79 results about "Atom interferometer" patented technology

The invention discloses a method for measuring a detection inclination angle of a two-component atomic shearing interferometer. The method comprises the following steps: constructing an inclination angle set of an angle swinging device; when the atoms are acted by the pi Raman laser and the second pi / 2 Raman laser, the reflecting mirror rotates by an angle; alternately detecting multiple groups of odd-numbered groups and even-numbered groups; traversing all dip angles in the dip angle set; and fitting and calculating the actual included angle of the longitudinal direction of the imaging surface of the CCD camera relative to the Z-axis direction. The invention further discloses a measuring device for the detection inclination angle of the two-component atom shearing interferometer. According to the method, an existing atom shearing interferometer can accurately measure the inclination angle of a detection system of the atom shearing interferometer, so that the problems of noise and system errors caused by the fact that the inclination angle of the detection system of the atom shearing interferometer does not return to zero are solved, and drifting of differential measurement of the two-component atom interferometer caused by inclination angle changes is restrained.

Various optical systems for use in a light pulse atomic interferometer (LPAI)-based one-, two-, or three-axis accelerometer or gyroscope are disclosed. As an LPAI accelerometer or gyroscope may employ many different laser beams to implement the LPAI functionality, ways of combining these different laser beams to thereby simplify the optical systems are desired. The cooling laser beam portion of the optical system may be simplified using one or more reflective grating chips. The Raman laser beam optics may be simplified using combiners and separators. For LPAI systems sensing along three axes, various optical switching schemes may be employed, including ones that generate variable data-rates with a primary sensing axis having a higher data-rate than the secondary sensing axes. Further, by combining various laser beams in a time-multiplexed manner, the number of optical fiber tethers to a sensor head may be reduced.

The invention belongs to the technical field of atomic inertial measurement, and discloses a continuous measurement atomic interferometer control method and system. The method comprises the steps that atoms are sequentially subjected to N times of stimulated Raman transition, the time difference between the stimulated Raman transition is T, atom interference is achieved, in the same vacuum cavity, a plurality of atomic groups are sequentially subjected to atom interference, when the Kth atomic group is subjected to the nth time of stimulated Raman transition, the (K + 1) th atomic group and the Kth atomic group share Raman laser, and the Kth atomic group and the (K + 1) th atomic group share Raman laser. And the first stimulated Raman transition of the (K + 1) th atomic group is synchronously carried out, so that the atomic interference of the atomic group in the vacuum cavity at each moment can be ensured, the output result of the interferometer covers the working time of the whole interferometer, the continuous measurement of the atomic interferometer is realized, and n is less than or equal to N.

An adjuster performs simultaneous irradiation of M laser beams to an atomic beam, where M is a predetermined integer satisfying 3≤M. The course of each of the M laser beams intersects with the course of the atomic beam. A component, in a direction perpendicular to the course of the atomic beam, of the sum of radiation pressure vectors that the M laser beams respectively have is zero. A component, in a direction of the course of the atomic beam, of the sum of the radiation pressure vectors that the M laser beams respectively have is negative for atoms having speeds greater than a predetermined speed, and positive for atoms having speeds smaller than the predetermined speed.

This invention relates to a Bragg light generation system and method suitable for Bragg-type atomic interferometers. The system includes: a laser for generating a first laser beam with a frequency in a preset atomic absorption peak band; an optical circulator for propagating the first laser beam to a cascaded acousto-optic modulator and receiving two third laser beams returned from the cascaded acousto-optic modulator; a cascaded acousto-optic modulator for diffracting the first laser beam into two second laser beams with opposite propagation directions through Bragg diffraction of two acousto-optic crystals; an optical assembly for performing secondary diffraction on the two second laser beams and reflecting the two mutually perpendicular second laser beams to the cascaded acousto-optic modulator; and an output module for splitting and sampling the two third laser beams and modulating the sampled third laser beams into Bragg laser beams in the target frequency band. This invention reduces the path separation of the two Bragg laser beams by using a quasi-common optical path, thereby reducing phase noise and improving measurement accuracy.

