Laser regulation and control device for clock

Abstract

The invention discloses a clock laser regulation and control device. A clock laser source in the device is connected with a first port of a laser beam splitting module; a second port of the laser beam splitting module is connected with a first port of the quantum state inquiry regulation and control module; a third port of the laser beam splitting module is connected with a first port of the phase elimination module; and a second port of the phase elimination module is connected with a second port of the quantum state inquiry regulation and control module. The laser beam splitting module splits the initial light beam into a first initial light beam and a second initial light beam; the phase elimination module performs phase locking on the second initial light beam to generate a reference light beam; the quantum state inquiry regulation and control module generates a modulation light beam based on the first initial light beam and the reference light beam; performing time sequence regulation and control on the propagation direction of the modulated light beam to obtain a first target light beam and a second target light beam which are alternately output; attenuating the first target light beam to obtain a third target light beam; and controlling the third target light beam and the second target light beam to be output from a third port of the quantum state inquiry regulation and control module.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of optical technology, in particular to a clock laser regulation device. BACKGROUND

[0002] The optical clock takes the photon frequency generated by the electron energy level transition as the time reference, and uses the transition of the internal electron of the atom between different energy levels to define time.

[0003] In the optical clock system, Rabi interrogation and Ramsey interrogation are two mainstream measurement methods. Rabi interrogation has the advantages of strong robustness and easy to accurately lock the resonance frequency, but it is easy to introduce Dick effect noise, resulting in low system stability. Ramsey interrogation has the advantage of weakening Dick effect noise, but has the disadvantage of requiring strict initial frequency alignment accuracy, and the measurement error increases due to large frequency deviation in the initial stage of resonance frequency locking.

[0004] Therefore, how to combine the technical advantages of the two interrogation methods to improve the performance of the optical clock system is of great value and significance for mobile optical clocks and space optical clocks. SUMMARY

[0005] Based on the above problems, the present application provides a clock laser regulation device, which can be compatible with Rabi interrogation and Ramsey interrogation, and can improve the performance of the optical clock system.

[0006] The embodiments of the present application disclose the following technical solutions:

[0007] The present application discloses a clock laser regulation device, which comprises a clock laser source, a laser beam splitting module, a quantum state interrogation regulation module and a phase elimination module.

[0008] The clock laser source is connected with the first port of the laser beam splitting module; the second port of the laser beam splitting module is connected with the first port of the quantum state interrogation regulation module; the third port of the laser beam splitting module is connected with the first port of the phase elimination module; and the second port of the phase elimination module is connected with the second port of the quantum state interrogation regulation module.

[0009] The laser beam splitting module is used for splitting the initial light beam output by the clock laser source into a first initial light beam and a second initial light beam.

[0010] The phase elimination module is used for phase locking the received second initial light beam to generate a reference light beam.

[0011] The quantum state interrogation regulation module is configured to generate a modulation light beam based on the first initial light beam and the reference light beam, time sequence regulate a propagation direction of the modulation light beam to obtain a first target light beam and a second target light beam alternately output, attenuate light intensity of the first target light beam to obtain a third target light beam, and control the third target light beam and the second target light beam to be output from a third port of the quantum state interrogation regulation module.

[0012] Compared with the prior art, the clock laser regulation device disclosed in the application is compatible with Rabi interrogation and Ramsey interrogation. When Rabi interrogation and Ramsey interrogation are periodically applied to an atomic group, the resonance frequency can be accurately locked by means of Rabi interrogation, and Dick effect noise can be effectively weakened by means of Ramsey interrogation, so that the technical advantages of the two kinds of interrogation methods are fully utilized, and the stability and measurement accuracy of the optical clock system are significantly improved. BRIEF DESCRIPTION OF DRAWINGS

[0013] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the drawings needed to be used in the embodiments or the prior art description will be briefly introduced. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can be obtained by those skilled in the art without creative labor.

[0014] Figure 1 A structural schematic diagram of a clock laser regulation device provided by an embodiment of the present application is shown in the figure.

[0015] Figure 2 A structural schematic diagram of a light splitting combination unit provided by an embodiment of the present application is shown in the figure.

[0016] Figure 3 A structural schematic diagram of a phase elimination module provided by an embodiment of the present application is shown in the figure. DETAILED DESCRIPTION

[0017] An optical clock system refers to a complex experimental device and technical system for realizing ultra-high precision time measurement by taking optical frequency band energy level transition of atoms or ions as a reference through laser technology. Interrogation refers to an experimental operation of exciting atomic transition by laser and measuring the corresponding laser frequency, so as to capture the atomic energy level transition frequency. In the optical clock system, Rabi interrogation and Ramsey interrogation are two mainstream measurement methods.

