97 results about "Optical frequencies" patented technology

The invention relates to the technical field of optical fiber frequency transmission, in particular to a distributed optical fiber optical frequency transmission method and system.The distributed optical fiber optical frequency transmission system is composed of a sending end and a plurality of receiving ends which are connected through an optical fiber link. An optical signal transmission module of a sending end divides laser generated by a laser into reference light and modulated light, the modulated light is transmitted to a receiving end after being subjected to positive frequency shift and wavelength division multiplexing, and return light is received at the same time. The signal processing module performs beat frequency processing on the reference light and the return light to obtain a radio frequency signal, performs phase processing to obtain an instantaneous frequency value, and modulates and converts the instantaneous frequency value into an optical signal through the optical transmitter. And the optical modulator module at the receiving end demodulates the modulated optical signal to obtain an instantaneous frequency value, and drives the modulator at the receiving end by using the frequency value to obtain a final optical frequency signal. According to the system, distributed high-precision optical frequency transmission is realized.

A centimeter-resolution integrated photonic millimeter-wave (mmWave) radar chip operating in the mmWave V band based on a 4-inch wafer-scale thin-film lithium niobate (TFLN) technology is provided. The fabricated TFLN photonic mmWave integrated circuit has a first electro-optic modulator (EOM) capable of generating a broadband linear frequency modulated mmWave radar waveform through optical frequency multiplication of a low-frequency input signal, and a second EOM for frequency de-chirp of the reflected echo wave, thereby greatly relieving bandwidth requirements for the digital-to-analog converter in the transmitter and analog-to-digital converter in the receiver. In the absence of optical and electrical filters, the radar chip features continuous on-demand tunability of the center frequency and bandwidth, currently only limited by the bandwidths of electrical amplifiers. The radar chip provides a promising way to achieve high resolution sensing and detection for vehicle radar, airborne radar, and smart home in the 6G era.

The invention relates to an integrated microcavity optical comb repetition frequency and optical frequency locking device and method, and belongs to the technical field of integrated microcavity optical combs. The locking device comprises a pumping module, a power amplification module, a phase modulation module, an electro-optic driving module, an acousto-optic modulation module, an acousto-optic driving module, a band-pass filtering module, a micro-ring resonant cavity and a beam splitting module; the device comprises a soliton detection module, a control module, a repetition frequency detection module, a first feedback control module, an acetylene frequency stabilized laser, a beat frequency module, an optical frequency beat frequency detection module and a second feedback control module. The locking device can achieve full frequency locking of the microcavity optical comb, has the advantages of being high in frequency stability, wide in servo bandwidth, simple and compact in structure, tight in locking, low in noise, high in reliability and low in cost, and can provide a powerful tool for the field of precision measurement.

The present disclosure aims to reduce a strain of an observed waveform caused by a difference in proportional constant between responses of different optical frequencies of probe light resulting from vibration in a phase OTDR that uses different optical frequencies.In order to achieve the above-described objective, the present disclosure relates to, in vibration measurement using a phase OTDR, including a compensation optical pulse with a predetermined compensation optical frequency different from an optical frequency in an optical pulse pair composed of optical pulses with different optical frequencies and making the optical pulse pair incident on a sensing fiber, calculating a phase value of the optical pulse pair based on a signal of the optical frequency from a scattered light signal based on the optical pulse pair and calculating a phase value of the compensation optical frequency based on a signal of the compensation optical frequency, plotting the phase values calculated from the scattered light signal on a two-dimensional, for each optical pulse pair plane, having the phase value of the compensation optical frequency represented by a horizontal axis and the phase value of the optical pulse pair represented by a vertical axis, obtaining a gradient and a vertical axis intercept of the approximate straight line calculated from the plotted data, and correcting the phase value of the optical pulse pair using the gradient and the vertical axis intercept.