The invention discloses an inertial navigation system calibration method and device based on a cold atom interferometer, and relates to the technical field of inertial navigation, guidance and control, an accelerometer and a gyroscope are used for collecting original data and correcting errors, and then calibration is carried out by combining the earth gravity acceleration and rotation angular velocity collected by the cold atom interferometer. And through calculation of an attitude rate differential equation and a displacement angular rate differential equation and attitude fusion, accurate attitude output is obtained. According to the invention, the pose measurement precision is greatly improved; the system has an autonomous traceability, and gets rid of the dependence of traditional calibration on laboratory equipment or specific devices; the rearranged algorithm enhances the precision of long-time navigation in a complex environment, and is suitable for long-endurance and combined navigation systems; the online calibration function of the calibration system can correct system parameter drift in real time, continuous high-precision operation of the navigation system is guaranteed, and the overall performance and reliability of the inertial navigation system are effectively improved.

The invention relates to a final state detection device for an atom interferometer and a detection method thereof. The device comprises a detection laser collimator, a first coupling lens, a resonant cavity, a second coupling lens, a photoelectric detector and a computing terminal, the resonant cavity comprises a first cavity mirror and a second cavity mirror which are located on the two sides of a vacuum cavity of the atom interferometer and are oppositely arranged. To-be-tested atomic groups in different test states are arranged in the vacuum cavity; in each test state, the detection laser collimator is used for outputting detection laser and enabling the detection laser to enter the vacuum cavity through the first coupling lens and the first cavity mirror, and the detection laser passes through an atomic group to be tested for many times and is coupled to the photoelectric detector through the second cavity mirror and the second coupling lens. Enabling a computing terminal to obtain the transmission light power of the detection laser in each test state through a photoelectric detector, so as to determine the atomic final state population information after the atomic interference; and the detection laser resonates with the transition spectral line of the atomic group to be detected. According to the invention, the measurement precision of the final-state atomic population information can be improved.

The invention relates to a Bragg light generation system and method suitable for a Bragg atom interferometer, and the system comprises a laser device which is used for generating first laser with the frequency on a preset atomic absorption peak frequency band; the optical circulator is used for transmitting the first laser to the cascade acousto-optic modulator and receiving two beams of third laser returned by the cascade acousto-optic modulator; the cascade acousto-optic modulator is used for diffracting the first laser into two beams of second laser with opposite propagation directions through Bragg diffraction of the two acousto-optic crystals; the optical assembly is used for carrying out secondary diffraction on the two beams of second laser and reflecting the two beams of second laser which are obtained through diffraction and are perpendicular to each other to the cascade acousto-optic modulator; and the output module is used for carrying out light splitting sampling on the two beams of third laser and modulating the sampled third laser into Bragg laser of a target frequency band. According to the invention, path separation of the two Bragg laser beams is reduced through quasi-common-path, so that phase noise is reduced, and measurement precision is improved.

The application discloses a method and equipment for extracting same-frequency aliasing signals in a shear atomic interferometer. The same-frequency aliasing interference signals to be fitted are regarded as simple harmonic signals, fitted effective contrast and fitted effective phase are obtained based on the simple harmonic signals, and the contrast prior value of the first atomic interference signal and the contrast prior value of the second atomic interference signal are obtained by inversion. The same-frequency aliasing interference signals to be solved are regarded as simple harmonic signals, the measured effective contrast and the measured effective phase are obtained based on the simple harmonic signals, the absolute value of the phase deviation of the first atomic interference signal to be solved and the second atomic interference signal to be solved is calculated, and the phase of the first atomic interference signal to be solved and the phase of the second atomic interference signal to be solved are calculated. The application can reconstruct the atomic interference signals from the same-frequency aliasing interference signals to be solved, realizes the restoration of the original signals, and realizes the accurate separation of the atomic interference signals.

