55 results about "Optical clock" patented technology

The invention discloses a multichannel clock buffer test system and method, and relates to the technical field of semiconductor testing, and the method comprises the steps: calibrating the delay of an optical clock signal of each time-to-digital converter node to a preset precision threshold value; a standard clock signal is injected into the clock buffer input channel, and the clock buffer is driven to enter a working state; triggering a time-to-digital converter array by using the calibrated optical clock signal, collecting timestamp data of each output channel of a clock buffer, and generating an original time data set; inputting the original time data set into a double-mixing processor, and outputting a multi-channel skew parameter and a three-dimensional cloud picture; the multi-channel skew parameter is converted to a life indicator value for each output channel of the clock buffer based on the multi-channel skew parameter invoking a material model. According to the invention, the original time data set is subjected to two times of frequency mixing processing through the double frequency mixing processors, and phase detection and spectrum analysis are combined, so that high-precision extraction of the time deviation value of each output channel of the clock buffer is realized.

The invention provides a single-frequency laser system and an optical clock and optical tweezers comprising the single-frequency laser system, a first single-frequency laser of the single-frequency laser system is a single-frequency thulium-doped distributed feedback fiber laser, and the first single-frequency laser is used for outputting first single-frequency laser; the thulium-doped optical fiber amplification module is used for receiving the first single-frequency laser and amplifying the power of the first single-frequency laser to form first amplified laser; the second single-frequency laser is used for outputting second single-frequency laser; the erbium-doped fiber amplification module is used for receiving the second single-frequency laser and amplifying the power of the second single-frequency laser to form second amplified laser; the laser beam combining module is used for combining the first amplified laser and the second amplified laser to form combined laser; and the sum frequency module is used for performing sum frequency conversion on the combined laser to form output laser which is output outwards. When the single-frequency laser system is applied to the optical clock, the frequency stability and various performance indexes of the optical clock can be improved; when the method is applied to optical tweezers, the control performance of the optical tweezers on atoms can be improved.

The application relates to the technical field of atomic clocks, and provides a chip optical clock based on a modulation transfer spectrum principle and an implementation method thereof. The chip optical clock comprises: an on-chip narrow-line-width laser for emitting laser; a waveguide beam splitter for splitting the laser into two beams; one beam of laser is used for inputting into an electro-optic phase modulator, and the other beam of laser is used for inputting into a MEMS atomic cell; the electro-optic phase modulator is used for phase-modulating the one beam of laser and outputting pump light; the MEMS atomic cell is used for modulating and transferring the other beam of laser based on the pump light to obtain a probe spectrum; a photoelectric detector is used for converting the detected probe spectrum into an electric signal; a high-speed servo feedback control integrated circuit is used for converting the received electric signal into a feedback control signal, inputting the feedback control signal into a feedback control port of the on-chip narrow-line-width laser, realizing full-bandwidth locking, and outputting an optical clock signal. The above-designed chip optical clock has small integration difficulty and is easy to realize full-chip optical clock.

The invention relates to the technical field of optical frequency standards, in particular to an optical clock based on single laser cesium two-photon transition, which comprises a 822.46 nm adjustable linear polarization laser system, a stable optical path, a laser power stable loop, a circularly polarized light conversion optical path, a cesium two-photon transition physical system and a fluorescence detection servo control system. According to the invention, by utilizing the characteristics of cesium atom two-photon transition leading line traction and small linear Zeeman frequency shift, a 822.46 nm frequency-combining single-frequency laser is adopted to excite two-photon transition so as to reduce the complexity of an optical clock, and a light beam position stable light path and a laser power stable loop which take an acousto-optic modulator as a core are added; and the circular polarization laser is generated, so that the cesium atoms are subjected to 6S-8S ground state two-photon transition, the excitation efficiency is improved, and the stability index of the cesium atomic clock is improved.