[0018] Rabi interrogation refers to a way of interrogation that after an atom is prepared at a specific energy level, the atom is irradiated using a π pulse, when the frequency thereof is close to the frequency of the energy level transition of the atom, the probability of the atom jumping is detected.

[0019] The Rabi interrogation scheme is simple, and high excitation rate transition phenomenon only occurs when the laser frequency is resonant with the atomic transition, which is conducive to the optical clock system to accurately find the resonant transition frequency, so that the optical clock closed-loop feedback loop is more robust. However, in the Rabi interrogation method, the sensitivity function of the atomic transition to the clock laser noise is limited, which increases the Dick effect noise of the optical clock system and limits the system stability of the atomic optical clock. That is, the Rabi interrogation has the advantages of strong robustness and precise locking of the resonant frequency, and the disadvantages of easy introduction of Dick effect noise and low system stability.

[0020] Ramsey interrogation is a way of interrogation that after an atom is prepared at a specific energy level, the atom is irradiated using a first π / 2 pulse, so that the atom is in a quantum superposition state. Then the quantum state is allowed to evolve freely for a period of time, and the phase evolution of the ground state and the excited state is related to the frequency mismatch of the light pulse. Then the atom is irradiated using a second π / 2 pulse. Finally, the probability of the atom jumping is detected.

[0021] The sensitivity function of the Ramsey interrogation is close to a rectangular function, which has the advantage of weakening the Dick effect noise. When two sets of atomic systems perform alternating Ramsey interrogation, a clock with no dead time is formed, and the Dick effect noise can be almost completely suppressed, greatly improving the stability of the optical clock system. However, the first and second π / 2 pulses in the Ramsey interrogation need to be phase matched. When the light pulse is turned off during the free evolution of the atom, there is a 50% probability that the second π / 2 pulse will have a π phase jump, which will cause the Ramsey interrogation to fail. The Ramsey interrogation also has the disadvantages of strict requirement for initial frequency alignment accuracy and easy increase of measurement error due to excessive frequency deviation in the initial stage of resonant frequency locking. That is, the Ramsey interrogation has the advantages of weakening the Dick effect noise, and the disadvantages of phase jump leading to interrogation failure, strict requirement for initial frequency alignment accuracy, and easy increase of measurement error due to excessive frequency deviation in the initial stage of resonant frequency locking.

[0022] In addition, for a narrow linewidth atomic spectrum line with a linewidth of 1 Hz, the time of the π pulse required in the Rabi interrogation is 500 ms. In the Ramsey interrogation, the free evolution time is usually set to 500 ms, and the π pulse time is controlled to be 5-50 ms. This means that the light intensity of the Ramsey interrogation is approximately 100 times to 10,000 times that of the Rabi interrogation. This leads to the fact that the Ramsey interrogation and the Rabi interrogation cannot be compatible in the same optical scheme.

[0023] How to solve the phase jump of Ramsey probe pulse in optical clock system, the incompatibility of Ramsey probe with Rabi probe optical scheme, and at least part of the problems in meeting the miniaturization requirements of optical clock system have become one of the problems to be solved in the field of mobile optical clock and space optical clock.

[0024] To solve at least part of the above problems, the application discloses a clock laser regulation device, which comprises a clock laser source, a laser beam splitting module, a quantum state probe regulation module and a phase elimination module. The laser beam splitting module is used to divide the initial light beam output by the clock laser source into a first initial light beam and a second initial light beam; the phase elimination module is used to phase lock the received second initial light beam to generate a reference light beam; the quantum state probe regulation module is used to generate a modulated light beam based on the first initial light beam and the reference light beam; the propagation direction of the modulated light beam is time-sequentially regulated to obtain alternating first target light beams and second target light beams; the light intensity of the first target light beam is attenuated to obtain a third target light beam; the third target light beam and the second target light beam are controlled to be output from the third port of the quantum state probe regulation module; the third target light beam is used as a light source for Rabi probe, and the second target light beam is used as a light source for Ramsey probe.

[0025] The application discloses a clock laser regulation device compatible with Rabi probe and Ramsey probe. When Rabi probe and Ramsey probe act periodically on a group of atoms, the resonance frequency can be accurately locked by means of Rabi probe, and Dick effect noise can be effectively weakened by means of Ramsey probe, so that the technical advantages of the two probe methods are fully utilized, and the stability and measurement accuracy of the optical clock system are significantly improved.

[0026] In order for those skilled in the art to better understand the application, the technical solutions in the embodiments of the application will be described clearly and completely in conjunction with the drawings in the embodiments of the application. Obviously, the described embodiments are only part of the embodiments of the application, not all. Based on the embodiments in the application, all other embodiments obtained by those skilled in the art without creative labor are within the scope of protection of the application.