The invention discloses a noise suppression parameter self-adjusting optical fiber optical frequency transfer relay system, which comprises multiple stages of relay stations which are cascaded in sequence, each stage of relay station comprises a receiving end, an optical amplification end and a transmitting end which are connected in sequence, and the transmitting end of the previous stage of relay station is connected to the receiving end of the next stage of relay station, the receiving end is used for receiving an optical frequency signal from an upper-level relay station; the optical amplification end is used for carrying out coherent amplification on a received optical frequency signal, and the sending end is used for transmitting the optical frequency signal after coherent amplification to a next-stage relay station and measuring and eliminating additional phase noise in a signal transmission link. According to the optical fiber optical frequency transfer relay system, self-adjustment of noise suppression parameters can be effectively achieved, and therefore effective suppression of additional phase noise is achieved.

The invention relates to a formamidine thiosulfate second-order nonlinear optical crystal and preparation and application thereof, the chemical formula of the crystal material is [CH (NH2) 2] 2SO3S, the molecular weight is 203.27, the crystal material belongs to an orthorhombic crystal system, the space group is P212121, the unit cell parameter is # imgabs 0 # alpha = beta = gamma = 90 degrees, Z = 4, and the unit cell volume is # imgabs 1 #. Under 1064nm laser irradiation, the frequency doubling intensity of the powder is about two times that of monopotassium phosphate crystals, and phase matching can be realized. In addition, the crystal material has a wide light transmission wave band, the ultraviolet absorption cut-off edge is 253 nm, the optical band gap is 4.90 eV, and the crystal material is easy to grow. The wavelength range of the coherent light source can be expanded by using optical frequency conversion technologies such as second harmonic generation and optical parametric amplification. Therefore, the crystal material has important application value in the fields of laser frequency conversion, photoelectric information storage and the like.

The invention discloses an epoxy resin aging diagnosis method based on electric frequency and optical frequency combined characteristics, and belongs to the technical field of electrical equipment insulation aging assessment. The sum of products of frequency under electric frequency and a dielectric loss angle tangent value and the sum of products of frequency under optical frequency and the dielectric loss angle tangent value are used as characteristic values; the method comprises the following steps: fitting with equivalent breakdown field strength, constructing a quantitative characterization relationship between the equivalent breakdown field strength of an epoxy resin sample and an electric frequency-optical frequency dielectric loss angle tangent value, and evaluating the actual aging degree of the epoxy resin insulating material by calculating the decline rate of the equivalent breakdown field strength, thereby avoiding a large number of repeated breakdown experiments. The aging degree of the epoxy resin insulating material can be accurately and quickly evaluated; the function relationship between the breakdown field strength of the epoxy resin material and the electric frequency-optical frequency dielectric parameters is constructed from two directions, the evaluation index suitable for the aging degree of the whole period is established, and theoretical support is provided for accurate and rapid evaluation of the aging degree of the epoxy resin insulating material.

The invention relates to the technical field of optical fiber communication, and discloses an optical fiber optical frequency relay transmission system and method without a phase-locked loop. The optical fiber optical frequency relay transmission system comprises multiple stages of relay stations which are sequentially cascaded through an optical fiber transmission link, and for each stage of relay station, a first photoelectric detector is used for carrying out beat frequency processing on a current-stage optical frequency signal sent by a current-stage regeneration cavity-stabilized laser and an optical frequency signal received from a previous-stage relay station; frequency mixing and summation are carried out on the current-level beat frequency signal and an optical frequency signal transmitted by an upper-level relay station through the data interaction unit, so that noise accumulation generated in a signal transmission process in a traditional phase-locked loop scheme can be thoroughly eliminated; therefore, the noise item in the optical frequency signal output to the user side is completely counteracted, that is, the high-precision original optical frequency signal is provided for the user side, and long-distance and high-precision optical frequency transmission can be realized on the basis of reducing the complexity of system design.

