173 results about "Atomic frequency standard" patented technology

The present invention discloses a miniaturized rubidium atomic frequency standard cavity-cell system, wherein, a microwave cavity cylinder is made from high magnetic permeability material; the microwave cavity cylinder is sleeved with a heating cylinder; a pump light incident port of the heating cylinder is also provided with a convex lens which gathers and transmits rays emitted by a rubidium spectral lamp into a microwave cavity; a C field coil is directly wound on a dielectric cylinder arranged between the microwave cavity cylinder and an absorption cell; a cusp on the tail part of a light-filtering cell is concentrated at the center of a circular plane at the end of the cell; a cusp on the tail part of the absorption cell is concentrated at the edge of a circular plane at the end of the cell; a photocell and a snap-off diode are fixed on the end face of the inner wall of a cavity end cover which can be movably fixed. The present invention has no machinery regulating rod inside the cavity, uses an intracavity frequency doubling mode, adopts a cylindrical TE111 mode and a dielectric filling method to get rid of the complex structure of a magnetic shield cylinder in the prior art, and reduces the volume of the cavity-cell system. As the pump light incident port of the heating cylinder is provided with the convex lens to increase the light intensity of pump light, the performance of the cavity-cell system is guaranteed. A mobile photoelectric component is adopted for cavity frequency fine adjustment, which is convenient for debugging and cannot cause field form distortion.

The invention relates to a two-dimensional magnetic-optical trap system, which belongs to the field of neutral cold atom generation technology, and is characterized in that saddle-type reversed Helmholtz coils are adopted for forming the magnetic-optical trap system. The device is compact in integral mechanical structure and easy for miniatured and engineering application; by utilizing the inherent characteristics, such as compact structure, low installing precision requirement and better radial magnetic field gradient uniformity, of the saddle-type reversed Helmholtz coils, electricity power consumption required for forming a magnetic-optical trap is reduced; through controlling atom steam pressure intensity by electrified current, continuous cold atom sources with low speed, high throughput and small divergence angle are obtained, and a better engineering application platform is provided for an atomic frequency standard, an atom interference gyroscope or other cold atom physical experiments.

The invention discloses a loop response time measuring device and method used for an atomic frequency standard. The device comprises an oscillation module, an executing module and a signal detecting module, wherein the oscillation module is used for receiving an output signal of a servo loop of an atomic frequency standard and outputting the signal after reversing the phase of the output signal of the servo loop of the atomic frequency standard; the executing module is used for acting according to the output signal of the oscillation module to control the quantum system of the atomic frequency standard to finish the quantum frequency discrimination; and the signal detecting module is used for measuring the oscillation period of the oscillation loop according to the output signal of the oscillation module, and the oscillation loop consists of an oscillation module, an executing module and an atomic frequency standard. The method comprises the following steps of: obtaining the oscillation period of the oscillation module; measuring the oscillation period of the oscillation loop; and calculating the loop response time of the atomic frequency standard according to the oscillation period of the oscillation loop and the oscillation period of the oscillation module. By adopting the device and the method provided by the invention, the loop response time of the atomic frequency standard system can be measured accurately.

The invention relates to a small CPT atomic clock physical system, and belongs to the technical field of atomic frequency standard. The physical system comprises a laser portion and an atom air chamber portion. The laser portion comprises a VCSEL laser tube, an aperture diaphragm, and a [lambda]/4 wave plate. The atom air chamber portion comprises an atom air chamber, a C field coil, a thermistor, a low electromagnetic film electric heating sheet, and a photoelectric detector. The C field coil uses a reverse Helmholtz coil structure to realize. Heating methods of the low electromagnetic film electric heating sheet and high-frequency AC electric heating are used to heat the atom air chamber. The system uses a vacuum heat insulation technology to package. The output frequency of the physical system is high in stability, stable in performance, small in volume, low in power consumption, and low in cost, and is especially suitable to be used for a glass type atom air chamber whose sealing port is on the central position of a cylindrical surface.