[0027] Figure 1 A structural schematic diagram of a clock laser regulation device provided by the embodiments of the application is shown. In combination with Figure 1 The clock laser regulation device 100 disclosed by the application comprises a clock laser source 1, a laser beam splitting module 2, a quantum state probe regulation module 3 and a phase elimination module 4.

[0028] The clock laser source 1 is connected with the first port of the laser beam splitting module 2; the second port of the laser beam splitting module 2 is connected with the first port 3011 of the quantum state exploration and regulation module 3; the third port of the laser beam splitting module 2 is connected with the first port 41 of the phase elimination module 4; the second port 42 of the phase elimination module 4 is connected with the second port 3062 of the quantum state exploration and regulation module 3.

[0029] The laser beam splitting module 2 is used for splitting the initial light beam output by the clock laser source 1 into a first initial light beam and a second initial light beam.

[0030] The phase elimination module 4 is used for phase locking the received second initial light beam to generate a reference light beam.

[0031] The quantum state exploration and regulation module 3 is used for generating a modulation light beam based on the first initial light beam and the reference light beam; performing time sequence regulation on the propagation direction of the modulation light beam to obtain alternately output first target light beam and second target light beam; attenuating the light intensity of the first target light beam to obtain a third target light beam; controlling the third target light beam and the second target light beam to be output from the fifth port 3035 of the quantum state exploration and regulation module 3; the third target light beam is used as a light source for Rabi exploration, and the second target light beam is used as a light source for Ramsey exploration.

[0032] Combining Figure 1 As shown in the figure, the quantum state exploration and regulation module 2 comprises a frequency shift modulation unit 301, a light beam switching unit 302, a light splitting and combining unit 303, an optical power detector 304, a PID servo control unit 305, a beat frequency detector 306 and a frequency division phase-locked servo control unit 307.

[0033] The first port 3011 of the frequency shift modulation unit 301 is the first port of the quantum state exploration and regulation module 3; the second port 3012 of the frequency shift modulation unit 301 is connected with the first port 3021 of the light beam switching unit 302; the second port 3022 of the light beam switching unit 302 is connected with the first port 3031 of the light splitting and combining unit 303; the third port 3023 of the light beam switching unit 302 is connected with the second port 3032 of the light splitting and combining unit 303;

[0034] The third port 3033 of the light splitting and combining unit 303 is connected with the first port 3041 of the optical power detector 304; the second port 3042 of the optical power detector 304 is connected with the first port 3051 of the PID servo control unit 305; the second port 3052 of the PID servo control unit 305 is connected with the third port 3013 of the frequency shift modulation unit 301;

[0035] The fourth port 3034 of the light splitting and combining unit 303 is connected with the first port 3061 of the beat frequency detector 306; the second port 3062 of the beat frequency detector 306 is the second port of the quantum state interrogation and control module 3; the third port 3063 of the beat frequency detector 306 is connected with the first port 3071 of the frequency division phase-locked servo control unit 307; and the second port 3072 of the frequency division phase-locked servo control unit 307 is connected with the fourth port 3014 of the frequency shift modulation unit 301.

[0036] The units in the quantum state interrogation and control module 3 are specifically used for:

[0037] The frequency shift modulation unit 301 is configured to modulate the first initial light beam according to the first control signal output by the PID servo control unit 305 and the second control signal output by the frequency division phase-locked servo control unit 307, to generate a modulated light beam.

[0038] The light beam switching unit 302 is configured to time-sequentially control the propagation direction of the modulated light beam, so that the modulated light beam is periodically switched between the double light paths to obtain the first target light beam and the second target light beam which are alternately output.

[0039] The light splitting and combining unit 303 is configured to attenuate the light intensity of the first target light beam to obtain a third target light beam; and control the third target light beam and the second target light beam to be output from the third port 3035 of the quantum state interrogation and control module 3.

[0040] The optical power detector 304 is configured to detect the second target light beam or the third target light beam to obtain a first detection signal.

[0041] The PID servo control unit 305 is configured to generate the first control signal based on the first detection signal.

[0042] The beat frequency detector 306 is configured to detect the second target light beam or the third target light beam to obtain a second detection signal; detect the reference light beam to obtain a third detection signal; and obtain a beat frequency signal based on the second detection signal and the third detection signal.

[0043] The frequency division phase-locked servo control unit 307 is configured to generate the second control signal based on the beat frequency signal.

[0044] The use process of the clock laser control device 100 is as follows:

[0045] A1, the clock laser source 1 is started to output an initial light beam.