The invention discloses an optical fiber optical frequency transmission relay system and method based on a spread spectrum technology. The relay system comprises a receiving module, a regenerative laser module and a sending module. The receiving module is used for demodulating the spread spectrum optical signal according to the second pseudo-random sequence to obtain a demodulated optical signal; the spread spectrum optical signal is a signal which is transmitted through an optical fiber link after a preceding stage performs spectrum spreading on the optical signal; the regeneration laser module is used for locking the frequency of the demodulation optical signal to generate a regeneration optical signal and splitting the regeneration optical signal to obtain a return optical signal and a transmission optical signal; the receiving module is also used for modulating the returned optical signal according to the second pseudo-random sequence and transmitting the modulated returned optical signal back to the preceding stage; and the sending module is used for demodulating the post-stage modulation return optical signal to obtain a demodulated return optical signal, carrying out noise suppression and spectrum spreading on the transmission optical signal according to the demodulated return optical signal and a third pseudo-random sequence, and then transmitting the transmission optical signal to the post-stage. By introducing the spread spectrum technology, the second-order Rayleigh scattering signals are filtered out, and the stability and reliability of the system are remarkably improved.

The present invention supplies a reference frequency to time reference devices (ePRTC) in remote locations via an optical network 30, said reference frequency being necessary in order to satisfy a holdover standard. There is no need to prepare a plurality of reference frequency-generating high-accuracy frequency reference devices or the like for each location of the time reference devices. In a transmission-side node N1, an optical frequency comb 12 is used to generate an optical signal SG2 in which deterioration of frequency accuracy has been suppressed by synchronizing with a reference frequency signal SG1 and which has been converted to a communication wavelength band, and the optical signal SG2 is sent to the optical network 30 via an optical frequency repeater 13. In a reception-side node N2, an optical signal SG4 received from the optical network 30 is inputted to an optical frequency comb 17 via an optical frequency repeater 16, and a frequency signal that has been synchronized with the received signal is generated. A time reference device 18 uses the frequency of a signal SG6 outputted by the optical frequency comb 17 to achieve time holdover at an accuracy that is within the standard. The optical frequency repeaters 13, 16 eliminate the influence of fiber noise.

A method for coherent optical transmission and reception and an apparatus thereof are proposed. The method for operating the apparatus for the coherent optical transmission and reception includes controlling output optical frequencies with a first frequency and a second frequency, generating analog signals respectively corresponding to the first frequency and the second frequency, obtaining beating signals for the analog signals, generating signal diagrams of relationships between a first signal and a second signal on the basis of the beating signals, determining phase differences between the first signal and the second signal on the basis of the signal diagrams, and determining skew values for the first signal and the second signal on the basis of the phase differences.

The invention provides a terahertz frequency comb generation verification method and system based on an optical fiber microcavity optical frequency comb, and the method comprises the steps: injecting a continuous wave laser into an optical fiber microcavity resonator to generate a stable Kerr optical frequency comb, enabling the Kerr optical frequency comb to work in a single soliton state or a soliton crystal state, and obtaining an optical frequency reference with low phase noise. Furthermore, spectrum selection is performed on the optical frequency comb, multiple groups of optical comb tooth pairs comprising comb teeth of different orders are actively selected, and the optical frequency difference of each group of comb tooth pairs is directly converted into an electric signal in a terahertz frequency band by utilizing a beat frequency effect of a photoelectric detector. A plurality of terahertz electric signals generated by different comb tooth pairs are integrated to form a multi-channel terahertz frequency comb. The method allows a plurality of discrete and frequency-controllable terahertz signal channels to be generated in parallel on a single optical platform through one-time optical processing and photoelectric conversion, so that multichannel terahertz frequency comb generation is realized.