The invention relates to the technical field of optical atomic clocks, and discloses a multi-mode magnetic field generation and regulation device and method for a strontium atom optical clock, and the device comprises a three-dimensional magnetic field coil, a magnetic field control system, and a magneto-optical trap. The three-dimensional magnetic field coil comprises an X-direction magnetic field coil, a Y-direction magnetic field coil and a Z-direction magnetic field coil; the X-direction magnetic field coil, the Y-direction magnetic field coil and the Z-direction magnetic field coil are mutually orthogonal and are respectively arranged along opposite positions to form a cubic framework, and the magneto-optical trap is positioned in the cubic framework; the magnetic field control system is electrically connected with the X-direction magnetic field coil, the Y-direction magnetic field coil and the Z-direction magnetic field coil. The technical problems that an existing strontium atom optical clock system is complex in structure and high in power consumption and thermal load, and time sequence characteristics used by a magnetic field in the operation process of the optical clock are not fully utilized are solved.

A system (30) for controlling, regulating or authenticating a timer comprises means (31) for measuring the frequency signal and / or rate of one or more timers based on a time reference provided by an optical atomic clock (10) comprising an atomic vapor chamber (1), the atomic vapor chamber (1) comprises a hermetically sealed enclosure (8) defining a volume containing a vapor of a reference atom (2), the hermetically sealed enclosure (8) comprising an optical inlet (3) allowing transmission of a probe beam adapted to excite an optical transition of the reference atom (2) and an optical outlet (4) allowing transmission of a fluorescence signal from the reference atom (2), the hermetically sealed housing (8) further comprises a wall (5) through which the fluorescent signal can penetrate, said wall (5) being coated on its outer side with a coating (6) which is reflective to the fluorescent signal.

The present invention discloses a highly charged Nickel ion optical clock and its implementation method. It uses Ni12+ ions as the clock's reference system, which provides superior anti-interference capabilities and measurement precision compared to conventional low-charge-state ion optical clocks. The Ni12+ ions possess two transition spectral lines at 498 nm and 511 nm that can serve as clock transitions. Utilizing both 498 nm and 511 nm lasers enables a single ion reference system to output two clock signals, allowing for mutual verification. Frequency calibration using these two laser frequencies facilitates the timely detection of operational issues through abrupt changes in their frequency ratio. This approach avoids the problem inherent in a single optical frequency clock, where losing synchronization with the time reference can result in immediately undetectable, erroneous clock signal outputs, thereby significantly enhancing the overall stability of the optical clock.

The invention provides a preparation method of an anti-aging optical resonant cavity, and relates to the field of optical instrument manufacturing and application. Comprising the steps of zero expansion point measurement, drift rate measurement, aging pretreatment, monitoring and compensation of the optical resonant cavity. The zero expansion point measurement and the drift distance measurement can be obtained by adopting different methods such as a reference cavity beat frequency method, an optical comb measurement method and an optical clock measurement method; the aging pretreatment comprises two modes of high-temperature accelerated aging and long-term stable storage, so that the performance of the material reaches a stable state; and monitoring and compensating, namely compensating the linear drift rate by measuring the frequency drift rate. The problem that the ULE glass is inevitably aged in long-term use is solved.

A system includes an optical transmitter configured to modulate a pulsed laser signal based on a plurality of data signals to form a plurality of modulated optical data signals, perform optical time division multiplexing of the plurality of modulated optical data signals to obtain a multiplexed optical data signal, and transmitting the multiplexed optical data signal together with an optical clock signal derived from the pulsed laser signal; and an optical receiver comprising a clock recovery branch configured to recover the optical clock signal to a plurality of phase shift recovered optical clock signals and a data branch having a plurality of saturable absorbers (SAs), each SA being in optical communication with one of the phase shift recovered optical clock signals, and configured to receive the multiplexed optical data signal and to transmit one of the plurality of modulated optical data signals according to the recovered optical clock signal.

