99 results about "Atomic vapor" patented technology

A clock including: a portable, at least partially evacuated housing; a cell being positioned within the housing and including an internal cavity having interior dimensions each less than about 1 millimeter, an intra-cavity pressure of at least about 760 Torr, and containing a metal atomic vapor; an electrical to optical energy converter being positioned within the housing to emit light through the metal atomic vapor; an optical energy intensity detector being positioned within the housing to receive the light emitted by the converter through the metal atomic vapor; at least one conductive winding around the cavity to stabilize the magnetic field experienced in the cavity dependently upon the detector; and, an output to provide a signal from the housing dependently upon the detector detecting the light emitted by the converter through the metal atomic vapor.

An atomic vapor cell apparatus and method for obtaining spin polarized vapor of alkali atoms with relaxation times in excess of one minute is provided. The interior wall of the vapor cell is coated with an alkene-based material. The preferred coatings are alkenes ranging from C18 to C30 and C20-C24 are particularly preferred. These alkene coating materials, can support approximately 1,000,000 alkali-wall collisions before depolarizing an alkali atom, an improvement by roughly a factor of 100 over traditional alkane-based coatings. Further, the method involves a combination of one or more of the following: the use of a locking device to isolate the atoms in the volume of the vapor cell from the sidearm used as a reservoir for the alkali metal vapor source, careful management of magnetic-field gradients, and the use of the spin-exchange-relaxation-free (SERF) technique for suppressing spin-exchange relaxation.

An atomic magnetometer is used to detect radio frequency magnetic fields, such as those generated in nuclear resonance experiments. The magnetometer is based on nonlinear magneto-optical rotation and pumps an atomic vapor into a quadrupole aligned state. Detection of the modulation of the polarization of a linearly polarized beam provides the radio frequency signal, which can then be processed to extract the component frequencies.

An atomic magnetometer includes an atomic vapor cell, an optical system conformed to transmit pump radiation and probe radiation through the vapor cell, and an optical detection system arranged to receive and detect probe radiation after it exits the vapor cell. Improvements in the separation of spatial channels are achieved by using a a diffractive optical element arranged to divide at least the pump radiation into a plurality of separate diffracted beams that traverse the vapor cell.

The present invention provides a method and apparatus for making atomic clocks or atomic magnetometers as self-modulated laser systems based on the physics of push-pull optical pumping. An atomic vapor cell is required to be in the laser cavity. With proper conditions, spontaneous push-pull optical pumping can occur inside the laser cavity. This causes the laser beam to be modulated at hyperfine-resonance frequency. With a fast photodetector, the modulated laser signal can be converted into the electrical signal, which serves as the atomic clock ticking signal or magnetometer signal. The self-modulated laser system does not use any local oscillator and the microwave circuit to lock the oscillator frequency to the hyperfine-resonance frequency, and therefore can consume less power and become more compact than conventional systems. This invention will benefit applications of time measurements and magnetic-field measurements.

An optical atomic magnetometers is provided operating on the principles of nonlinear magneto-optical rotation. An atomic vapor is optically pumped using linearly polarized modulated light. The vapor is then probed using a non-modulated linearly polarized light beam. The resulting modulation in polarization angle of the probe light is detected and used in a feedback loop to induce self-oscillation at the resonant frequency.

The invention relates to a preparation method for a micro-electro-mechanical system (MEMS) atomic vapor chamber and the atomic vapor chamber. The chamber is prepared by bonding a Pyrex glass sheet, a silicon wafer and a Pyrex glass sheet by an anodic bonding technology; the Pyrex glass sheet is taken as a window of the chamber; a chamber space is formed by etching or corroding the silicon wafer; paraffin packaged alkali metal such as rubidium (Rb) or cesium (Cs) is put into the chamber, and buffer gas with appropriate pressure is introduced simultaneously; paraffin is taken as a packaging material of the alkali metal, so that active alkali metal is isolated from oxidants such as oxygen, water vapor and the like in an environment; the paraffin is also used as a plating material of the chamber, so that collision between Rb or Cs atoms and a chamber wall is slowed down; and a CO2 laser is used for melting the paraffin to release the alkali metal, so that a uniform paraffin plating is formed on the chamber wall. The problem of long-term drift caused by reaction residues generated by a field preparation mode is solved, the collision between the Rb or Cs atoms and the chamber wall is slowed down, and the contrast of atomic resonance line width of the alkali metal is improved.