The invention discloses a coherent optical frequency signal regeneration amplification system based on optical fiber transmission. The coherent optical frequency signal regeneration amplification system comprises a local narrow linewidth laser which outputs narrow linewidth laser; the first optical fiber coupler couples the narrow linewidth laser to the first acoustic optical modulator and the second acoustic optical modulator respectively; the output of the first acousto-optic modulator and superior transmission light are jointly coupled into a photoelectric detector by a second optical fiber coupler to generate a beat frequency signal; the signal processing module samples the beat frequency signal after conditioning the beat frequency signal, performs phase discrimination on the sampled signal and the digital reference signal to generate an error signal, and generates a first feedback signal and a second feedback signal according to the error signal to be respectively used by the local narrow linewidth laser and the first acousto-optic modulator; performing real-time cycle slip detection on the error signal and repairing a phase abnormal point to generate a third feedback signal to be used by a second acousto-optic modulator; and the second acousto-optic modulator outputs amplified regenerated laser. According to the invention, high-precision optical frequency signal transmission can be realized in a complex and changeable optical fiber environment with large noise.

The embodiment of the application provides a kind of arrayed microcavity blood pressure detection system based on digital light frequency double comb, it is related to optical sensing technical field.The input end of light intensity modulator is connected with laser, waveform generator respectively, the output end of light intensity modulator, polarization controller, on-chip optical microcavity array are sequentially connected;Light intensity modulator is modulated based on electrical modulation signal to single-frequency light, and optical frequency double comb signal is obtained;Optical frequency double comb signal enters on-chip optical microcavity array after polarization controller, on-chip optical microcavity array is pasted to the position of the artery to be measured, and on-chip optical microcavity array includes multiple sensing units, each sensing unit generates an independent pulse signal, and on-chip optical microcavity array obtains sensing signal based on optical frequency double comb signal and the jump extrusion of the artery to be measured position, and signal processing mechanism obtains blood pressure value information based on sensing signal.The detection system can realize the technical effect of improving the accuracy and convenience of blood pressure measurement.

Improved distributed acoustic detection array (DAS array) with optical fiber, the system comprising: an optical fiber a light transmitting and receiving arrangement in optical communication with the optical fiber; a circulating optical fiber loop containing a gate-controlled acousto-optic modulator (AOM), wherein the circulating optical fiber loop is connected to the optical fiber; wherein the DAS arrangement is characterized by: a bandpass filter, BPF, which is contained in the circulating optical fiber loop; the circulating optical fiber loop, which is configured to generate frequency-hopping light pulses; the circulating optical fiber loop, which is further configured to generate a number of optical frequencies, the number being determined by the number of times a light pulse circulates through the loop; and the frequency-hopping light pulses, which increase the effective acoustic sampling rate of the DAS.

Method and device for diffuse reflectance spectroscopy comprising intensity and / or optical frequency modulation of the optical radiation. The invention relates to a method for measuring, by diffuse reflectance spectroscopy, the attenuation coefficient of a diffusing and / or absorbing part of a body (1), the method comprising the following steps: a) emission of optical radiation whose intensity and / or optical frequency are modulated, at least a part of the optical radiation, called the probe signal, irradiating the body; b) reception of a part of the probe signal scattered and reflected by the body, called the backscattered signal, and measurement of the path length d of the backscattered signal; c) measurement of the reflectance R of the part of the body through which the backscattered signal passes; d) calculation of the attenuation coefficient µ from the measured path length d and reflectance R. Figure for the abstract: Fig. 2

Optical frequency reference apparatus (10) comprising - an atomic vapor cell (1), containing a vapor of reference atoms, said atomic vapor cell (1) comprising a first end (41) having a first window (4) and a second end (61), - a laser source (11) for generating a laser probe beam (3) adapted to excite a two-photon optical transition of said reference atoms, - an optical detector (14), adapted to detect a fluorescence signal emitted by said reference atoms, and - at least one reflective element (5, 15) wherein the laser source (11), the atomic vapor cell (1) and the at least one reflective element (5, 15) are configured such that, in operation, the probe beam (3) enters the atomic vapor cell (1) through said first window (4) at said first end (41) and crosses said vapor of reference atoms until said second end (61) through a defined optical path in a first forward direction (3a), the probe beam (3) is reflected backwards by said at least one reflective element (5, 15) and crosses said vapor of reference atoms a second time through the same defined optical path, in a second direction (3b) opposite to the first forward direction (3a), characterized in that the optical frequency reference apparatus (10) further comprises means (7, 9) for absorbing the reflected laser probe beam (3) exiting from the atomic vapor cell (1) according to the second direction (3b).