The invention relates to the technical field of optical clock metering instruments, in particular to a microscopic particle mass measurement method and system based on an optical lattice clock, and the method comprises the steps: forming a one-dimensional horizontal shallow light lattice to constrain a to-be-measured microscopic particle based on an optical lattice clock platform; firstly, to-be-measured particles are subjected to laser cooling and then loaded to optical lattices, and the to-be-measured particles are prepared to a ground state single Zeeman sub-energy level through optical pumping. Then, modulating a beam of lattice light in the one-dimensional horizontal shallow light lattice to enable the lattice light to periodically shake; then, determining the line widths of clock transition spectral lines of the particles to be measured under different modulation amplitudes, and finding out the critical modulation amplitude corresponding to the minimum line width; and finally, according to the critical modulation amplitude and the lattice light wavelength, accurately deducing the absolute mass of the microscopic particles imprisoned by the light lattice.

The invention particularly relates to a method for improving the frequency measurement accuracy of an optical lattice clock in a microgravity environment, which comprises the following steps of: splitting two beams of lattice light through a lattice light laser, respectively splitting two beams of lattice light from each beam of lattice light, and forming two one-dimensional horizontal optical lattices by four beams of lattice light; wherein a certain distance exists between the beam waist positions of the two one-dimensional horizontal optical lattices in the vertical direction, the midpoint position of the two one-dimensional horizontal optical lattices is the position of a magnetic field zero point in the magneto-optical trap, the projections of the axial directions of the two horizontal optical lattices in the vertical plane are parallel to each other, and the projections of the axial directions of the two horizontal optical lattices in the horizontal plane are perpendicular to each other; an acousto-optic modulator with identical parameters is loaded on a light path of each beam of lattice light and is used for linear frequency shift and modulation of lattice light frequency; two beams of clock laser are split by a clock laser light source to respectively excite different atomic groups in two one-dimensional horizontal optical lattices. Differential comparison of transition frequencies of different atomic group clocks is realized by synchronously detecting transition spectrum lines of different atomic group clocks, so that common-mode noise in an optical clock system is suppressed. According to the method, the optical lattice clock with ultra-high frequency measurement precision in a microgravity environment can be realized.

This application provides a continuous cold atom optical clock based on optical clusters, relating to the fields of cold atom technology and atomic clocks. It includes a first laser, a second laser, a first acousto-optic modulator, a second acousto-optic modulator, a third acousto-optic modulator, a first polarizer, a first polarizing beam splitter, a vacuum chamber, an electro-optic modulator, a detector, and a servo feedback circuit. By combining cold atom optical cluster technology with an atomic clock, a cold atom optical clock based on cold atom optical clusters is constructed. By maintaining the continuous action of the probe light, while the atoms are continuously cooled, the probe light can continuously act on the cold atom optical clusters, thereby obtaining continuous and stable clock transition spectra, realizing a continuous optical clock based on cold atom optical clusters, and obtaining continuous atomic clock transition signals. Furthermore, the probe light used to detect the atomic clock transition spectra and the re-pump light used to cool the atoms are provided by the same laser, which simplifies the optical clock structure.

The invention provides a chip optical clock temperature self-adaptive dynamic compensation method, which comprises the following steps of: establishing a temperature working point data framework through a brief data corresponding relation between a chip optical clock temperature working point and frequency stability; a distributed temperature sensor network is established to sense the multi-dimensional temperature of the environment; constructing a dynamic compensation model based on a temperature working point data framework and environment multi-dimensional temperature sensing; based on a correction strategy in dynamic compensation model construction, a corresponding compensation algorithm is designed, and by means of the method, adaptive solving of the optimal temperature working point of the chip optical clock and dynamic compensation of temperature fluctuation are achieved, the working performance directly related to the temperature is improved, and the method is easy to implement, reasonable and easy to operate.