A magnetometer is provided comprising an atomic vapor in an enclosure, a source of light for preparing the vapor into a state exhibiting electromagnetically induced transparency, a first laser beam passing through the atomic vapor, a phase detector for detecting changes in phase of the first laser beam, and a controller which controls the light source and laser beam and receives the information detected by the phase detector in order to compute from those changes in phase a magnetic field strength in the presence of a selected background magnetic field of at least 0.001 T. Operation in the presence of a background field helps make this magnetometer suitable for diagnostic imaging applications.

A method of operating an optically pumped magnetometer (OPM) includes directing a light beam through a vapor cell of the OPM including a vapor of atoms; applying RF excitation to cause spins of the atoms to precess; measuring a frequency of the precession; for each of a plurality of different axes relative to the vapor cell, directing a light beam through the vapor cell, applying a magnetic field through the vapor cell along the axis, applying RF excitation to cause spins of the atoms to precess, and measuring a frequency of the precession in the applied magnetic field; determining magnitude and components of an ambient background magnetic field along the axes using the measured frequencies; and applying a magnetic field based on the components around the vapor cell to counteract the ambient background magnetic field to facilitate operation of the OPM in a spin exchange relaxation free (SERF) mode.

A light-pulse atomic interferometry (LPAI) apparatus is provided. The LPAI apparatus comprises a vessel, two sets of magnetic coils configured to magnetically confine an atomic vapor in two respective magneto-optical traps (MOTs) within the vessel when activated, and an optical system configured to irradiate the atomic vapor within the vessel with laser radiation that, when suitably tuned, can launch atoms previously confined in each of the MOTs toward the other MOT. In embodiments, the magnetic coils are configured to produce a magnetic field that is non-zero at the midpoint between the traps. In embodiments, the time-of-flight of the launched atoms from one MOT to the other is 12 ms or less. In embodiments, the MOTs are situated approximately 36 mm apart. In embodiments, the apparatus is configured to activate the magnetic coils according to a particular temporal magnetic field gradient profile.

The invention discloses a measurement method and measurement device for the intensity of a microwave electric field. The measurement method includes the steps of splitting a probe light generated by a first laser into two beams of identical probe light, one of which enters a rubidium cell and the other of which enters vacuum equipment; coupling light, which is generated by a second laser, entering the rubidium cell, coherently exciting hot atoms in the rubidium cell from a ground state to a rydberg state by the coupling light and the probe light, and realizing electromagnetically induced transparency in an atomic vapor chamber; applying a microwave electric field generated by a microwave source onto the hot atoms, and coupling another adjacent rydberg state onto a three-level EIT system to form a four-level system; and respectively probing the two ways of transmission light emitted from the rubidium cell and the vacuum equipment, determining the time difference of the two ways of transmission light by analyzing a dispersion relation between the two ways of transmission light, and thus obtaining the intensity of the microwave electric field.