The invention relates to a light reflector element having several reflector surfaces which are aligned at an angle to a predefined direction of light incidence of the light reflector element, wherein the reflector surfaces can be arranged ring-shaped around a center of the light reflector element at a uniform angular distance to each other, wherein the reflector surfaces are arranged opposite each other with respect to the center of the light reflector element, so that light incident in the direction of light incidence (L) is deflected by the reflector surfaces into light rays which run towards each other in different spatial directions and meet in a central axis which runs through the center in the direction of light incidence. The invention further relates to a reflector arrangement with at least two such reflector elements and a quantum gradiometer. In general, the invention relates to the field of atom interferometers, in particular with magneto-optical traps (MOTs). In particular, the invention relates to atom interferometric gravimeters and gradiometers formed therewith.

The present disclosure relates to an inertial sensor for measuring an amount of inertia along a sensing axis. The sensor includes an atom interferometer including a pulse generator for generating one or more pulsed light beams defined by respective pulse durations to place atoms in superposition and recombine the atoms to measure interference of the atoms, the one or more pulsed light beams being configured to generate one or more pulsed light beams, the one or more pulsed light beams being defined by respective pulse durations, the one or more pulsed light beams being defined by respective pulse durations, and the one or more pulsed light beams being defined by respective pulse durations, the one or more pulsed light beams being defined by respective pulse durations. And calculating the amount of inertia based on the measured interference. The sensor further includes an auxiliary acceleration sensor configured to measure acceleration transverse to one or more of the pulsed light beams; and a control system configured to calculate a lateral offset of the atoms relative to the pulsed light beam caused by the measured acceleration transverse to the one or more of the light beams, increase the pulse duration, and adjusting the pulse timing to compensate for a reduced beam strength applied to the atoms due to the lateral offset.

The application discloses a method for measuring a detection tilt angle of a two-component atomic shearing interferometer, constructs a tilt angle set of a swing angle device; the angle of a mirror is turned between the time when atoms are subjected to the action of a pi Raman laser and a second pi / 2 Raman laser; a plurality of groups of odd number and even number are alternately detected; all tilt angles in the tilt angle set are traversed; and the actual included angle of the longitudinal direction of a CCD camera imaging surface relative to the Z-axis direction is calculated by fitting. The application also discloses a measuring device for the detection tilt angle of the two-component atomic shearing interferometer. The application enables the current atomic shearing interferometer to accurately measure the tilt angle of the detection system, thereby solving the problems of noise and system error caused by the non-zero return of the tilt angle of the detection system of the atomic shearing interferometer, and suppressing the drift of the differential measurement of the two-component atomic interferometer caused by the change of the tilt angle.

The invention discloses a complete common mode rejection two-component atom interferometer which comprises a vacuum system, detection laser, second Raman laser, third Raman laser and compensation light are arranged above the top of the vacuum system, and a reflector is arranged below the bottom of the vacuum system. The first Raman laser and the fourth Raman laser are reflected by the reflecting mirror, are incident to the vacuum system from the bottom of the vacuum system, and are propagated upwards along the extension direction parallel to the central axis of the vacuum system; by setting Raman laser of a prime specific frequency relation, a light intensity proportional relation and a spatial position relation corresponding to a first component and a second component of a cold atomic group in a vacuum system, the two-component atom interferometer can realize complete suppression of common-mode noise during differential measurement. According to the invention, the technical bottleneck problem that the measurement precision is limited due to the fact that the noise of the internal-state controllable two-component atom interferometer cannot completely suppress the common mode is solved.

Provided is an apparatus and method in which, in a first region that traps atoms in a first state by a first light and a magnetic field, atoms are optically pumped into a second state and thereby trapped by magnetic force. The atoms in the second state trapped in the first region are moved from the first region to a second region by force of gravity or the radiation pressure from second light. In the second region, the second light is radiated on the atoms in the second state, and the atoms in the second state are thereby cooled. The atoms are optically pumped into a third state that is insensitive to magnetic fields and thereby released from a magnetic trap and transported to a post device by a moving optical lattice or an optical dipole guide.