Optoelectronic device with at least two optoelectronic circuits (2, 4a, 4b) for transmitting an optical clock signal to an electronic component (40-47, 74a, 74b), a control device (78a, 78b) for controlling the propagation times of the optoelectronic circuits and at least two electronic components (40-47, 74a, 74b), each of the at least two optoelectronic circuits (2, 4a, 4b) with: - a clock generation device (25) for generating the optical clock signal, - a converter element (30-37, 73a, 73b) for converting the optical clock signal into an electrical clock signal supplied to the electronic component (40-47, 74a, 74b), and - an optical line (60, 72a, 72b) from the clock generation device (25) to the converter element (30-37, 73a, 73b), wherein the optoelectronic circuit (2, 4a, 4b) has an adjustable optical element (60, 72a, 72b) for setting a propagation delay between the clock generating device (25) and the electronic component (40-47, 74a, 74b), where the optical line (60, 72a, 72b) is the adjustable optical element (60, 72a, 72b), wherein the transit time is adjustable by changing an optical length of the optical line (60, 72a, 72b), wherein the optical line (60, 72a, 72b) has a plurality of heating elements (61, 79a, 79b) for heating the optical line (60, 72a, 72b), wherein the optical length of the optical line (60, 72a, 72b) is adjustable for setting the transit time by heating the optical line (60, 72a, 72b), and wherein the control device (78a, 78b) is configured to individually control the individual heating elements (61, 79a, 79b) to generate a temperature gradient in order to compensate for a temperature gradient (62) within the optoelectronic device by means of this temperature gradient generated as a counter-gradient.

Parallel optical communication system technology has had a problem in which group delay time periods generally differ between wavelength channels and between spatial channels, and reception times of optical clock signals and optical main signals deviate from one another. An optical communication system according to the present invention is provided with a transmission device 100 for transmitting, through an optical transmission line 50, multiplexed signal light L mux obtained by subjecting an optical main signal Ssig, which has been modulated using transmission data on a signal multiplex axis 1, to clock modulation in which the optical main signal is further modulated by a clock signal Sclk on a signal multiplex axis 2 orthogonal to the signal multiplex axis 1. A reception device 200 acquires transmission data (main signal) by sampling the multiplexed signal light, which has propagated through the optical transmission line 50, on the basis of the modulation method of the clock modulation.

This invention discloses a method for determining the lunar orbit expansion rate using a lunar optical clock, comprising: acquiring the relative frequency deviation between a ground optical clock and a lunar optical clock obtained through continuous measurement via a two-way Earth-Moon time-frequency transfer link; the two-way Earth-Moon time-frequency transfer link is established between a lunar surface station and a ground station for realizing optical clock time-frequency signal comparison and laser ranging, wherein both the lunar surface station and the ground station are equipped with a frequency deviation better than 10. ‑20 This invention utilizes an optical clock of magnitude [missing information]; based on the gravitational redshift theory of general relativity, a physical relationship model is established between the rate of change of relative frequency deviation and the lunar orbit expansion rate; based on this physical relationship model, the lunar orbit expansion rate is calculated from the measured rate of change of relative frequency deviation. This invention achieves direct, continuous, and high-precision measurement of lunar orbit expansion, overcoming the limitations of traditional lunar laser ranging technology, and providing a new generation of measurement methods for the study of Earth-Moon system dynamics and fundamental physics verification.

This invention provides a thorium-doped fluoride crystal, its preparation method, and a solid-state nuclear optical clock using the thorium-doped fluoride. The thorium-doped fluoride crystal uses SrF2, LiF, BaF2, and LiF+BaF2 as matrix materials, respectively, and ThF4 as a dopant material. Single crystals of Th:SrF2, Th:LiF, Th:BaF2, and Th:BaLiF3 are obtained through a melt growth process according to a pre-set molar percentage of the raw materials. The thorium-doped fluoride crystal of this invention has a low melting point and simple composition, which is beneficial for achieving high-quality crystal growth. It has an extremely wide band gap, high transmittance in the vacuum ultraviolet band, and a high Th doping concentration, which helps reduce absorption loss and background luminescence in the nuclear transition emission band, and is beneficial for the excitation and detection of nuclear transition signals. It can be used as a preferred material for applications based on… 229 A solid-state nuclear optical clock based on the transition of the Th atom nucleus.