The invention discloses a phase noise compensation enhancement method and system for optical fiber optical frequency transmission, and relates to the technical field of optical communication and signal processing. A local high-precision laser source is transmitted to a far end through an optical fiber and is subjected to frequency comparison with a far-end laser source in a beat frequency manner; measuring the beat frequency signal through a phase counter to obtain comparison data; a local compensation radio frequency signal and an uncompensated signal are acquired through a digital circuit, a measurement time interval of the two signals is set, then the signals are connected to a phase counter for measurement, and compensation deviation data can be obtained by subtracting the two measured phase signals. The phase noise suppression enhancement can be realized by subtracting the compensation deviation data from the comparison data, so that the phase control bandwidth of optical fiber optical frequency transmission is improved, and the signal transmission precision is further improved.

A control unit (24-1) stabilizes the frequency of a carrier-envelope offset signal of an optical frequency comb. A control unit (24-2) stabilizes the frequency of a beat signal produced by the interference between measured light from a measured light source (21) and the optical frequency comb. A detection unit (34) detects a frequency interval for each of four operations for which the frequency interval between modes of the optical frequency comb is different. An optical frequency calculation unit (30) calculates first through fourth approximate estimate values for a mode number for an initial operation on the basis of the frequency interval for each of the four operations and calculates the true mode number of the initial operation on the basis of the estimate values to calculate the frequency of the measured light.

An optical comb light source outputs an optical comb having a plurality of modes. The optical comb light source includes an optical comb generating section, an optical frequency changing section, and a mode optical frequency controlling section. The optical comb generating section generates the optical comb. The optical frequency changing section receives a reference wavelength light having a predetermined optical frequency and changes the optical frequency of the reference wavelength light for output. The mode optical frequency controlling section controls a mode optical frequency that is an optical frequency of one mode of the plurality of modes such that a difference between the mode optical frequency and a target optical frequency that is an optical frequency of an output from the optical frequency changing section has a predetermined value. The optical comb generating section changes optical frequencies of the plurality of modes according to the controlled mode optical frequency.

A fibre optic sensing apparatus (400) is described which has an optical output path (403, 405, 404) configured to repeatedly interrogate a sensing optical fibre (402) by launching coherent optical radiation into the sensing optical fibre. A detector (407) is configured to receive optical radiation that is Rayleigh backscattered from the sensing optical fibre and output a detected backscatter signal in response to each interrogation and a processor (408) processes the detected backscatter signal. The apparatus is operable in a frequency swept mode, in which the sensing optical fibre is interrogated with a first set of interrogations of coherent optical radiation having different optical frequencies from one another to acquire, for at least one sensing portion of the sensing optical fibre, a backscatter spectral profile (201) of a measurement value of the detected backscatter signal with frequency across a first frequency range. The processor is configured to combine a plurality of said backscatter spectral profiles (201, 202) to form a reference profile (203) with an effective frequency range greater than the first frequency range

The present application relates to the technical field of optical frequency transfer, and particularly relates to a relay system and method for realizing automatic phase locking of optical fiber optical frequency transfer, which comprises: an optical fiber beam splitter for splitting signal light into two parts; an acousto-optic modulator for frequency shifting; a relay laser for generating regenerative laser; a photodetector for beat frequency between signal light and regenerative laser; a signal processing and discrimination locking unit for processing beat frequency signals and discriminating whether to lock at a target frequency; a control unit for maintaining the locking state of the regenerative laser when it is discriminated that the frequency of the regenerative laser is locked; and outputting the locked regenerative laser to the next optical fiber link after frequency shifting by a third acousto-optic modulator; and the specific method is to realize automatic frequency locking and relocking of the regenerative laser through double beat frequency signal discrimination and feedback control, and to ensure stable relay of optical frequency signals. The present application improves the long-term stability and reliability of the relay system.