[0046] A2, after the initial light beam enters the laser beam splitting module 2 through the first port 21 of the laser beam splitting module 2, the initial light beam is split into a first initial light beam and a second initial light beam inside the laser beam splitting module 2; the first initial light beam is transmitted from the second port 22 of the laser beam splitting module 2 to the first port 3011 of the frequency shift modulation unit 301; the second initial light beam is transmitted from the third port 23 of the laser beam splitting module 2 to the first port 41 of the phase cancellation module 4; after the phase cancellation module 4 phase-locks the received second initial light beam, the reference light beam is output from the second port 42 of the phase cancellation module 4.

[0047] Wherein, the laser beam splitting module 2 is composed of a wave plate and a polarization beam splitter; the first port 21 of the laser beam splitting module 2 corresponds to a spatial light path, the second port 22 of the laser beam splitting module 2 corresponds to a spatial light path or a fiber interface, and the third port 23 of the laser beam splitting module 2 corresponds to a spatial light path.

[0048] A3, the frequency shift modulation unit 301 modulates the first initial light beam to generate a modulated light beam after receiving the first initial light beam, the first control signal output by the PID servo control unit 305 (the first control signal is used for power modulation of the first initial signal) and the second control signal output by the frequency division phase-locked servo control unit 307 (the second control signal is used for frequency modulation of the first initial signal). Wherein, the modulated light beam is output from the second port 3012 of the frequency shift modulation unit 301.

[0049] Wherein, the frequency shift modulation unit 301 contains an acousto-optic modulator and a radio frequency driver; the first initial light beam input into the frequency shift modulation unit 301 is modulated by the acousto-optic modulator, and the first-order diffraction light is output from the second port 3012 of the frequency shift modulation unit 301; the second port 3012 of the frequency shift modulation unit 301 corresponds to a spatial light path or a fiber interface; the radio frequency power output by the radio frequency driver is controlled by the first control signal input from the third port 3013 of the frequency shift modulation unit 301; the radio frequency frequency output by the radio frequency driver is controlled by the second control signal input from the fourth port 3014 of the frequency shift modulation unit 301.

[0050] A4, after the modulated light beam output by the frequency modulation unit 301 enters the beam switching unit 302, the beam switching unit 302 controls the propagation direction of the modulated light beam in time sequence, so that the modulated light beam realizes periodic switching between the double light paths, and the first target light beam and the second target light beam output alternately are obtained; wherein, the first target light beam is output from the second port 3022 of the beam switching unit 303; the second target light beam is output from the third port 3023 of the beam switching unit 303; essentially, the first target light beam and the second target light beam are derived from the same modulated light beam; are two branches derived from the same modulated light beam after being conducted through different transmission paths; the core parameters of the first target light beam and the second target light beam, such as laser power and laser frequency, are exactly the same.

[0051] The light beam switching unit 302 can be a free-space double mechanical gate optical switch, a fiber-optic microelectromechanical optical switch, or a double acousto-optic modulator optical switch.

[0052] It can be understood that the light beam switching unit 302 does not output the first target light beam and the second target light beam at the same time, but outputs the first target light beam and the second target light beam in an alternating manner.

[0053] A5, the first target light beam output from the second port 3022 of the light beam switching unit 303 enters the inside of the light beam splitting and combining unit 303 through the first port 3031 of the light beam splitting and combining unit 303; the second target light beam output from the third port 3023 of the light beam switching unit 303 enters the inside of the light beam splitting and combining unit 303 through the second port 3032 of the light beam splitting and combining unit 303; the light beam splitting and combining unit 303 attenuates the intensity of the first target light beam to obtain a third target light beam; the light beam splitting and combining unit 303 controls the third target light beam or the second target light beam to be output outward from the third port 3033, the fourth port 3034, and the fifth port 3034 of the light beam splitting and combining unit 303; the fifth port of the light beam splitting and combining unit 303 is a third port of the quantum state interrogation and control module 3.

[0054] The advantage of controlling the third target light beam and the second target light beam to be output from the third port of the quantum state interrogation and control module 3 to act on the target detection substance (such as an atomic group) in the present application is that after the first initial light beam output by the clock laser source 1 enters the quantum control module 3, only one light transmission hole site facing the target detection substance needs to be opened on the quantum control module 3 to realize interrogation, reducing the complexity of the mechanical structure of the quantum control module 3.

[0055] It should be noted that the specific structure of the light beam splitting and combining unit 303 in the subsequent embodiments of the present application is not limited to the above. Figure 3 The specific structure of the light beam splitting and combining unit 303 will be described in detail.