What is needed is an optical scheme that provides high collection efficiency while reducing the effects of the vapor cell heating the temperature-sensitive photodetector.SOLUTION: The system for controlling, adjusting or certifying the timepiece includes a means for measuring a frequency signal and / or a rate of the timepiece or several timepieces based on a time reference provided by an optical electronic timepiece 10. Wherein the optical electronic watch comprises an atomic vapor cell 1, the atomic vapor cell comprising a sealed enclosure defining a volume containing a reference atomic vapor, the sealed enclosure comprising an optical inlet 3 allowing transmission of a probe beam adapted to excite an optical transition of the reference atoms and an optical outlet 4 allowing transmission of a fluorescence signal from the reference atoms, the sealed enclosure further comprising a wall 5 transparent to the fluorescence signal and coated on its outside with a coating reflecting the fluorescence signal.SELECTED DRAWING: Figure 5

The application provides an earth gravity field inversion method in an inter-satellite tracking mode based on an optical clock, comprising: using a numerical simulation method, the accuracy of the inversion of the earth gravity field in the inter-satellite tracking mode of the satellite-borne optical clock satellite is systematically evaluated. The simulator generates simulated observation data as input in the orbit of the gravity satellite (such as the GOCE and GRACE orbits), and estimates the gravity field coefficients by using a strict least square method. The accuracy of the results is evaluated by comparing the coefficient difference between the inversion model and the reference model. The application evaluates the accuracy of the inversion of the earth gravity field in the inter-satellite tracking mode based on the optical clock through the numerical simulation method, and verifies the potential of the optical clock in the high-precision gravity field measurement. In the future research, the optical clock noise model and the multi-sensor fusion method will be further optimized to improve the inversion accuracy of the high-order gravity field, and more accurate data support will be provided for the earth science and global climate change research.

The invention discloses an optical frequency signal interstellar gravitational potential difference measurement method, which comprises the following steps of: respectively establishing an optical clock optical frequency comparison system on two planets of which the gravitational potential difference needs to be measured so as to construct a planet-planet three-frequency combined optical frequency comparison link; according to the constructed planet-planet three-frequency combination optical frequency comparison link, bidirectional optical frequency signals are transmitted, received and reflected between the two planets, and the transmitting frequency f1, the reflecting frequency and the receiving frequency of the link from the first planet to the second planet to the first planet and the transmitting frequency f2 and the receiving frequency of the link are recorded respectively; according to an interstellar unidirectional frequency transfer model, in combination with each recorded frequency, extracting a gravitational red shift frequency shift between the two planets; and according to the relationship between the gravitational red shift frequency shift and the gravitational potential difference, the gravitational potential difference between the two planets is calculated.

The application discloses a laser system and a laser generation method applied to a strontium atomic optical clock, and the laser system comprises a plurality of seed lasers, a fiber amplifier, a fiber combiner, a fiber splitter and a nonlinear crystal, wherein the laser output by the second and third outputs of the seed lasers is combined, and after frequency conversion, 813nm laser is output; the laser output by the first output of the seed lasers is combined with the above-mentioned 813nm laser, and after frequency conversion, 461nm laser is output; the laser output by the fourth output of the seed lasers is divided into four beams, one of which is combined with the 813nm laser, after difference frequency conversion, 1397nm laser is output, and after frequency doubling, 698nm laser is output; the other three beams are combined with the laser output by the fifth, sixth and seventh outputs of the seed lasers respectively, and after frequency conversion, 679nm, 689nm and 707nm laser is output respectively. Seven special wavelength fiber seed lights are used in the application, and through the fiber amplifier and nonlinear frequency conversion, various wavelengths of laser required in the operation process of the strontium atomic optical clock are formed.