The invention relates to a test method of steel, in particular to a test method of a micro amount of arsenic or antimony in steel. The test method is based on a principle of a flow injection-hydride generation-atomic absorption spectroscopic methodology, and experiments are determined in a flow-injection sample-injection mode. The method comprises the following steps: a test solution is reduced bya thiourea-ascorbic acid mixed solution and a hydrochloric acid solution to convert arsenic (V) into arsenic (III), and convert antimony (V) into antimony (III); the test solution reacts with a potassium borohydride solution under a carrier band of a carrier solution to generate a great amount of nascent oxygen which reacts with the arsenic (III) or the antimony (III) to generate gaseous AsH3 orSbH3; the AsH3 or the SbH3 is led into a specially-designed quartz tube by high-purity argon gas as carrier gas and is atomized into ground-state atomic vapor; ground-state electrons which are on theoutermost layer of the atom are excited by the light energy of a light source of a hollow cathode lamp to transit to a high energy level; and the amount of abortion light intensity is directly proportional to the concentration of the atom. Accordingly, the arsenic or antimony content in the test solution can be quantitatively analyzed.

The invention discloses an atomic vapor generation method and device based on dielectric barrier discharge. The method comprises subjecting a mixture of inert gas and hydrogen gas to dielectric barrier discharge under the action of alternating electric field to generate plasma; and allowing a to-be-measured element in a to-be-measured sample to form atomic vapor under the action of the plasma. The inventive device adopts dielectric barrier discharge in which a large number of free radicals and quasi-molecules, such as H, having a very active chemical property are generated, and the free radicals and the quasi-molecules easily react with to-be-measured atoms or other free radicals to generate hydride vapor, so as to effectively separate from the matrix and enter a to-be-measured region; matrix interference brought in by a sample pre-treatment process is reduced to therefore improve the signal to noise ratio of the analyzer and reduce the instrument detection limit, and the device is simple and easy to operate; and dielectric barrier discharge can be realized under the atmospheric pressure, so as to realize small volume, low energy consumption and low gas temperature.

The invention discloses a cold atom interferometry principle-based inertia measuring device. The cold atom interferometry principle-based inertia measuring device comprises three inertia measuring units, a Raman laser, and a light dividing device with adjustable splitting ratio; each inertia measuring unit comprises a single-mode narrow linewidth laser, an interferometic cavity, a optical fiber beam splitter, four acoustic optical modulators (AOM), and one electrooptical modulator (EOM); the interferometic cavities are filled with rubidium atomic vapor; Raman laser light send by the Raman laser can be divided into three beams of Raman laser light via the light dividing device with adjustable splitting ratio, and the three beams of Raman laser light are send to the three inertia measuring units; wherein the incidence directions of the three beams of Raman laser light are orthogonal to each other. According to the cold atom interferometry principle-based inertia measuring device, a reasonable structure scheme is adopted; three atom interferometers are arranged in a pyramid mode, so that sensitive acceleration directions of the atom interferometers are orthogonal to each other, and sensitive angular velocity directions are orthogonal to each other. One set of laser system is shared by the three atom interferometers, so that synchronization of atom interference process is realized, and the atom interferometer-based inertia measuring units are sensitive to inertial parameters with six degrees of freedom simultaneously.

An excited state atomic line filter. The present invention solves the problem of lack of ground state resonant lines in at wavelengths substantially longer than those of visible light. Atomic line filters of the Faraday or Voigt crossed polarizer type are provided in which alkali metal atomic vapor in a vapor cell is excited with a pump beam to an intermediate excited state where a resonant absorption line, at a desired wavelength, is available. A magnetic field is applied to the cell producing a polarization rotation for polarized light at wavelengths near the resonant absorption lines. Thus all light is blocked by the cross polarizers except light near one of the spaced apart resonant lines. However, the polarization of light at certain wavelengths near the resonant is rotated in the cell and therefore passes through the output polarizer.