In one aspect, a method of sorting cells in a flow cytometry system is disclosed, which includes illuminating a cell with radiation having at least two optical frequencies shifted from one another by a radiofrequency to elicit fluorescent radiation from the cell, detecting the fluorescent radiation to generate temporal fluorescence data, and processing the temporal fluorescence data to arrive at a sorting decision regarding the cell without generating an image (i.e., a pixel-by-pixel image) of the cell based on the fluorescence data. In other words, while the fluorescence data can contain image data that would allow generating a pixel-by-pixel fluorescence intensity map, the method arrives at the sorting decision without generating such a map. In some cases, the sorting decision can be made with a latency less than about 100 microseconds. In some embodiments, the above method of sorting cells can have a sub-cellular resolution, e.g., the sorting decision can be based on characteristics of a component of the cell. In some embodiments in which more than two frequency-shifted optical frequencies are employed, a single radiofrequency shift is employed to separate the optical frequencies while in other such embodiments a plurality of different radiofrequency shifts are employed.

An optical atomic clock can include a group of optical frequency references. A system for improving frequency stability in the clock output signal can use an optical combination of the group of optical frequency references. The system can include a first optical frequency reference comprising an output configured to generate a first optical signal; a second optical frequency reference comprising an output configured to generate a second optical signal; an optical frequency comparator configured to generate a first electrical feedback signal based on an optical combination of the first optical signal and the second optical signal; and an optical frequency comb, wherein the first optical frequency reference is configured to receive the first electrical feedback signal; and modify the first optical signal based on the first electrical feedback signal, wherein the optical frequency comb is configured to output a radio-frequency electrical signal based on the modified first optical signal.

The invention provides an optical microphone demodulation method and system based on a digital optical comb, and the method comprises the steps: carrying out the inverse fast Fourier transform of a data sequence of a constant-amplitude pseudo-random phase relation, and converting the data sequence into an analog signal; performing light splitting on the optical signal to obtain two paths of optical signals; one path of optical signal is used as a reference optical signal, and the other path of optical signal is subjected to optical frequency comb modulation through an analog signal to obtain a measurement optical signal; enabling the target sound wave to act on the measurement optical signal, causing the spectral characteristic offset of the measurement optical signal through an acoustic-optical coupling effect, and obtaining an offset optical signal; performing coherent detection on the reference optical signal and the offset optical signal to obtain a detection signal; and sampling the detection signal, and analyzing the target sound wave based on the sampled data. According to the invention, tiny optical frequency change caused by sound signals can be captured, and high-precision application scene requirements can be met; tiny optical frequency deviation caused by extremely weak sound can be clearly distinguished, and high-sensitivity and high-resolution detection of weak sound signals is achieved.

The invention provides an optical frequency scanning interference absolute distance measurement system and a stable reference construction method thereof. The optical frequency scanning interference absolute distance measurement system comprises a measurement interference module, an auxiliary interference module, a frequency stabilization laser reference module and a laser synchronous control and signal resolving assembly. The measurement interference module generates a beat frequency interference signal related to a to-be-measured space distance; the auxiliary interference module generates beat frequency interference signals related to instantaneous optical frequencies of the first tunable laser and the second tunable laser, monitors the optical frequencies of the first tunable laser and the second tunable laser in real time, and corrects frequency sweep nonlinear errors of the first tunable laser and the second tunable laser; a long fiber bragg grating string is arranged on a measuring arm of a Mach-Zehnder interferometer in the auxiliary interference module; the frequency stabilized laser reference module generates a beat frequency interference signal related to the optical path difference of the auxiliary interference module to compensate the optical path drift of the auxiliary interference module; the laser synchronous control and signal resolving assembly resolves a distance value to be measured according to interference signals generated by the three modules.