This invention discloses a stabilized optical clock system and its implementation method based on a dual-microcavity optical comb and two-photon transitions. The system includes a microcavity optical comb section, a locking section, and a photodetector. The microcavity optical comb section contains two SiO2 microchip ring cavity optical comb oscillators, with center wavelengths matched to the two-photon transition lines of rubidium and cesium atoms, respectively. The locking section provides an atomic reference frequency through a two-photon transition generator, and combines a six-way phase-locked loop, an acousto-optic modulator, and a phase modulator to achieve initial frequency locking of the optical comb, interlocking of the repetition frequency, and suppression of thermally induced detuning. The photodetector converts the stabilized optical comb repetition frequency into an RF frequency standard output. This invention solves the problems of complex system design, large integrated size, cumbersome locking structure, and wavelength mismatch in existing ultra-high frequency stabilized atomic clock technologies.

The application relates to a method for improving the frequency measurement precision of an optical lattice clock in a microgravity environment, which comprises the following steps: two beams of lattice light are divided from one lattice light laser, each beam of lattice light is further divided into two beams of lattice light, and four beams of lattice light form two one-dimensional horizontal optical lattices; wherein the waist positions of the two one-dimensional horizontal optical lattices have a certain interval in the vertical direction, and the midpoint position is the position of the magnetic field zero point in the magneto-optical trap; the projections of the axial directions of the two horizontal optical lattices in the vertical plane are parallel to each other, and the projections in the horizontal plane are perpendicular to each other; an acousto-optic modulator with the same parameters is loaded on the light path of each beam of lattice light, and is used for linear frequency shift and modulation of the lattice light frequency; two clock laser beams are divided from one clock laser source, and are used for exciting different atomic groups in the two one-dimensional horizontal optical lattices. By synchronously detecting the clock transition spectral lines of each different atomic group, the differential comparison of the clock transition frequencies of different atomic groups is realized, so that the common-mode noise in the optical clock system is suppressed. The method can realize an optical lattice clock with super-high frequency measurement precision in a microgravity environment.

The present invention belongs to the field of laser technology, and specifically relates to an intelligent adaptive control and self-feedback stabilization system for a microcavity soliton optical frequency comb. The present invention adopts an auxiliary photothermal tuning scheme, combined with an FPGA chip to monitor and control the parameters of each device in the system. By analyzing the power curves of each state in the soliton optical frequency comb generation process, different adaptive tuning strategies are designed for it, and a complete closed-loop feedback tuning link is constructed, realizing the lumped excitation, parallel control, and collaborative feedback technology of the on-chip soliton optical frequency comb generation system. The overall system parameter indicators are excellent, the soliton excitation time is less than 60s, the soliton stable existence time is greater than 24h, and the overall system volume is only 30×20×15cm 3 , which greatly improves the ease of use, practicality and portability of frequency comb light sources, promotes the formation of new electro-optical hybrid integrated frequency comb signal source devices and systems, and serves new applications of ultra-stable optical clocks, ultra-fast optical communications, and ultra-sensitive optical sensors.

The present application relates to the technical field of optical atomic clock, and discloses a kind of for strontium atom optical clock Multi-mode magnetic field generation and regulation device and method, including three-dimensional magnetic field coil, magnetic field control system and magneto-optical trap;Three-dimensional magnetic field coil includes X direction magnetic field coil, Y direction magnetic field coil and Z direction magnetic field coil;X direction magnetic field coil, Y direction magnetic field coil and Z direction magnetic field coil mutually orthogonal and respectively along opposite position arrangement form cubic skeleton, and magneto-optical trap is located in cubic skeleton;Magnetic field control system is respectively with X direction magnetic field coil, Y direction magnetic field coil and Z direction magnetic field coil electric connection setting.The present application solves the technical problem that the existing strontium atom optical clock system structure is complex, power consumption and thermal load is higher, and not fully utilize the time sequence characteristics of magnetic field use in the process of optical clock operation.