The present invention relates to a device and method for enhancing the sensitivity of rotational measurement using a multi-loop atomic interferometer. The device and method are characterized by: an atomic cluster is initially positioned at the upper center of a vacuum chamber; a pair of control lasers are positioned outside the left and right sides of the vacuum chamber, aligned laterally with the initial position of the atomic cluster; a pair of ejection lasers are positioned above and below the vacuum chamber, aligned vertically with the initial position of the atomic cluster; the pair of control lasers and the pair of ejection lasers constitute a multi-loop interferometer; the pair of control lasers is used to split and combine the atomic cluster in the lateral direction of atomic motion; the pair of ejection lasers is used to initially eject the atomic cluster and then eject it again during the interference process in the direction of atomic motion, ultimately closing the interferometer at the initial ejection position; a detection laser is used to illuminate the atomic cluster after completing n-loop interference path closure; a fluorescence collection device converts the interference signal into an electrical signal, which is transmitted to a computer via a data acquisition device. The present invention achieves an n-fold increase in sensitivity with a short interference time.

The present invention provides a method and system for fitting interference fringes for a cold atom interferometer gyroscope. The method comprises: obtaining a mathematical model of the interference fringes of the cold atom interferometer gyroscope, linearizing the interference fringes model based on trigonometric functions to obtain a corresponding linear function; solving the linear correlation coefficient in the linear function using the least squares method based on the currently sampled transverse fringe phase and atomic transition probability; and expanding the range of fringe initial phase values. Within the expanded range of fringe initial phase values, the interference fringes are fitted based on the linear correlation coefficient and the real-time sampled transverse fringe phase and atomic transition probability. This solution ensures the accuracy of interference fringe fitting and improves the fitting speed, meeting the real-time requirements of interference fringe fitting.

A large-dynamic and high-sensitive measurement protocol of an evanescent-field-mode guided atom interferometer accelerometer is disclosed. Cold atoms of a finite temperature are one-dimensionally guided in an evanescent field optical dipole trap. The first-step pathfinder protocol employs the revival of atomic coherence, i.e., the recovery of atomic fringe visibility to capture global interferometric signature to provide the information (e.g., a large-range of approximate acceleration sensing) to optimize the physical parameters for the second-step high-precision guided LPAI measurement. The contrast of atomic fringe visibility returns to unity given a specific interrogation time during the pulse sequence. To ensure the optimal interrogation time, the method employs a time-scanning sequence about the anticipated optimal interrogation time. The anticipated optimal interrogation time is determined via a conventional inertial measurement unit co-sensor or through the use of a look-up table. The method may alternatively employ a phase-scanning sequence.

According to the present invention, in a first region that traps atoms in a first state by means of first light and a magnetic field, atoms are optically pumped into a second state and thereby trapped by magnetic force. The atoms in the second state trapped in the first region are moved from the first region to a second region by means of force of gravity or the radiation pressure from second light. In the second region, the second light is radiated on the atoms in the second state, and the atoms in the second state are thereby cooled. The atoms are optically pumped into a third state that is insensitive to magnetic fields and thereby released from a magnetic trap and transported to a post device by means of a moving optical lattice or an optical dipole guide.

A high-low temperature vacuum sample conveying device can achieve reciprocating conveying of an atom sample air chamber in high-temperature and low-temperature environments and is mainly composed of a vacuum heating assembly, a sample supporting table assembly, a non-magnetic transmission assembly and a fixed connecting base, the atom sample air chamber is fixed to the sample supporting table assembly, the vacuum heating assembly can provide the 200 DEG C high-temperature environment, and the sample supporting table assembly can provide the non-magnetic transmission assembly. And the fixed connection base is located in a low-temperature environment created by liquid helium. The vacuum sample automatic conveying device under the great temperature difference is provided for quantum precision measurement devices such as a cold atom interferometer, a superconducting gravity detector and an optical pump magnetometer, manual operation is not needed, the conditions of an atom sample air chamber at different temperatures can be directly tested conveniently, the experiment time is saved, and the experiment efficiency is improved. And in addition, the device can be matched with other cavities with magnetic shielding and low-temperature and constant-temperature effects for use, and the flexibility is high.

An electronic state splitter for atoms comprises an atom supplier, an atom movement path, a probe laser source, and a magnetic field generator. The atom supplier supplies atoms moving at a constant velocity along the atom movement path. The probe laser source supplies a probe laser propagating in the atom movement path in the same direction as or opposite to the motion of the atoms on the same axis as the atom movement path. The magnetic field generator generates a magnetic field orthogonal to the atom movement path in the atom movement path to mix the wave function of the clock upper state with the electronic state allowing electric dipole transitions, allowing pulsed excitation of clock transitions by the probe laser uniform in time and space. Accordingly, continuous spectroscopy of atomic transitions and frequency control of the probe laser are possible, which improves the stability of the atomic clock.