The present disclosure relates to a method for performing an additive manufacturing operation to form a structure by processing a photopolymer resist material. A laser beam is directed at a tunable mask. At least one emergent beam is collected from a plurality of emergent beams emerging from the tunable mask. The at least one emergent beam is collimated to create a collimated beam. Each emergent beam from the tunable mask has a plurality of beam lets of varying or identical intensity, and each beam let emerges from a unique subsection or region of the tunable mask. The collimated beam is focused into a laser beam which is projected as an image plane onto or within the photopolymer resist material, such that the same optical path length is created between the tunable mask and the focused image plane for all optical frequencies of the focused laser beam. The focused laser beam illuminates a select pattern of subsections on the tunable mask for a finite duration of time to cause simultaneous polymerization of select portions of the photopolymer resist material corresponding to the select pattern.

The present disclosure proposes an optomechanical pressure-measurement system for measuring an ambient pressure level, the system comprising a fiber having a first fiber end and a second fiber end, an optomechanical cavity being mounted at the first fiber end and composed of a first membrane element and a second membrane element spaced apart from each other, with the first membrane element contacting the first fiber end, at least one light beam generating device coupled to the second fiber end and structured to generate and direct light beams, each light beam having a certain optical frequency, via the fiber on the optomechanical cavity, and a light sensing member coupled to the second fiber end, wherein the at least one light beam generating device is structured to direct a first light beam with a first optical frequency on the optomechanical cavity, wherein the first light beam is modulated at a modulation frequency within a bandwidth of a mechanical resonance frequency of the second membrane element, wherein the at least one light beam generating device is structured to direct a second light beam with a second optical frequency on the optomechanical cavity; and wherein the light sensing member is structured to detect part of the second light beam reflected by the optomechanical cavity and to determine the ambient pressure around the optomechanical cavity based on a change of the oscillation amplitude of the second membrane element.

The present invention relates to the technical field of fiber optic frequency transmission, and specifically to a distributed fiber optic frequency transmission method and system. The distributed fiber optic frequency transmission system consists of a transmitting end and a plurality of receiving ends, which are connected by an optical fiber link. The optical signal transmission module at the transmitting end divides the laser light generated by the laser into reference light and modulated light. The modulated light is transmitted to the receiving end after positive frequency shift and wavelength division multiplexing, and the return light is received at the same time. The signal processing module processes the beat frequency of the reference light and the return light to obtain a radio frequency signal, and then performs phase processing to obtain an instantaneous frequency value and converts it into an optical signal through modulation by an optical transmitter. The optical modulator module at the receiving end demodulates the modulated optical signal to obtain an instantaneous frequency value, and uses the frequency value to drive the modulator at the receiving end to obtain the final optical frequency signal. The system realizes distributed high-precision optical frequency transmission.

Ion optical frequency standard automatic control software adopts the design concept of system integration, the system is developed by adopting the LabVIEW language, the whole-process software and hardware control requirement in an ion optical frequency standard experiment is met, and automatic intelligent control is achieved. The method specifically comprises the steps of setting experimental parameters in an ion optical frequency standard experiment, controlling, detecting and reading experimental data of the ion optical frequency standard experiment, carrying out data processing and calculation work such as transition probability calculation and the like, controlling and adjusting the parameters by utilizing PID to realize system closed-loop locking, and storing the experimental data. And a man-machine interaction interface which is simple and beautiful and has high fault tolerance in an interaction mode is designed, so that the method is simple, convenient and easy to use, and the working complexity of an ion optical frequency standard experiment is effectively reduced.