The invention discloses a modified passive typed rubidium atom frequency scale servo controlling method and servo control circuit, which is characterized by the following: gathering and processing the quantum frequency discriminating signal through servo mode according the four double frequency modulating signal; judging the frequency of the microwave polling signal within the locking scale of atom adsorbing line breadth or at release locking condition; utilizing quantum correcting information to repair the frequency value of synthetic modulating signal; realizing the seal locking of entire machine. The invention adopts digital DDS and processor chip to integrate atom frequency marking servo part and synthetic part organically, which modifies the present miniaturized circuit structure to realize the seal locking of entire machine.

In an apparatus using optically excited atomic media, such as an atomic frequency standard, a source providing a controlled emission of light for exciting the D₁ and/or D₂ resonance lines of an alkali gas, such as rubidium or cesium, is controlled by an output generated by digital electronics from the light intensity signal of a light sensor for light transmitted by the alkali gas, an output for representing ambient temperature, and a light intensity-ambient temperature algorithm to substantially eliminate changes in light intensity due to light source aging for the purpose of reducing changes in temperature sensitivity of the apparatus as a function of time and the light-shift contribution to the frequency aging of the standard.

The invention discloses an atomic frequency standard and a servo locking method and belongs to the technical field of atomic frequency standards. The atomic frequency standard comprises a voltage controlled crystal oscillator, a comprehensive module, an amplitude stabilizing module, a radio frequency doubling module, a microwave mixed frequency doubling module, a physical unit and a servo module. The comprehensive module is used for generating comprehensive modulation signals. The amplitude stabilizing module is used for converting the amplitude of the comprehensive modulation signals to a preset value to obtain the amplitude-stabilized comprehensive modulation signals. The radio frequency doubling module is used for doubling frequency of output signals of the voltage controlled crystal oscillator to obtain frequency doubled signals. The microwave frequency doubling module is used for mixing and doubling the amplitude-stabilized comprehensive modulation signals and the frequency doubled signals to generate microwave search signals. The physical unit is used for subjecting the microwave search signals to quantum frequency discrimination to generate quantum frequency discrimination signals. The servo module is used for subjecting the quantum frequency discrimination signals to synchronous phase discrimination and generating rectifying voltage to act on the voltage controlled crystal oscillator. By converting the amplitude of the comprehensive modulation signals to the preset value to obtain the comprehensive modulation signals with stable amplitude, output frequency accuracy of the integral atomic frequency standard is improved.

The invention provides a technical scheme of simultaneously and precisely tracking a plurality of space objects only based on carrier observation data of ground monitoring equipment driven by an atomic frequency standard for fulfilling the purposes of high-precision orbit determination of regional navigation satellites and precise passive tracking of non-cooperative space objects. The invention designs a parameter evaluation estimation scheme of precise orbit determination only based on carrier phase data and provides a novel carrier phase cycle slip detection and repair method. The method makes full use of priori orbit and prior atomic clock speed information and is suitable for static users. The method is applied to orbit determination processing of an MEO (Medium Earth Orbit) satellite of a COMPASS system and is only based on carrier phase data of 6 regional ground stations, the mean residual of arc length orbit determination results of three days is 0.18m, and the mutual differences of one-day-arc overlap orbit are 0. 61m and 8. 09m in radial direction and three-dimensional position respectively; the mean residual of laser comparison is 0.28m; the mean residual of forecast for 24 hours and laser alignment is 1.34m. Compared with that of the prior art, the orbit determination precision is improved by 1 order.

The invention discloses a rubidium atomic frequency standard and a frequency absolute value correction circuit thereof, belonging to the field of atomic frequency standards. The rubidium atomic frequency standard includes a voltage-controlled crystal oscillator, a physical unit and an electronic circuit, and the physical unit includes a microwave cavity, a C field coil arranged outside the microwave cavity, and a constant current source device electrically connected to the C field coil , the physical unit further includes a frequency absolute value correction circuit, and the frequency absolute value correction circuit includes a variable resistor connected in series between the constant current source device and the C-field coil. In the embodiment of the present invention, the magnitude of the current in the C field coil is adjusted by the frequency absolute value correction circuit, which changes the strength of the magnetic field provided by the atoms in the physical unit, and can adjust the atomic transition frequency, and then fine-tune the output frequency of the entire atomic frequency standard , to ensure the accuracy and stability of the atomic frequency standard.