[0056] A6, the light beam output from the third port 3033 of the light beam splitting and combining unit 303 is transmitted to the first port 3041 of the optical power detector 304, and the optical power detector 304 converts the detected light intensity into a first electric signal after detecting the light beam, and transmits the first electric signal outward from the second port 3042 of the optical power detector 304; at the same time, the light beam output from the fourth port 3034 of the light beam splitting and combining unit 303 is transmitted to the first port 3061 of the beat frequency detector 306, and the beat frequency detector 306 processes the light beam output by the light beam splitting and combining unit 303 and the reference light beam output by the phase module 4 to obtain a beat frequency signal.

[0057] The optical power detector 304 includes a photodiode, converts the laser power signal into a corresponding first electrical signal by using a photoelectric effect, and has a bandwidth greater than 100 kHz.

[0058] A7, the first electrical signal output from the second port 3042 of the optical power detector 304 enters the inside of the PID servo control unit 305 through the first port 3051 of the PID servo control unit 305, the PID servo control unit 305 performs a PID algorithm on the first electrical signal to generate a first control signal; the first control signal is transmitted out from the second port 3052 of the PID servo control unit 305 and enters the inside of the frequency shift modulation unit 301 through the third port 3013 of the frequency shift modulation unit 301; wherein the PID servo control unit 305 can be a digital PID board card or an analog PID board card, and has a bandwidth greater than 100 kHz, so as to realize laser power stabilization.

[0059] Meanwhile, the beat signal is output from the third port 3063 of the beat detector 306 to the first port 3071 of the frequency division phase-locked servo control unit 307, the frequency division phase-locked servo control unit 307 performs a servo operation on the beat signal to generate a second control signal; the second control signal is transmitted out from the second port 3072 of the frequency division phase-locked servo control unit 307 and enters the inside of the frequency shift modulation unit 301 through the fourth port 3014 of the frequency shift modulation unit 301.

[0060] The frequency division phase-locked servo control unit 307 is composed of a phase-locked board card with a frequency division function, and is used for phase locking the beat signal after frequency division with a reference signal. In the frequency division phase-locked servo control unit 307, the phase-locked board card is used for performing even-number frequency division on the beat signal.

[0061] In the present application, the reference light beam is represented as cos(ω0t), ω0 is the frequency of the reference light beam, and t is time; the clock laser injected onto the atomic group for interrogation is represented as cos[(ω0+ω d )t+θ(t)], wherein ω0 is the frequency of the reference light beam, ω d is the frequency shift frequency, and θ(t) is the phase noise of the link; the beat signal of the clock laser injected onto the atomic group for interrogation and the reference light beam is represented as the clock laser injected onto the atomic group for interrogation; the beat signal is subjected to N (N is an even number) times of frequency division by the phase-locked board card in the frequency division phase-locked servo control unit 307 to obtain an N-divided signal, which is represented as cos{[ω d t+θ(t)] / N}; the radio frequency reference signal is represented as cos(ω ref t), wherein ω ref is the frequency of the radio frequency reference signal; after the N-divided signal is locked to the radio frequency reference signal by the phase-locked board card, [ω d t+θ(t)] / N=ωref t+mπ, where m is an integer.

[0062] From the formula [ω d t+θ(t)] / N=ω ref From t+mπ, we know that when N is a positive odd number, and m jumps between odd and even numbers, the clock laser will exhibit a π-phase jump problem; since N is a positive even number, the clock laser is cos(ω0t+Nω ref The phase is stable, eliminating the π phase jump problem. This application uses a phase-locked loop (PLL) board in the frequency division phase-locked servo control unit 307 to perform positive even-number frequency division on the beat frequency signal, thus solving the problem of probe failure caused by phase jumps during Ramsey probing.

[0063] Upon receiving the first initial beam, the first control signal output by the PID servo control unit 305, and the second control signal output by the frequency division phase-locked servo control unit 307, the frequency shift modulation unit 301 can control the power and frequency of the first initial beam according to the contents recorded in A3-A7, to obtain a third target beam used as a light source for Rabi interrogation and a second target beam used as a light source for Ramsey interrogation; and cause the third target beam and the second target beam to alternately act on the target interrogation substance, such as atomic groups.

[0064] As can be seen from the description of the structure of the clock laser control device 100 and the description of its usage, the clock laser control device disclosed in this application is compatible with both Rabi and Ramsey probing methods; it solves the problem of phase transition of Ramsey probing pulses in existing optical clock systems and the problem that Ramsey probing is incompatible with Rabi probing optical schemes. At the same time, the clock laser control device 100 meets the miniaturization requirements of optical clock systems.

