Locking device and method for transfer oscillator of portable optical frequency atomic clock

Abstract

The application discloses a locking device and method for a transfer oscillator of a portable optical frequency atomic clock. The optical comb laser is split into first and second optical comb split lasers, a carrier envelope offset frequency signal is split into first and second carrier envelope offset frequency split signals, the output laser of the laser and the combined laser of the first optical comb split laser are detected by a first photoelectric detector to obtain a beat frequency signal, the second optical comb split laser is detected by a second photoelectric detector to obtain a repetition frequency signal, and the repetition frequency signal is split into first and second repetition frequency split signals. Then, the frequency synthesis circuit, the frequency synthesis circuit, the first phase-locked loop and the second phase-locked loop are sequentially used to generate a phase-locked loop feedback signal and output the phase-locked loop feedback signal to an optical frequency comb. The frequency of the optical comb laser output by the optical frequency comb and the carrier envelope offset frequency signal is locked, so that long-term stable operation of the system can be realized and high-performance optical signal output can be maintained.

Description

Technical Field

[0001] This invention belongs to the field of optical frequency atomic clock technology, specifically relating to a locking device and method for a transmission oscillator in a portable optical frequency atomic clock. Background Technology

[0002] Compared to traditional microwave atomic clocks, optical frequency atomic clocks have transition frequencies 4-5 orders of magnitude higher, resulting in a significant advantage in frequency accuracy. Unlike microwave atomic clocks, optical frequency atomic clocks output optical signals, which cannot be directly read by a frequency counter. Therefore, this optical signal needs to be frequency-divided and converted to microwave radio frequency. Currently, the mainstream tool for achieving optical-to-microwave frequency transfer is the optical frequency comb. Typically, the carrier envelope offset frequency and the optical frequency reference of the optical frequency comb are phase-locked with the beat frequency of the optical frequency comb to a repetition frequency. At this point, the repetition frequency signal has the same performance as the optical frequency reference. The repetition frequency of the optical frequency comb is usually in the hundreds of megahertz range and can be directly detected; therefore, the repetition frequency signal is the signal output by the optical frequency reference, realizing optical-to-microwave frequency conversion. However, this method requires at least two high-speed phase-locked loops to achieve full locking of the carrier envelope offset frequency and the beat frequency, increasing system complexity. More importantly, the coupling effect between the phase-locked loops can interfere with each other during high-speed phase-locking, reducing the reliability of the phase-locked system. This coupling effect is more pronounced in widely used fiber-optic optical frequency comb systems. While the down-conversion scheme based on the transfer oscillator principle can achieve stable transfer of the optical frequency reference to the RF signal in a fully free-running optical frequency comb state, avoiding the coupling effects between multiple phase-locked loops, the fully free-running optical frequency comb is susceptible to environmental factors (such as temperature). This is especially true for portable optical atomic clocks, which typically require long-term operation under varying ambient temperatures. This can cause the carrier envelope offset frequency and beat frequency to drift out of the operating range of the RF bandpass filter in the system, leading to the transfer oscillator malfunctioning and affecting system reliability and long-term stability. Furthermore, although the transfer oscillator scheme achieves down-conversion from the optical frequency reference to the microwave, the entire optical frequency comb is in a fully free-running state, making it impossible to provide users with a locked optical frequency comb signal. Summary of the Invention

[0003] To address the issue of long-term operational stability of optical frequency atomic clocks, this invention provides a locking device and method for the transmission oscillator of a portable optical frequency atomic clock.

[0004] The above-mentioned objectives of the present invention are achieved through the following technical means:

[0005] A locking device for the transmission oscillator of a portable optical frequency atomic clock includes a laser, a frequency synthesis circuit, and an optical frequency comb.

[0006] An optical frequency comb outputs a combed laser and a carrier envelope offset frequency signal. The combed laser is split into a first-comb split laser and a second-comb split laser. The carrier envelope offset frequency signal is further divided into a first-carrier-envelope-offset-frequency-power-divided signal and a second-carrier-envelope-offset-frequency-power-divided signal.

[0007] The combined laser beam from the emitted laser and the first optical comb-splitter laser is detected by a first photodetector to obtain a beat frequency signal. The second optical comb-splitter laser is detected by a second photodetector to obtain a repetition frequency signal. The repetition frequency signal is then divided into a first repetition frequency power-divided signal and a second repetition frequency power-divided signal.