The invention discloses a device used for material ferromagnetism and magnetization performance detection. The device comprises a laser device, linearly polarized light beams, a Glan-Thompson polarizer, an electromagnetic shielding cover, a radio frequency shielding box, a magnetic shielding cylinder, an axial scanning field coil, a heating and heat preservation module, atomic vapor bubbles, a light amplification detection module, a conveying tube sealing block, a conveying tube, a solenoid coil, a positioning frame and a grooved loading warehouse. The invention also discloses a method used for material ferromagnetism and magnetization performance detection. The device is integrated in structure and convenient to operate, material ferromagnetism and magnetization performance detection is acquired through nonlinear magneto-optical resonance dispersion signals, and the device has the characteristic of ultrahigh-sensitivity magnetic measurement and practical value in material selection of atomic frequency standards, atomic magnetometers and laser detection magnetic resonance instruments.

The invention discloses an optimized passive rubidium atomic frequency scale servo control circuit. In the optimized passive rubidium atomic frequency scale servo control circuit, a non-integer voltage-controlled crystal oscillator with the resonant frequency being a non-integer MHz and the self-frequency-doubled function; double-frequency signals output by the non-integer voltage-controlled crystal oscillator undergo frequency modulation, frequency multiplication and intracavity microwave frequency multiplication, and then excite atomic ground state 0-0 transition of a physical system; the microwave exciting signals undergo frequency discrimination by utilizing the transition frequency and converted into error electrical signals through a photocell; and the correction voltage is obtainedthrough 122-Hz synchronous phase discrimination and a low-pass filter so as to control the non-integer voltage-controlled crystal oscillator to be in a locking state, thus hyperfine transition frequency stability transferring of rubidium atoms is realized, and accurate and stable output of practical rubidium atom frequency standard signals is realized through double direct digital frequency synthesizers designed by a CPLD (complex programmable logic device). The optimized passive rubidium atomic frequency scale servo control circuit has the advantages of simple structure, convenience for debugging, simplified circuit structure and the like, is beneficial to improvement of the integration degree and miniaturization of rubidium atomic frequency scale, and has an extremely good application prospect.

The invention discloses an atomic frequency standard servo method with temperature compensation and a circuit and belongs to the field of atomic frequency standards. The method comprises the following steps. A light detecting signal output by a physical unit of a atomic frequency standard is amplified, and synchronous phase discrimination of the amplified signal is performed so as to obtain a deviation rectifying signal. A work environment temperature of a pressure controlled crystal oscillator is obtained when the atomic frequency standard works, and an obtained difference value of the work environment temperature and a reference work temperature is converted to be a compensate voltage. The compensate voltage is utilized for compensating for the deviation rectifying signal so as to obtain a pressure controlled voltage, and the pressure controlled voltage acts on the pressure controlled crystal oscillator. By converting the difference value of the work environment temperature and the reference work temperature to be the voltage when the pressure controlled crystal oscillator works, compensating for the voltage to the deviation rectifying signal so as to obtain the pressure controlled voltage and enabling the pressure controlled voltage to act on the pressure controlled crystal oscillator, influences on output frequency of the pressure controlled crystal oscillator by the work environment temperature are reduced, and frequency output by the pressure controlled crystal oscillator is stable and precise.

A frequency change detector splits a frequency standard signal into two undelayed frequency signals, one of which is delayed by a predetermined amount. The delayed signal is then mixed with the undelayed frequency signal into a mixed signal that is further filtered and amplified for providing an output signal indicating frequency changes of the frequency standard signal. The mixed frequency signal indicates frequency changes of the original frequency standard signal without reference to another frequency standard. This frequency change detector is well suited for use on satellites as an early warning detection of changes in on-board atomic frequency standards.