[0065] Figure 2 This is a schematic diagram of a beam-splitting unit provided in an embodiment of this application. Below, in conjunction with… Figure 2 Regarding this application Figure 1 The structure of the mid-splitter combination unit 303 is described in detail.

[0066] Combination Figure 2 As shown, incident on Figure 2 The propagation path of the first target beam in the beam splitting unit 303 is indicated by a green arrow, and the propagation path of the second target beam is indicated by a red arrow; the beam splitting unit 303 includes: a first branch optical path, a second branch optical path, a third branch optical path, and a fourth branch optical path.

[0067] The first branch light path comprises a first polarization beam splitter, a first non-polarization beam splitter, an attenuator, a first mirror and a second non-polarization beam splitter; the second branch light path comprises the first polarization beam splitter, the first non-polarization beam splitter, a second mirror and a third non-polarization beam splitter; the third branch light path comprises a second polarization beam splitter and the second non-polarization beam splitter; and the fourth branch light path comprises the second polarization beam splitter, the second non-polarization beam splitter and the third non-polarization beam splitter.

[0068] The first target light beam is transmitted along the first branch light path, sequentially passes through the first polarization beam splitter, the first non-polarization beam splitter, the attenuator, the first mirror and the second non-polarization beam splitter, and acts on the target probe substance. After passing through the attenuator, the first target light beam becomes a third target light beam with weakened light intensity, and the third target light beam is used as a light source for Rabi probe.

[0069] The first target light beam is transmitted along the second branch light path, sequentially passes through the first polarization beam splitter, the first non-polarization beam splitter, the second mirror and the third non-polarization beam splitter, and acts on the optical power detector and the beat frequency detector.

[0070] The second target light beam is transmitted along the third branch light path, sequentially passes through the second polarization beam splitter and the second non-polarization beam splitter, and acts on the target probe substance; the second target light beam is used as a light source for Ramsey probe.

[0071] The second target light beam is transmitted along the fourth branch light path, sequentially passes through the second polarization beam splitter, the second non-polarization beam splitter and the third non-polarization beam splitter, and acts on the optical power detector and the beat frequency detector.

[0072] Figure 3 A structural schematic diagram of a phase cancellation module is provided for the embodiments of the present application. Next, the structure of the phase cancellation module 4 in the embodiment shown in Figure 3 will be described in detail. Figure 1

[0073] Next, the structure of the phase cancellation module 4 in the embodiment shown in Figure 3 will be described in detail.

[0074] The first direction control unit is configured to control the propagation direction of the second initial light beam, so that the second initial light beam is transmitted to the phase locking unit.

[0075] The second direction control unit is configured to control the propagation direction of the second initial light beam carrying noise, so that the second initial light beam carrying noise is transmitted to the phase locking unit.

[0076] The phase locking unit is configured to generate a reference light beam based on the radio frequency reference signal, the second initial light beam and the second initial light beam carrying noise.​

[0077] The first direction control unit comprises a half wave plate, a third polarization beam splitter prism and a polarizer; the second initial light beam is transmitted to the phase locking unit in sequence through the half wave plate, the third polarization beam splitter prism and the polarizer.

[0078] The second direction control unit comprises a half wave plate, a third polarization beam splitter prism, an acousto-optic modulator, a first quarter wave plate, a half mirror, a second quarter wave plate, a full mirror and a polarizer. The second initial light beam is transmitted to the half mirror in sequence through the half wave plate, the third polarization beam splitter prism, the acousto-optic modulator and the first quarter wave plate; the transmission light beam of the second initial light beam that transmits through the half mirror is taken as the reference light beam, and the reflection light beam of the second initial light beam that is reflected by the half mirror is transmitted to the full mirror in sequence through the first quarter wave plate, the acousto-optic modulator, the third polarization beam splitter prism and the second quarter wave plate; the reflection light beam is reflected by the full mirror and is transmitted to the phase locking unit in sequence through the second quarter wave plate, the third polarization beam splitter prism and the polarizer.

[0079] The phase locking unit comprises a radio frequency reference source (outputting a radio frequency reference signal), a target beat frequency detector, a mixer, a PID board card and a radio frequency driver.

[0080] In combination Figure 3 As shown in the figure, the output port of the radio frequency reference source is connected with the first port m1 of the mixer, the output port of the target beat frequency detector is connected with the second port m2 of the mixer, the third port m3 of the mixer is connected with the first port d1 of the PID board card; the second port d2 of the PID board card is connected with the first port s1 of the radio frequency driver; the second port s2 of the radio frequency driver is connected with the acousto-optic modulator.

