum frequency stabilization are combined to achieve the goal of large dynamic range and high-precision control of laser frequency.

[0118] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0119] This invention splits the laser output light into two parts. The lower-power portion is frequency-shifted using a combination of an acousto-optic modulator and a fiber electro-optic modulator. The frequency-shifted laser light is then input into a frequency stabilization module. The output signal of the frequency stabilization module provides feedback to the laser, locking the frequency-shifted laser light onto a selected atomic transition line. Changing the driving frequency of the acousto-optic modulator and the fiber electro-optic modulator is equivalent to changing the difference between the laser output light frequency and the atomic transition frequency, thus achieving precise adjustment of the laser output frequency. This invention features simple device, strong robustness, and wide applicability, and can be widely applied in fields such as cold atom physics, quantum optics, and quantum precision measurement and sensing.

[0120] The above embodiments are merely preferred embodiments of the present invention and should not be construed as limiting the scope of protection of the present invention. Any non-substantial changes and substitutions made by those skilled in the art based on the present invention shall fall within the scope of protection claimed by the present invention.

Claims

1. A device for adjusting the output frequency of a laser based on atomic transitions, characterized in that, include: A laser used to output a frequency-shifting laser signal that needs to be stabilized; The modulation module is used to receive the frequency-shifted laser to be stabilized output by the laser, and modulate the frequency of the frequency-shifted laser to be stabilized using radio frequency signals, and output a single-sideband modulated laser. A frequency stabilization module is used to receive the single-sideband modulated laser and generate a frequency discrimination signal. The frequency stabilization module is electrically connected to the laser and feeds back the frequency discrimination signal to the laser to adjust the frequency of the laser output by the laser, so that the single-sideband modulated laser is locked on the selected atomic transition spectral line. The modulation module includes: The input unit is used to adjust the polarization direction of the frequency-shifting laser output by the laser to be stabilized and to split the beam. The frequency shifting unit is used to receive the split beam input from the input unit, and to shift and modulate the split beam to output laser light with a specific sideband frequency; A microwave frequency source is used to drive the frequency shifting unit; The input unit includes: The first half-wave plate is used to adjust the polarization direction of the frequency-shifting laser to be stabilized; The first polarization beam splitter is used to split the frequency-shifting laser beam to be stabilized and frequency-shifted after being adjusted by the first half-wave plate into a high-power laser and a low-power laser. The frequency shifting unit includes: An acousto-optic modulator is used to receive the low-power laser beam split from the first polarization beam splitter and perform a first frequency shift. The acousto-optic modulator is electrically connected to the microwave frequency source and is driven by the microwave frequency source. The first reflecting mirror is used to reflect the laser, which has undergone the first frequency shift, back to the acousto-optic modulator for a second frequency shift; A fiber electro-optic modulator is used to receive beam split light that has undergone a second frequency shift and modulate it to output a single-sideband modulated laser. The fiber electro-optic modulator is electrically connected to the microwave frequency source and is driven by the microwave frequency source. The frequency stabilization module includes: The first frequency stabilization unit is used to receive the single-sideband modulated laser output from the fiber electro-optic modulator and generate a modulation transfer spectrum. The second frequency stabilization unit is used to receive the modulation transfer spectrum output by the first frequency stabilization unit and generate a modulation frequency discrimination signal. The first frequency stabilization unit includes: The second half-wave plate is used to adjust the polarization direction of the single-sideband modulated laser. The second polarization beam splitter is used to receive the single-sideband modulated laser light adjusted by the second half-wave plate, and to cause the single-sideband modulated laser light to be reflected and transmitted to form probe light and pump light with orthogonal polarization states. An atomic gas chamber, located in the optical path of the probe light, receives the normally incident probe light and absorbs it; The reflecting device includes a second reflector and a third reflector, which reflect the pump light in sequence. The third polarization beam splitter is used to reflect the pump light reflected by the third mirror into the atomic gas cell and recombine it with the probe light to produce an absorption effect. The third polarization beam splitter can allow the absorbed probe light to be transmitted. The second frequency stabilization unit includes: A photodetector is used to receive the probe light transmitted through the third polarization beam splitter and convert it into an electrical signal; A signal source, used to generate the modulation signal; A frequency discriminator is used to receive the modulation signal output by the signal source and the electrical signal output by the photodetector, and output an error signal. The PZT scanning module is used to scan the laser, determine the saturation absorption peak corresponding to an atomic transition, and output the saturation absorption peak value. A PID controller is used to receive the error signal output by the frequency discriminator and output a control quantity. A high-voltage amplifier is used to receive the saturated absorption peak, control quantity, and modulation signal, amplify them, and feed them back to the laser to lock the laser output frequency.

2. A method for adjusting the output frequency of a laser based on atomic transitions, according to the apparatus for adjusting the output frequency of a laser based on atomic transitions as described in claim 1, characterized in that, Includes the following steps: Use a laser to output a laser beam; The polarization direction of the laser is adjusted using a half-wave plate, and the laser beam is split into a high-power laser and a low-power laser using a first polarization beam splitter. The high-power laser is then directly output. The low-power laser is subjected to double frequency shifting using an acousto-optic modulator, and then electro-optically modulated using a fiber electro-optic modulator to obtain a low-power laser with altered sideband frequencies. The polarization direction of the low-power laser after the sideband frequency is changed is adjusted by a half-wave plate, and then the second polarization beam splitter is used for reflection and transmission to form probe light and pump light with orthogonal polarization states. The pump light is reflected so that the probe light and the pump light act towards each other in the atomic gas cell; The probe light is converted into an electrical signal using a photodetector, then converted into an error signal using a frequency discriminator, and finally output as a control signal. This control signal is then fed back to the laser in combination with the saturated absorption peak and the modulation signal, thereby locking the laser output frequency. Feedback to the laser includes: The PID controller receives the error signal output by the frequency discriminator and outputs a control quantity. The laser was scanned using a PZT scanning module, and a saturation absorption peak was determined. The modulation signal, control quantity, and saturable absorption peak value are fed back to the laser via a high-voltage amplifier.

3. The method for adjusting the laser output frequency based on atomic transitions according to claim 2, characterized in that, The adjustment method further includes: using a microwave frequency source to adjust the driving frequency of the acousto-optic modulator and the fiber electro-optic modulator to adjust the difference between the laser output frequency of the laser and the specified atomic transition frequency, and locking the output frequency of the laser to the atomic transition spectral line corresponding to the saturation absorption peak according to the set frequency difference.

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