The application relates to a Raman laser carrier sideband ratio feedback control system and a control method thereof. The system is used for controlling an IQ modulator of a cold atom interferometer laser system. The control system comprises an F-P resonant cavity, which is used for receiving Raman laser output by the IQ modulator, and simultaneously adjusting the cavity length of the F-P resonant cavity in real time, so as to identify and output transmitted light of different frequency components to a photoelectric detector. The photoelectric detector is used for detecting the transmitted light of different frequency components, so as to output intensity signals of different frequency components to a calculation module. The calculation module is used for collecting the intensity signals of different frequency components, and calculating and outputting the Raman laser carrier sideband ratio to a feedback control module. The feedback control module is used for performing error feedback control on the IQ modulator according to the Raman laser carrier sideband ratio and a preset carrier sideband ratio expected value, so as to realize the locking control of the Raman laser carrier sideband ratio. The application can improve the measurement accuracy and long-term stability of the cold atom interferometer laser system.

The present invention provides a beam expander and collimator for a cold atom interferometer and a method for using the same, comprising: a polarization-maintaining optical fiber, a half-wave liquid crystal variable retarder, a lens group, a first 1 / 2 wave plate, a beam splitting mirror, and an optical power monitoring module; the polarization-maintaining optical fiber outputs a divergent linearly polarized laser beam, which undergoes real-time polarization state switching through the half-wave liquid crystal variable retarder, is expanded and collimated into a parallel beam through the lens group, has its initial polarization axis angle adjusted through the first 1 / 2 wave plate, and is split into a reflected light and a transmitted light through the beam splitting mirror; wherein, the reflected light enters the vacuum chamber, and the transmitted light enters the optical power monitoring module. The present invention can switch the polarization state of the laser beam in real time and monitor the changes in the polarization state and optical power of the laser beam in real time. By using one beam expander and collimator, laser beams with different polarization states required in the atomic interference measurement process can be realized, greatly reducing the complexity of cold atom trapping and interference optical arrangement, and at the same time effectively reducing the volume and application cost of the cold atom interferometer.

The invention relates to a large momentum transfer atom interferometer and method based on hollow-core optical fiber guidance, and belongs to the technical field of measurement. Comprising a first optical path assembly for transmitting a first Bragg light beam, a second optical path assembly for transmitting a dipole light beam, a third optical path assembly for transmitting a detection light beam, a fourth optical path assembly for transmitting a second Bragg light beam, a fifth optical path assembly for transmitting a correlation cooling light beam, a hollow-core optical fiber and a photoelectric detector, the fifth light path assembly outputs three groups of mutually orthogonal correlation cooling light beams which are intersected and overlapped right above the hollow-core optical fiber, the light output ends of the first, second and third light path assemblies are led to the lower end of the hollow-core optical fiber, the light output end of the fourth light path assembly is led to the upper end of the hollow-core optical fiber, and the upper end of the hollow-core optical fiber is led to the light input end of the photoelectric detector. The high-order Bragg diffraction process based on hollow-core optical fiber guidance is adopted, the size of a required light field is small, the light power is small, and the development requirement of a compact atom interferometer in the future is better met.

A method is presented for measuring motion of a moving body using an atom interferometer. The method includes: positioning at least one atom in a cavity of the atom interferometer, where the atom interferometer is attached to the moving body; splitting the at least one atom into a pair of wave-function components; guiding the pair of wave-function components along respective paths in the cavity such that the pair of wave-function components are confined spatially along the respective paths in all degrees of freedom and without interruption; coherently recombining the pair of wave-function components into the at least one atom; and measuring a property of the at least one atom after the pair of wave-function components have been recombined into the at least one atom, where the property of the at least one atom is indicative of motion of the moving body.