[0008] The frequency synthesis circuit uses the frequencies of the beat frequency signal, the first repetition frequency power divider signal, and the first carrier envelope offset frequency power divider signal as the beat frequency, respectively. repetition frequency and carrier envelope offset frequency ,calculate The frequency of the frequency synthesis signal is used as the power divider, and then the output is a first frequency synthesis signal, a second frequency synthesis signal, and a third frequency synthesis signal.

[0009] The first phase-locked circuit generates a feedback signal based on the second carrier envelope offset frequency power divider signal and the second frequency composite signal, which is then input to the pump current modulation input terminal of the optical frequency comb; the second phase-locked circuit generates a feedback signal based on the third frequency composite signal and the second repetition frequency power divider signal, which is then input to the piezoelectric ceramic voltage input terminal of the optical frequency comb.

[0010] As described above, the optical comb laser is split into a first optical comb split laser and a second optical comb split laser by a laser beam splitter.

[0011] As described above, the carrier envelope offset frequency signal is divided into a first carrier envelope offset frequency power-divided signal and a second carrier envelope offset frequency power-divided signal by the first radio frequency power divider.

[0012] As described above, the emitted laser from the laser and the first optical comb split laser are combined into a single laser beam by a laser beam combiner.

[0013] As described above, the repetition frequency signal is divided into a first repetition frequency power-divided signal and a second repetition frequency power-divided signal by the second radio frequency power divider.

[0014] As described above, the first phase-locked circuit divides the second carrier envelope offset frequency power divider signal to the frequency of the second frequency composite signal, performs phase detection on the divided second carrier envelope offset frequency power divider signal and the second frequency composite signal, and generates a feedback signal for the first phase-locked circuit.

[0015] As described above, the second phase-locked circuit divides the second repetition frequency power-dividing signal to the frequency of the third frequency composite signal, performs phase detection on the divided second repetition frequency power-dividing signal and the third frequency composite signal, and generates a feedback signal for the second phase-locked circuit.

[0016] A locking method for the transfer oscillator of a portable optical frequency atomic clock includes the following steps:

[0017] An optical frequency comb outputs a combed laser and a carrier envelope offset frequency signal. The combed laser is split into a first-comb split laser and a second-comb split laser. The carrier envelope offset frequency signal is further divided into a first-carrier-envelope-offset-frequency-power-divided signal and a second-carrier-envelope-offset-frequency-power-divided signal.

[0018] The combined laser beam from the emitted laser and the first optical comb-splitter laser is detected by a first photodetector to obtain a beat frequency signal. The second optical comb-splitter laser is detected by a second photodetector to obtain a repetition frequency signal. The repetition frequency signal is then divided into a first repetition frequency power-divided signal and a second repetition frequency power-divided signal.

[0019] The frequencies of the beat frequency signal, the first repetition frequency power division signal, and the first carrier envelope offset frequency power division signal are respectively used as the beat frequency. repetition frequency and carrier envelope offset frequency ,calculate The frequency of the frequency synthesis signal is used as the power divider, and then the output is a first frequency synthesis signal, a second frequency synthesis signal, and a third frequency synthesis signal.

[0020] The second carrier envelope offset frequency power divider signal is divided to the frequency of the second frequency composite signal. The divided second carrier envelope offset frequency power divider signal and the second frequency composite signal are phase-discriminated to generate a first phase-locked loop circuit feedback signal, which is input to the pump current modulation input terminal of the optical frequency comb.

[0021] The second repetition frequency power divider signal is divided to the frequency of the third frequency composite signal. The second repetition frequency power divider signal and the third frequency composite signal are phase-detected to generate a second phase-locked circuit feedback signal, which is input to the piezoelectric ceramic voltage input terminal of the optical frequency comb.

[0022] Compared with the prior art, the present invention has the following advantages:

[0023] Under the premise of avoiding mutual coupling between control loops, the performance of the optical frequency reference (emitted laser) is transmitted to the radio frequency signals (first repetition frequency power divider signal, second repetition frequency power divider signal, first carrier envelope offset frequency power divider signal, and second carrier envelope offset frequency power divider signal); then, the optical frequency comb is fully locked by two nearly uncoupled feedback loops (the loop that outputs the feedback signals of the first phase-locked circuit and the second phase-locked circuit).