The embodiment of the invention provides a miniature modulation transfer spectrum rubidium atom optical clock based on a light building block structure and an implementation method thereof, and the implementation method comprises the steps: a thumb laser emits narrow linewidth laser, after light spots are expanded through a beam expander, a first half-wave plate and a first polarization splitting prism are matched to adjust the light splitting power, the narrow linewidth laser is divided into two beams, and one beam is used for a laser frequency stabilization light path; one beam used for a laser frequency stabilization light path is divided into two beams with different light intensities by a second half-wave plate and a second polarization splitting prism, and the two beams comprise pump light and probe light; the pump light enters rubidium atoms in the double-layer miniature rubidium atom gas chamber to interact after being subjected to phase modulation by the electro-optical modulator, and the probe light is detected and received by the high-speed photoelectric detector after interacting with the rubidium atoms in the double-layer miniature rubidium atom gas chamber and is converted into an electric signal; the mixer generates an error signal according to the electric signal and the demodulation signal, and the servo feedback control circuit controls the laser driving power supply according to the error signal, thereby achieving the output of high-stability narrow-linewidth laser, and achieving the effect of reducing the overall size.

The application discloses a clock synchronization system and a computer cluster, and relates to the technical field of servers.The clock synchronization system comprises an optical clock signal source, a fiber transmission assembly, a clock signal receiving assembly and a clock signal synchronization assembly.The clock signal receiving assembly is connected with the clock signal synchronization assembly, and the clock signal receiving assembly is further connected with the optical clock signal source through the fiber transmission assembly.The optical clock signal source is used for generating an initial clock signal and sending the initial clock signal to the clock signal interface assembly through the fiber transmission assembly.The initial clock signal is an optical signal.The clock signal receiving assembly is used for converting the initial clock signal into a target clock signal.The target clock signal is an electrical signal.The clock signal synchronization assembly is used for performing clock synchronization according to the target clock signal.In the clock synchronization system, clock synchronization can be performed based on an optical signal, and the clock signal can be transmitted through an optical fiber.The clock synchronization system improves the precision of clock synchronization.

The application discloses a chip active optical clock based on grating magneto-optical trap cooling and an implementation method thereof. Three saturated absorption spectrum frequency stabilization DBR lasers are used to generate cooling laser, re-pumping laser and pumping laser respectively, wherein the cooling laser and the re-pumping laser cooperate with the grating magneto-optical trap, are used for cooling and confining atoms, and form a cold atom group in an atom chamber; the pumping laser excites the cold atoms, and the generated stimulated radiation signal is directly used as an optical frequency standard signal output, and after frequency beating with a microcavity optical comb, a chip active optical clock is realized. Compared with a traditional cold atom optical clock, the application greatly reduces the volume of the system, can be integrated on a chip, and is suitable for a compact and portable device application scene; compared with a current chip microwave atomic clock, the stability index of the application is higher. The application has important application value, and can provide a long-time and high-precision frequency reference for a movable device.

This invention discloses a method and system for determining gravitational potential using a star-space-ground optical clock time-frequency comparison system. The method for determining gravitational potential proposed in this invention uses a time-frequency comparison system with a frequency better than 110... ‑18 Using a high-precision optical clock as the foundation, and a free-space time-frequency comparison link based on optical frequency combs as the bridge, the optical clocks between space, air and ground are connected to achieve high-precision time-frequency transmission. By comparing the time and frequency of the remote clock, the gravity frequency shift signal is accurately extracted. Then, the gravity frequency shift equation is used to obtain the gravity potential difference at the location of the remote clock, and the gravity potential difference between the air and the ground or between any ground station is determined.