The invention relates to a method in which at least one ensemble of atoms is prepared in an output coupling state (Z1) and, by means of coherent control interventions acting on the at least one ensemble of atoms in an atom interferometer input state that is the same as or, after the application of further manipulation steps, different from the output coupling state (Z1), is changed into subsequent states different from the atom interferometer input state, and a matter-wave interferometry sequence, which may in particular have several loops, is carried out with the at least one ensemble of atoms. The invention further relates to an atom interferometer configured for carrying out such a method and to a computer program for carrying out such a method.

The invention belongs to the technical field of cold atom interference precision measurement, and particularly discloses an atom interference device for rotation and gravity integrated measurement, which is specifically characterized in that a first optical component is used for vertically entering Raman light from the top to control an atomic wave packet after state selection when gravity measurement is carried out so as to complete a three-pulse atom interference process; the pulse part and the pulse part are respectively used for enabling laser pulses to enter from the side surface when rotating measurement is carried out, enabling the laser pulses to interact with atoms after state selection, realizing beam splitting-reflection-reflection-beam combination of atomic wave packets, and completing a four-pulse atom interference process; the state selection detection part is used for incidence of detection light, final state detection of falling atoms is carried out, and gravity measurement and angular velocity measurement in the horizontal direction are realized. According to the invention, the integrated measurement of rotation and gravity is realized, the functionality and practicability of the cold atom interferometer are remarkably improved, and the application scene of the cold atom interferometer is widened.

This invention discloses a two-component atomic interferometer for large momentum transfer based on four-wave dual-diffraction Raman spectroscopy. It includes a vacuum system, within which cold atomic clusters comprise two components. First, second, and third Raman lasers incident on the vacuum system constitute the Raman light of the first component, while first, second, and fourth Raman lasers constitute the Raman light of the second component. Frequency variations in the third and fourth Raman lasers compensate for the Doppler frequency shift caused by the difference in recoil velocity during the large momentum transfer of the two atomic components. This invention utilizes the insensitivity of the two-component atomic interferometer to the third frequency of the Raman laser. By independently adjusting the frequency of the non-shared lasers of the two-component atomic interferometer, it achieves large momentum transfer in the two-component atomic interferometer while ensuring common-mode suppression of phase noise in the two-component atoms, and without limiting the number of recoil photons by the Doppler frequency shift difference, thus improving the accuracy of differential measurements.

The invention relates to a method for controlling and implementing an atom interferometer, in which at least one ensemble of atoms is prepared in an out-coupling state, wherein the out-coupling state describes the state after cooling procedures and / or other preparation steps or generally the state before the following steps, in which the at least one ensemble of atoms is then transferred to a transfer state different from the out-coupling state by a transfer control intervention, in which the at least one ensemble of atoms is subsequently transferred to an atom interferometer input state by at least one relaunch control intervention, in which a matter-wave interferometry sequence is then carried out with the at least one ensemble of atoms by means of coherent control interventions acting on the at least one ensemble of atoms.The invention also relates to an atom interferometer configured to carry out such a method, and to a computer program for carrying out such a method.

The invention relates to an atom interferometer with a laser light source through which first laser light can be emitted at a fundamental frequency, and with at least one light emission device through which second laser light can be emitted at a frequency that deviates from the fundamental frequency by a difference frequency, and with an atom trap in which one or more atom ensembles can be captured and irradiated with the first and the second laser light.

The utility model belongs to the field of atom inertia measurement, and particularly discloses an auxiliary device for evaluating the Coriolis force of an atom interferometer, the auxiliary device comprises a lifting rotation supporting module and an inclination detection adjusting module, and the inclination detection adjusting module comprises an inclination detection unit and an inclination adjusting unit; the inclination detection unit is used for detecting the inclination of the vacuum container; the inclination adjusting unit is located at the bottom of the vacuum container and used for supporting the vacuum container and adjusting the vacuum container to be horizontal according to the inclination. The lifting rotation supporting module can be coaxially arranged under a vacuum container of the atom interferometer and can drive the vacuum container to rotate so as to modulate the Coriolis force. According to the invention, the effect of rotating the vacuum container in the atom interferometer with high efficiency and high precision can be realized.