This invention discloses a rubidium atomic frequency standard microwave resonant cavity, which is composed of the resonant ring, support tube, cylindrical cavity, rubidium absorption foam, rubidium filter foam, heating pipe, heating pipe block, C coil, and etc. The rubidium absorption and filter foam insert into the support tube, the media ring inserts into the position between the support tube and cylindrical cavity, the resonant ring inserts into the position between the media ring and rubidium absorption foam, the cylindrical cavity sets out of the media ring linking the support tube by screws, the heating triode sets in the heating tube block, and the block links the support tube and cylindrical cavity through screws.

The invention relates to an integrating sphere cooling and microwave integrating cavity used for miniaturized cold atomic frequency standard, which is formed by connecting an integrating sphere, a cylindrical microwave cavity, a flange and a four-way connector through supporting screws. The integrating sphere cooling and microwave integrating cavity has the characteristics of having the advantages of mature technologies, easiness in processing and large uniform central microwave field region for the cylindrical microwave cavity and having the advantage of cooling for the integrating sphere.

The invention discloses a control system and a control method capable of automatically judging and setting a laser frequency and power. According to the invention, a double-laser structure is adopted; a main control unit can automatically search and automatically judge an output frequency of a main laser according to a spectrum signal, and automatically locks the frequency onto an atom or molecule spectral line after automatically optimizing an output power of the main laser to a target power; after outputs of a slave laser and the main laser are subjected to beam combination, a beat frequency signal is generated, and the main control unit can automatically judge a size relationship of the output frequencies of the main laser and the slave laser so as to accurately and automatically judge the output frequency of the slave laser, after the output power of the slave laser is automatically optimized to the target power, a frequency locking error signal is generated by utilizing the main control unit, and in a range of 80GHz, locking on the frequency of the slave laser is implemented; and the method disclosed by the invention can be widely applied to the technical fields of fundamental researches and precision measurement of laser cooling, atomic frequency standards, an atom interferometer, a laser wavelength meter and the like.

The invention discloses an improved rubidium atomic frequency standard spectral lamp device which comprises a spectral lamp, a radio frequency oscillation circuit, a constant temperature sleeve and a constant temperature control circuit, wherein the radio frequency oscillation circuit comprises a filter circuit, an amplifying circuit, an oscillation frequency selection circuit, a temperature compensation circuit and a feedback resistor which are sequentially connected; the amplifying circuit comprises a transistor and a first bias resistor, wherein the two ends of the first bias resistor are respectively connected with a transistor collector and a transistor base; the temperature compensation circuit is used for reducing the current change of the transistor collector with temperature; one end of the temperature compensation circuit is connected with the first bias resistor, and the other end and a connection point of the transistor base are connected with an input end of the radio frequency oscillation circuit; the feedback resistor is connected in series with the emitter of the transistor; and the transistor and the temperature compensation circuit are located in the same temperature zone. The spectral lamp device disclosed by the invention can improve the stability of the rubidium atomic frequency standard output frequency.

The invention discloses a passive laser gyroscope based on an ultra-stable laser. The passive laser gyroscope comprises an ultra-stable laser source device, a high Q-value annular cavity interferometer device, and a beat frequency detecting device. An ultra-stable laser source with both short and long stability is obtained by locking the frequency of lasers output form a laser to an ultra-stable Fabry-Perot resonance peak and simultaneously locking to a femtosecond optical comb linked to an atomic frequency standard. The circumference of an annular cavity is locked to the frequency of the ultra-stable laser source injected in the counterclockwise direction. The frequency of the laser injected in the clockwise direction is locked to the same resonance peak of the cavity. The beat frequencydetecting device detects the beat frequencies of the overflow light in two directions in the cavity to obtain a Sagnac signal, and angular spin velocity is determined by the signal. According to the passive laser gyroscope based on the ultra-stable laser, the interference signal-to-noise ratio of the laser gyroscope is improved, and the stability of the scale factor of the gyroscope is improved byusing an ultra-stable laser as the injection light source of the passive laser gyroscope, so that the stability of the whole gyroscope system is improved, the integration average time is prolonged, and a better rotation measurement resolution can be obtained.