[0024] This invention locks the frequencies of the optical comb laser (repetition frequency) and the carrier envelope offset frequency signal output by the optical frequency comb, thereby achieving long-term stable operation of the system and maintaining high-performance optical signal output. Furthermore, since locking the repetition frequency of the optical comb laser does not require rapid adjustment of the beat frequency locking, it can be accomplished using only piezoelectric ceramic (PZT). The repetition frequency signal has lower noise, thus requiring less loop bandwidth for locking. PZT, with its smaller bandwidth, can be used. However, the beat frequency has high noise, making it impossible to use only PZT for locking. Attached Figure Description

[0025] Figure 1 This is a schematic diagram of the locking device for the transmission oscillator of a portable optical frequency atomic clock.

[0026] 1-Laser; 2-Laser beam combiner; 3-Optical frequency comb; 4-Laser beam splitter; 5-First photodetector; 6-Second photodetector; 7-First RF power divider; 8-Second RF power divider; 9-First phase-locked loop circuit; 10-Second phase-locked loop circuit; 11-Frequency synthesis circuit; 12-Outgoing laser; 21-Beam-combined laser; 31-Optical comb laser; 32-Carrier envelope offset frequency signal; 41-First optical comb beam-splitting laser; 42-Second optical comb beam-splitting laser; 51-Beat frequency signal; 61-Repetition frequency signal; 71-First carrier envelope offset frequency power divider signal; 72-Second carrier envelope offset frequency power divider signal; 81-First repetition frequency power divider signal; 82-Second repetition frequency power divider signal; 91-First phase-locked loop circuit feedback signal; 101-Second phase-locked loop circuit feedback signal; 110-First frequency synthesis signal; 111-Second frequency synthesis signal; 112-Third frequency synthesis signal. Detailed Implementation

[0027] To facilitate understanding and implementation of the present invention by those skilled in the art, the present invention will be further described in detail below with reference to implementation examples. It should be understood that the implementation examples described herein are for illustration and explanation only and are not intended to limit the present invention.

[0028] Example 1:

[0029] like Figure 1As shown, this is a locking device for the transmission oscillator of a portable optical frequency atomic clock. An optical frequency comb 3 outputs a comb laser 31 and a carrier envelope offset frequency signal 32. An outgoing laser 12 (reference light) is output from laser 1. The comb laser 31 is incident on a laser beam splitter 4. The laser beam splitter 4 outputs a first comb-splitter laser 41 and a second comb-splitter laser 42. The first comb-splitter laser 41 and the outgoing laser 12 are respectively input to the two input ports of a laser beam combiner 2. The beat frequency laser 21 output from the laser beam combiner 2 is input to a first photodetector 5. The first photodetector 5 outputs a beat frequency signal 51 to a frequency synthesis circuit 11. The second comb-splitter laser 42 is input to a second photodetector 6. The second photodetector 6 outputs a repetition frequency signal 61 to a second radio frequency power divider 8. The second radio frequency power divider 8 outputs a first repetition frequency power divider signal 81 and a second repetition frequency power divider signal 82. The first repetition frequency power divider signal 81 is input to the frequency synthesis circuit 11, and the second repetition frequency power divider signal 82 is input to the second phase-locked loop circuit 10. Signal 32 is input to the first RF power divider 7. The first RF power divider 7 outputs a first carrier envelope offset frequency power divider signal 71 and a second carrier envelope offset frequency power divider signal 72. The first carrier envelope offset frequency power divider signal 71 is input to the frequency synthesis circuit 11. The second carrier envelope offset frequency power divider signal 72 is input to the first phase-locked circuit 9. The frequency synthesis circuit 11 outputs a first frequency synthesis signal 110, a second frequency synthesis signal 111, and a third frequency synthesis signal 112. The second frequency synthesis signal 111 is input to the first phase-locked circuit 9. The third frequency synthesis signal 112 is input to the second phase-locked circuit 10. The first phase-locked circuit 9 outputs a first phase-locked circuit feedback signal 91 to the pump current modulation input terminal of the optical frequency comb 3. The second phase-locked circuit 10 outputs a second phase-locked circuit feedback signal 101 to the piezoelectric ceramic voltage input terminal of the optical frequency comb 3. The first frequency synthesis signal 110 serves as the output RF signal for transmitting the oscillator fully locked device.