[0081] The target beat frequency detector is used for detecting the second initial light beam to obtain a first target detection signal; detecting the second initial light beam carrying noise to obtain a second target detection signal; transmitting the first target detection signal and the second target detection signal to the mixer, the mixer mixing the two signals to extract a beat error signal reflecting the noise; the PID board card calculates a control quantity according to the error signal and outputs an adjustment instruction; the radio frequency driver adjusts the frequency or amplitude of the high-frequency driving signal according to the adjustment instruction, and the acousto-optic modulator modulates the second initial light beam under the action of the driving signal to offset the influence of the noise; the modulated light beam is detected again to form a closed loop, and finally a stable reference light beam is output.

[0082] It should be noted that each of the embodiments in the present specification is described in a progressive manner, and the same or similar parts between the embodiments can be mutually referred to. Each of the embodiments focuses on the differences from other embodiments. In particular, the method embodiments are described more simply because they are basically similar to the method embodiments, and the relevant parts can be referred to the part of the method embodiments. The method embodiments described above are merely illustrative, and the units described as separate components can or can not be physically separated, and the components indicated as units can or can not be physical units, that is, they can be located in one place, or distributed on multiple network units. Part or all of the modules can be selected to achieve the purpose of the embodiments according to the actual needs. Those skilled in the art can understand and implement it without creative labor.

[0083] The above describes only one specific implementation of the present application, but the protection scope of the present application is not limited to this. Any skilled person in the art can easily think of changes or replacements within the technical range disclosed in the present application, which should be covered within the protection scope of the present application. Therefore, the protection scope of the present application should be subject to the protection scope of the claims.

Claims

1. A clock laser regulation device, characterized by, The clock laser control device comprises a clock laser source, a laser beam splitting module, a quantum state interrogation control module and a phase elimination module. The clock laser source is connected with a first port of the laser beam splitting module; a second port of the laser beam splitting module is connected with a first port of the quantum state interrogation control module; a third port of the laser beam splitting module is connected with a first port of the phase elimination module; a second port of the phase elimination module is connected with a second port of the quantum state interrogation control module. The laser beam splitting module is used for splitting an initial light beam output by the clock laser source into a first initial light beam and a second initial light beam. The phase elimination module is used for phase locking the received second initial light beam to generate a reference light beam. The quantum state interrogation control module is used for generating a modulated light beam based on the first initial light beam and the reference light beam; timing controlling a propagation direction of the modulated light beam to obtain alternately output first and second target light beams; attenuating light intensity of the first target light beam to obtain a third target light beam; controlling the third target light beam and the second target light beam to be output from a third port of the quantum state interrogation control module; the third target light beam is used as a light source for Rabi interrogation, and the second target light beam is used as a light source for Ramsey interrogation.

2. The clock laser regulation device of claim 1, wherein, The quantum state interrogation control module comprises a frequency shift modulation unit, a light beam switching unit, a light splitting and combining unit, an optical power detector, a PID servo control unit, a beat frequency detector and a frequency division phase-locked servo control unit. A first port of the frequency shift modulation unit is a first port of the quantum state interrogation control module; a second port of the frequency shift modulation unit is connected with a first port of the light beam switching unit; a second port of the light beam switching unit is connected with a first port of the light splitting and combining unit; a third port of the light beam switching unit is connected with a second port of the light splitting and combining unit. A third port of the light splitting and combining unit is connected with a first port of the optical power detector; a second port of the optical power detector is connected with a first port of the PID servo control unit; a second port of the PID servo control unit is connected with a third port of the frequency shift modulation unit. A fourth port of the light splitting and combining unit is connected with a first port of the beat frequency detector; a second port of the beat frequency detector is a second port of the quantum state interrogation control module; a third port of the beat frequency detector is connected with a first port of the frequency division phase-locked servo control unit; a second port of the frequency division phase-locked servo control unit is connected with a fourth port of the frequency shift modulation unit.

3. The clock laser regulation device of claim 2, wherein, The frequency shift modulation unit is used for modulating the first initial light beam according to a first control signal output by the PID servo control unit and a second control signal output by the frequency division phase-locked servo control unit to generate the modulated light beam. ​ The light beam switching unit is configured to time-control a propagation direction of the modulated light beam, so that the modulated light beam is periodically switched between the two light paths, and the first target light beam and the second target light beam are alternately output. The light splitting and combining unit is configured to attenuate an intensity of the first target light beam to obtain the third target light beam, and control the third target light beam and the second target light beam to be output from a third port of the quantum state interrogation control module. The optical power detector is configured to detect the second target light beam or the third target light beam to obtain a first detection signal. The PID servo control unit is configured to generate the first control signal based on the first detection signal. The beat frequency detector is configured to detect the second target light beam or the third target light beam to obtain a second detection signal, detect the reference light beam to obtain a third detection signal, and obtain a beat frequency signal based on the second detection signal and the third detection signal. The frequency division phase-locked servo control unit is configured to generate the second control signal based on the beat frequency signal.