The invention discloses a signal to noise ratio evaluation device and a signal to noise ratio evaluation method for a rubidium atomic frequency standard, and belongs to the field of atomic frequency standards. The device comprises a first analogue-to-digital sampling unit, a second analogue-to-digital sampling unit and a master control unit. The method comprises the following steps of: drawing an absorption curve according to a corresponding relationship between a frequency discrimination signal and a voltage point of first sweep voltage; drawing a frequency discrimination curve according to a corresponding relationship between a voltage control signal and a voltage point of second sweep voltage; calculating an absorption factor according to the absorption curve; calculating a line width according to the frequency discrimination curve; acquiring a preset modulation depth; and calculating the signal to noise ratio of the rubidium atomic frequency standard by using the absorption factor, the line width and the modulation depth. By the device and the method, the accuracy of the signal to noise ratio of the rubidium atomic frequency standard is improved.

The invention discloses a method and a device for optimizing short-term stability parameters of an atomic frequency standard, which belong to the field of the atomic frequency standards. The method comprises the steps that a plurality of working parameter points are set; each working parameter point includes a plurality of experiment points which correspond to different parameters to be optimized, each parameter to be optimized corresponds to the plurality of experiment points, and the quantities of the corresponding experiment points are the same, the experiment points corresponding to the same parameter to be optimized are evenly distributed in a value area including two end points of the parameter to be optimized, at most one same experiment point exists in every two working parameter points, and the frequency of each experiment point in all the working parameter points is the same; each parameter to be optimized includes modulation depth, modulation frequency and microwave power; according to each working parameter point, the modulation depth, the modulation frequency and the microwave power are respectively regulated; and frequency discrimination gradient of the atomic frequency standard corresponding to each working parameter point is calculated, and the optimal working parameter point is selected. The method and the device improve the short-term stability of the atomic frequency standard.

The invention discloses a pulse signal source device, and belongs to the field of atomic frequency standards. The device comprises an initial signal source, a control module, a first digital frequency synthesizer, a second digital frequency synthesizer, a phase-looed loop frequency divider, an attenuation matching network, a frequency multiplying and mixing module and a power amplifier. The initial signal source is used for outputting frequency signals; the control module is used for generating reference signals according to the frequency signals, generating keying frequency-modulated signals and generating time sequence control signals by taking the frequency signals as reference; the first digital frequency synthesizer is used for taking the reference signals as reference, performing keying frequency modulation by the keying frequency-modulated signals and generating modulating signals; the second digital frequency synthesizer is used for generating original pulse signals under the control of the time sequence control signals; the phase-locked loop frequency divider is used for processing the original pulse signals by set fractional frequency and outputting pulse signals; the attenuation matching network is used for compensating the pulse signals; the frequency multiplying and mixing module is used for frequency multiplying and mixing of the pulse signals and the modulating signals to acquire optical-detection resonance signals; the power amplifier is used for power amplification of the optical-detection resonance signals.

The invention discloses a device for reducing the microwave power frequency shift of an atomic frequency standard. The device comprises a synchronous phase discrimination module, a voltage sampling module, a photodetection signal feedback module and a differential amplification module, wherein the synchronous phase discrimination module is used for performing synchronous phase discrimination on aphotodetection signal output by a physical system to obtain a deviation rectifying voltage; the voltage sampling module is used for converting a photodetection signal into a photodetection voltage signal; the photodetection signal feedback module is used for calculating a difference value between a maximum peak and a minimum peak of the photodetection voltage signal transmitted by the detection voltage sampling module, and amplifying the difference value to obtain a DC voltage; and the differential amplification module is used for amplifying the DC voltage transmitted by the photodetection signal feedback module and the deviation rectifying voltage transmitted by the synchronous phase discrimination module, calculating the difference value between the DC voltage and the deviation rectifying voltage to obtain a quantum deviation rectifying signal, and making the quantum deviation rectifying signal function in a voltage-controlled crystal oscillator. The device for reducing the microwave power frequency shift of the atomic frequency standard can reduce the microwave power frequency shift, thereby improving the frequency stability of a rubidium atomic frequency standard. The invention also discloses a method for reducing the microwave power frequency shift of the atomic frequency standard.