[0030] The working principle of this invention is as follows. Furthermore, the signal processing methods described below are only for better explaining the working principle of this invention; the method of this invention is equally applicable to optical frequency combs of various structures and radio frequency signals of different polarities.

[0031] For any optical frequency comb, the frequency of any single optical frequency comb tooth can be expressed as... ,in, For optical frequency comb Frequency of root comb teeth, The carrier envelope offset frequency, This is the repetition frequency of the optical frequency comb. When the optical frequency comb is aligned with the reference light (the reference light frequency is...),... During beat frequency, a beat frequency is generated. Therefore, the reference optical frequency It can be represented by the frequency of an optical frequency comb, i.e. .

[0032] Divide both sides of the formula by the number of comb teeth. You can get The frequency on the left side of the formula is the frequency of the reference light. Frequency division has the same performance as the reference light; the right side shows the carrier envelope offset frequency. With beat frequency and Frequency division and optical frequency comb repetition frequency The sum of these three RF signals allows for frequency synthesis to obtain an RF signal with the same performance as the reference light. Clearly, this process involves only frequency division and synthesis of the first carrier envelope offset frequency power divider signal 71 (obtained from the carrier envelope offset frequency signal 32 output by the optical frequency comb), the first repetition frequency power divider signal 81 (obtained from the repetition frequency signal 61), and the beat frequency signal 51, without requiring any locking system. The frequency conversion from light to microwave can be achieved through the frequency synthesis circuit, significantly reducing system complexity. However, since the optical frequency comb is always in a free-running state, its state is unstable and it cannot output a stable optical comb laser 31. Furthermore, during prolonged operation, the frequency drift of the three RF signals (first repetition frequency power divider signal 81, beat frequency signal 51, and first carrier envelope offset frequency power divider signal 71) will cause the frequency synthesis circuit to malfunction, resulting in abnormal output signals.

[0033] Furthermore, the radio frequency signals (second frequency synthesis signal 111 and third frequency synthesis signal 112) output by the aforementioned frequency synthesis circuit 11, which have the performance of reference light (emitted laser 12), are used as reference signals for the first phase-locked circuit 9 and the second phase-locked circuit 10. This locks the frequencies of the optical comb laser 31 (repetition frequency) output by the optical frequency comb 3 and the carrier envelope offset frequency signal 32, thus achieving long-term stable operation of the system and maintaining high-performance optical signal output. Simultaneously, since locking the repetition frequency of the optical comb laser 31 does not require rapid adjustment of the beat frequency locking, it can be accomplished using only piezoelectric ceramics (PZT). The repetition frequency signal has lower noise, therefore the loop bandwidth requirement during locking is smaller, and piezoelectric ceramics (PZT) with smaller bandwidth can be used. Beat frequency has high noise, so locking cannot be achieved using only piezoelectric ceramics (PZT). In this scheme, the third frequency synthesis signal 112 and the first frequency synthesis signal 110 are the same signal, both generated after synthesis, and their frequency is the frequency of the reference light. Frequency division, its noise is only related to the reference light. The noise of each signal of the optical frequency comb has been canceled in the synthesis process. Only the repetition frequency of the optical comb laser 31 is locked, and the beat frequency is not locked. This is an important difference from the traditional full-lock scheme. The piezoelectric ceramic PZT has little effect on the carrier envelope offset frequency, so it can avoid the instability caused by the mutual influence of the locking loops in the full-lock scheme.

[0034] The specific working process is as follows: The emitted laser 12 from laser 1 enters laser beam combiner 2. The optical frequency comb laser 31 from optical frequency comb 3 enters laser beam splitter 4. Laser beam splitter 4 splits the optical frequency comb laser into beams, outputting first optical frequency comb split laser 41 and second optical frequency comb split laser 42. Both the first optical frequency comb split laser 41 and the emitted laser 12 enter laser beam combiner 2. Laser beam combiner 2 outputs beat frequency laser 21 to first photodetector 5. First photodetector 5 detects beat frequency laser 21 and generates beat frequency signal 51, which enters frequency synthesis circuit 11.

[0035] Furthermore, the first photodetector 5 is preferably a balanced detector with two optical inputs, which has the function of eliminating common-mode noise, reducing the amplitude of the repetition frequency signal generated during the beat frequency process, and improving the signal-to-noise ratio of the beat frequency.