4. The clock laser control device of claim 2, wherein, The light beam switching unit is a free-space type double mechanical gate optical switch, a fiber type micro-electromechanical optical switch, or a double acousto-optic modulator optical switch.

5. The clock laser control device of claim 2, wherein, The light splitting and combining unit includes a first branch light path, a second branch light path, a third branch light path, and a fourth branch light path. The first branch light path includes a first polarization splitting prism, a first non-polarization splitting prism, an attenuator, a first mirror, and a second non-polarization splitting prism. The second branch light path includes the first polarization splitting prism, the first non-polarization splitting prism, a second mirror, and a third non-polarization splitting prism. The third branch light path includes a second polarization splitting prism and the second non-polarization splitting prism. The fourth branch light path includes the second polarization splitting prism, the second non-polarization splitting prism, and the third non-polarization splitting prism. The first target light beam is transmitted along the first branch light path, sequentially passes through the first polarization splitting prism, the first non-polarization splitting prism, the attenuator, the first mirror, and the second non-polarization splitting prism, and acts on a target interrogation substance. The first target light beam is transmitted along the second branch light path, sequentially passes through the first polarization splitting prism, the first non-polarization splitting prism, the second mirror, and the third non-polarization splitting prism, and acts on the optical power detector and the beat frequency detector. The second target light beam is transmitted along the third branch light path, sequentially passes through the second polarization splitting prism and the second non-polarization splitting prism, and acts on the target interrogation substance. The second target light beam is transmitted along the fourth branch light path, sequentially passes through the second polarization splitting prism, the second non-polarization splitting prism, and the third non-polarization splitting prism, and acts on the optical power detector and the beat frequency detector.

6. The clock laser regulation device of claim 2, wherein, The phase-locked board in the frequency division phase-locked servo control unit is configured to perform even-number frequency division on the beat frequency signal.

7. The clock laser regulation device of claim 1, wherein, The phase elimination module includes a first direction control unit, a second direction control unit, and a phase locking unit. The first direction control unit is configured to control a propagation direction of the second initial light beam, so that the second initial light beam is transmitted to the phase locking unit. The second direction control unit is configured to control a propagation direction of the second initial light beam carrying noise, so that the second initial light beam carrying noise is transmitted to the phase locking unit. The phase locking unit is configured to generate the reference light beam based on a radio frequency reference signal, the second initial light beam and the second initial light beam carrying noise.

8. The clock laser control device of claim 7, wherein, The first direction control unit comprises a half-wave plate, a third polarization beam splitter prism and a polarizer. The second initial light beam is sequentially transmitted to the phase locking unit through the half-wave plate, the third polarization beam splitter prism and the polarizer.

9. The clock laser control device of claim 8, wherein, The second direction control unit comprises the half-wave plate, the third polarization beam splitter prism, an acousto-optic modulator, a first quarter-wave plate, a half-transmissive half-reflective mirror, a second quarter-wave plate, a full-reflective mirror and the polarizer. The second initial light beam is sequentially transmitted to the half-transmissive half-reflective mirror through the half-wave plate, the third polarization beam splitter prism, the acousto-optic modulator and the first quarter-wave plate. The transmitted light beam of the second initial light beam that transmits through the half-transmissive half-reflective mirror is taken as the reference light beam, and the reflected light beam of the second initial light beam that is reflected by the half-transmissive half-reflective mirror is sequentially transmitted to the full-reflective mirror through the first quarter-wave plate, the acousto-optic modulator, the third polarization beam splitter prism and the second quarter-wave plate. The reflected light beam is reflected by the full-reflective mirror and is sequentially transmitted to the phase locking unit through the second quarter-wave plate, the third polarization beam splitter prism and the polarizer.

10. The clock laser control device of claim 7, wherein, The phase locking unit comprises a radio frequency reference source, a target beat frequency detector, a mixer, a PID board card and a radio frequency driver. An output port of the radio frequency reference source is connected with a first port of the mixer, an output port of the target beat frequency detector is connected with a second port of the mixer, a third port of the mixer is connected with a first port of the PID board card, a second port of the PID board card is connected with a first port of the radio frequency driver, and a second port of the radio frequency driver is connected with the acousto-optic modulator. The target beat frequency detector is configured to detect the second initial light beam to obtain a first target detection signal, detect the second initial light beam carrying noise to obtain a second target detection signal, and transmit the first target detection signal and the second target detection signal to the mixer.

Images