[0036] The second optical comb-splitter laser 42 enters the second photodetector 6. The second photodetector 6 detects the second optical comb-splitter laser 42 and outputs a repetition frequency signal 61 to the second RF power divider 8. The second RF power divider 8 splits the input repetition frequency signal 61 into a first repetition frequency power divider signal 81 and a second repetition frequency power divider signal 82 of equal power. The first repetition frequency power divider signal 81 is input to the frequency synthesis circuit 11, and the second repetition frequency power divider signal 82 is input to the second phase-locked loop circuit 10. The optical frequency comb 3 outputs a carrier envelope offset frequency signal 32, which enters the first RF power divider 7. The first RF power divider 7 splits the input carrier envelope offset frequency signal 32 into a first carrier envelope offset frequency power divider signal 71 and a second carrier envelope offset frequency power divider signal 72 of equal power. The first carrier envelope offset frequency power divider signal 71 is input to the frequency synthesis circuit 11, and the second carrier envelope offset frequency power divider signal 72 is input to the first phase-locked loop circuit 9. The frequency synthesis circuit 11 outputs signal 111 to the first phase-locked circuit 9, and the frequency synthesis circuit 11 outputs signal 112 to the second phase-locked circuit 10.

[0037] Furthermore, the first phase-locked circuit 9 and the second phase-locked circuit 10 internally have frequency division functions. The first phase-locked circuit 9 is used to divide the second carrier envelope offset frequency power-dividing signal 72 to the frequency of the second frequency composite signal 111 (reference signal frequency), and the second phase-locked circuit 10 is used to divide the second repetition frequency power-dividing signal 82 to the frequency of the third frequency composite signal 112 (reference signal frequency). The purpose of frequency division is to perform phase detection on the signal, which requires that the frequencies of the two input signals to the phase-locked circuits be approximately the same. The frequency division coefficient of the frequency divider inside the first phase-locked circuit 9 is... The frequency division coefficient of the frequency divider inside the second phase-locked loop circuit 10 Adjusted to: and , , , as well as These are the frequencies of the second carrier envelope offset frequency power divider signal 72, the second repetition frequency power divider signal 82, the second frequency composite signal 111, and the third frequency composite signal 112, respectively. The second frequency composite signal 111 and the third frequency composite signal 112 are signals with the same frequency as the final output signal 110 of the system, and their frequencies are generally 10 MHz. Therefore, it is only necessary to determine the frequencies of the second carrier envelope offset frequency power divider signal 72 and the second repetition frequency power divider signal 82.

[0038] The first phase-locked circuit 9 performs phase detection on the second carrier envelope offset frequency power divider signal 72 and the second frequency synthesis signal 111 after frequency division. Then, the servo generates the first phase-locked circuit feedback signal 91, which is input to the pump current modulation input terminal of the optical frequency comb 3 for phase locking of the carrier envelope offset frequency of the optical frequency comb 3. The purpose here is to perform phase detection on the carrier envelope offset frequency signal and the reference signal, so phase locking of the carrier envelope offset frequency is performed.

[0039] The second phase-locked circuit 10 performs phase detection on the second repetition frequency power divider signal 82 and the third frequency composite signal 112 after frequency division. Then, it generates a feedback signal 101 for the second phase-locked circuit via a servo and inputs it to the piezoelectric ceramic voltage input terminal of the optical frequency comb 3 for phase locking of the repetition frequency of the optical frequency comb 3. The purpose here is to perform phase detection between the repetition frequency signal and the reference signal, so phase locking of the repetition frequency is performed.

[0040] The frequency synthesis circuit 11 processes the input beat frequency signal 51, the first repetition frequency power divider signal 81, and the first carrier envelope offset frequency power divider signal 71 as follows: the frequencies of the filtered and amplified beat frequency signal 51, the first repetition frequency power divider signal 81, and the first carrier envelope offset frequency power divider signal 71 are respectively used as the beat frequency. repetition frequency and carrier envelope offset frequency Based on the formula Calculate the frequency of the reference light Frequency division The signal is a frequency-synthesized signal, in which, Number of comb teeth Reference optical frequency, Reference optical frequency If the frequency is too high, it cannot be directly used for RF signal synthesis. The frequency synthesis signal is an RF signal with optical reference performance. After power division, the frequency synthesis signal is output as a first frequency synthesis signal 110, a second frequency synthesis signal 111, and a third frequency synthesis signal 112. The second frequency synthesis signal 111 is input to the first phase-locked circuit 9 as a phase-locked reference signal, and the third frequency synthesis signal 112 is input to the second phase-locked circuit 10 as a phase-locked reference signal. The first frequency synthesis signal 110 is the output RF signal of the transmission oscillator fully locked device.

[0041] Furthermore, the frequency synthesis circuit 11 should have a frequency division function to divide the output first frequency synthesis signal 110, second frequency synthesis signal 111, and third frequency synthesis signal 112 to the standard radio frequency reference frequency of 10 MHz.

[0042] Example 2:

[0043] A locking method for the transfer oscillator of a portable optical frequency atomic clock includes the following steps:

[0044] The optical frequency comb 3 outputs a comb laser 31 and a carrier envelope offset frequency signal 32. The comb laser 31 is split to obtain a first comb-splitter laser 41 and a second comb-splitter laser 42. The carrier envelope offset frequency signal 32 is divided into a first carrier envelope offset frequency power-divided signal 71 and a second carrier envelope offset frequency power-divided signal 72.

[0045] The emitted laser 12 from laser 1 and the combined laser 21 from the first optical comb-splitter 41 are detected by the first photodetector 5 to obtain a beat frequency signal 51. The second optical comb-splitter 42 is detected by the second photodetector 6 to obtain a repetition frequency signal 61. The repetition frequency signal 61 is then divided into a first repetition frequency power-divided signal 81 and a second repetition frequency power-divided signal 82.

[0046] The frequencies of the beat frequency signal 51, the first repetition frequency power distribution signal 81, and the first carrier envelope offset frequency power distribution signal 71 are respectively used as the beat frequency. repetition frequency and carrier envelope offset frequency ,calculate The frequency of the frequency synthesis signal is used as the frequency of the frequency synthesis signal. After power division, the frequency synthesis signal is output as a first frequency synthesis signal 110, a second frequency synthesis signal 111, and a third frequency synthesis signal 112.

[0047] The second carrier envelope offset frequency power divider signal 72 is divided to the frequency of the second frequency composite signal 111. The divided second carrier envelope offset frequency power divider signal 72 and the second frequency composite signal 111 are phase-discriminated to generate a first phase-locked loop feedback signal 91, which is input to the pump current modulation input terminal of the optical frequency comb 3.

[0048] The second repetition frequency power divider signal 82 is divided to the frequency of the third frequency composite signal 112. The second repetition frequency power divider signal 82 and the third frequency composite signal 112 are phase-detected to generate a second phase-locked loop feedback signal 101, which is input to the piezoelectric ceramic voltage input terminal of the optical frequency comb 3.

[0049] It should be noted that the embodiments described in this invention are merely illustrative of the spirit of the invention. Those skilled in the art to which this invention pertains can make various modifications or additions to the described embodiments or use similar methods to substitute them, without departing from the spirit of the invention or exceeding the scope defined by the appended claims.

Claims

1. A locking device for a transmission oscillator of a portable optical frequency atomic clock, comprising a laser (1), characterized in that, It also includes a frequency synthesis circuit (11) and an optical frequency comb (3). The optical frequency comb (3) outputs a comb laser (31) and a carrier envelope offset frequency signal (32). The comb laser (31) is split to obtain a first comb split laser (41) and a second comb split laser (42). The carrier envelope offset frequency signal (32) is divided into a first carrier envelope offset frequency power split signal (71) and a second carrier envelope offset frequency power split signal (72). The laser emitted from the laser (12) and the combined laser (21) of the first optical comb beam splitter (41) are detected by the first photodetector (5) to obtain the beat frequency signal (51). The laser of the second optical comb beam splitter (42) is detected by the second photodetector (6) to obtain the repetition frequency signal (61). The repetition frequency signal (61) is divided into the first repetition frequency power division signal (81) and the second repetition frequency power division signal (82). The frequency synthesis circuit (11) uses the frequencies of the beat frequency signal (51), the first repetition frequency power divider signal (81), and the first carrier envelope offset frequency power divider signal (71) as the beat frequencies, respectively. repetition frequency and carrier envelope offset frequency ,calculate As the frequency of the frequency synthesis signal, the frequency synthesis signal is divided into a first frequency synthesis signal (110), a second frequency synthesis signal (111), and a third frequency synthesis signal (112). The first phase-locked circuit (9) generates a first phase-locked circuit feedback signal (91) based on the second carrier envelope offset frequency power divider signal (72) and the second frequency composite signal (111), which is input to the pump current modulation input terminal of the optical frequency comb (3); the second phase-locked circuit (10) generates a second phase-locked circuit feedback signal (101) based on the third frequency composite signal (112) and the second repetition frequency power divider signal (82), which is input to the piezoelectric ceramic voltage input terminal of the optical frequency comb (3).

2. The locking device for the transmission oscillator of a portable optical frequency atomic clock according to claim 1, characterized in that, The optical comb laser (31) is split into a first optical comb split laser (41) and a second optical comb split laser (42) by a laser beam splitter (4).

3. The locking device for the transmission oscillator of a portable optical frequency atomic clock according to claim 1, characterized in that, The carrier envelope offset frequency signal (32) is divided into a first carrier envelope offset frequency power divider (71) and a second carrier envelope offset frequency power divider (72) by the first radio frequency power divider (7).

4. The locking device for the transmission oscillator of a portable optical frequency atomic clock according to claim 1, characterized in that, The laser emitted from the laser (12) and the first optical comb split laser (41) are combined into a combined laser (21) by the laser combiner (2).

5. The locking device for the transmission oscillator of a portable optical frequency atomic clock according to claim 1, characterized in that, The repetition frequency signal (61) is divided into a first repetition frequency power divider signal (81) and a second repetition frequency power divider signal (82) by the second radio frequency power divider (8).

6. The locking device for the transmission oscillator of a portable optical frequency atomic clock according to claim 1, characterized in that, The first phase-locked circuit (9) divides the second carrier envelope offset frequency power divider signal (72) to the frequency of the second frequency composite signal (111), performs phase detection on the second carrier envelope offset frequency power divider signal (72) and the second frequency composite signal (111) after frequency division, and generates the first phase-locked circuit feedback signal (91).

7. The locking device for the transmission oscillator of a portable optical frequency atomic clock according to claim 1, characterized in that, The second phase-locked circuit (10) divides the second repetition frequency power divider signal (82) to the frequency of the third frequency composite signal (112), performs phase detection on the second repetition frequency power divider signal (82) and the third frequency composite signal (112) after frequency division, and generates a second phase-locked circuit feedback signal (101).

8. A locking method for the transfer oscillator of a portable optical frequency atomic clock, characterized in that, Includes the following steps: The optical frequency comb (3) outputs a comb laser (31) and a carrier envelope offset frequency signal (32). The comb laser (31) is split to obtain a first comb split laser (41) and a second comb split laser (42). The carrier envelope offset frequency signal (32) is divided into a first carrier envelope offset frequency power split signal (71) and a second carrier envelope offset frequency power split signal (72). The laser emitted from the laser (12) and the combined laser (21) of the first optical comb beam splitter (41) are detected by the first photodetector (5) to obtain the beat frequency signal (51). The laser of the second optical comb beam splitter (42) is detected by the second photodetector (6) to obtain the repetition frequency signal (61). The repetition frequency signal (61) is divided into the first repetition frequency power division signal (81) and the second repetition frequency power division signal (82). The frequencies of the beat frequency signal (51), the first repetition frequency power distribution signal (81), and the first carrier envelope offset frequency power distribution signal (71) are respectively used as the beat frequency. repetition frequency and carrier envelope offset frequency ,calculate As the frequency of the frequency synthesis signal, the frequency synthesis signal is divided into a first frequency synthesis signal (110), a second frequency synthesis signal (111), and a third frequency synthesis signal (112). The second carrier envelope offset frequency power divider signal (72) is divided to the frequency of the second frequency composite signal (111). The divided second carrier envelope offset frequency power divider signal (72) and the second frequency composite signal (111) are phase-discriminated to generate a first phase-locked loop feedback signal (91), which is input to the pump current modulation input terminal of the optical frequency comb (3). The second repetition frequency power divider signal (82) is divided to the frequency of the third frequency composite signal (112). The second repetition frequency power divider signal (82) and the third frequency composite signal (112) after frequency division are phase-detected, and the second phase-locked circuit feedback signal (101) is generated and input to the piezoelectric ceramic voltage input terminal of the optical frequency comb (3).

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