The invention discloses a self-tuning method for temperature control parameters of a passive CPT (Coherent Population Trapping) atomic clock. The method comprises the following steps of: acquiring digital temperature information of an atomic vapor bubble and a VCSEL (Vertical Cavity Surface Emitting Laser); carrying out PID (Proportion Integration Differentiation) operations on difference values between the digital temperature information which is subjected to filtering processing and digital quantities corresponding to temperature set points; carrying out PWM (Pulse Width Modulation) and delta-sigma modulation on a result obtained after the PID operations, and then, outputting the result to a peripheral circuit for heating and refrigerating; and self-tuning temperature control PID parameters of the atomic vapor bubble and the VCSEL. The invention further discloses a self-tuning device for the temperature control parameters of the passive CPT atomic clock. The method and the device have the advantages that the full-duplex communication between the passive CPT atomic clock and an upper computer is realized, the self-tuning of the temperature control PID parameters can be carried out, the accuracy of regulation of temperature control is improved, the power consumption is low, and the accuracy is high.

The invention belongs to the technical field of optical space communication, particularly relates to an ultra narrow band excited state faraday anomalous dispersion atom filter of a communication band, and aims at effectively improving the pumping efficiency of the excited state atom filter and overcoming the problems of complicated light path, high demands on an environmental condition, poor adaptability and low practicability caused by a pump laser frequency stabilization module. An external frequency stabilization module is removed by the filter while an Rb atomic vapor absorption peak inside the filter is utilized as a frequency standard. Thus, the ultra narrow band excited state faraday anomalous dispersion atom filter is simpler in structure, better in work stability and higher in efficiency. The scheme is combined with a generation principle of a multi-transition absorption band, and the targeted frequency stabilization mod is adopted, so that a good pumping effect can be obtained.

An atomic magnetometer includes a vapor cell, one or more pumping lasers, a probe laser, and a sensor. The one or more pumping lasers are disposed to direct one or more laser beams though the vapor cell to interact with atoms of an atomic vapor in the vapor cell. The atomic vapor periodically absorbs light of alternating circular polarization from the one or more laser beams. The probe laser is disposed to direct polarized light to pass through the vapor cell. The sensor is disposed to intersect the polarized light from the probe laser after passing through the vapor cell.

The invention discloses a preparation method for a double-chamber MEMS atomic vapor cell. The method provided by the invention has the advantages that an MEMS atomic vapor cell alkali metal filling method, in which bonding is carried out prior to filling, is provided, and the traditional glass vapor cell alkali metal filling method is combined with the MEMS atomic vapor cell preparation technique, so that the performance of the MEMS atomic vapor cell is improved; the preparation method is a beneficial supplement to novel MEMS atomic vapor cell preparation methods, and an exploration of vapor cell preparation methods; the preparation cost for the MEMS atomic vapor cell is reduced; the alkali metal purity in the MEMS atomic vapor cell and the performance of the vapor cell are improved; and batch production can be achieved.

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 relates to a preparation method of a stannic oxide-titanium dioxide core-shell nano-structure. The preparation method comprises the following steps of: preparing a stannic oxide nano-wire by a chemical vapor deposition method, and coating a titanium dioxide nano-structure of rutile phase on the surface of the stannic oxide nano-wire layer by layer by an atomic vapor deposition method. According to the preparation method, firstly, the stannic oxide nano-wire is grown on the surface of a silicon wafer which is sprayed with nano-gold particles by a chemical vapor deposition device; secondly, hydroxyl group is attached on the surface of the stannic oxide nano-wire by an ultraviolet treatment device; and finally, the silicon wafer grown with the stannic oxide nano-wire is put into an atomic layer deposition device, and alternately and circularly depositing the titanium dioxide nano-structure and the hydroxyl group by the atomic vapor deposition method, so that the stannic oxide-titanium dioxide core-shell nano-structure can be formed. The preparation method has the advantages that the operation flow is simple, the core-shell structure is accurate and controllable in the thickness and even in size distribution, etc.

The invention discloses a coherent population trapping (CPT) rubidium atom magnetometer. The CPT rubidium atom magnetometer comprises a vertical cavity surface emitting laser (VCSEL), a collimating lens, a gamma / 4 wave plate, an indium tin oxide (ITO) heater, an atomic vapor cell, a magnetic shielding barrel, a photovoltaic detector, a data collecting module, a temperature control module, an uppercomputer and a circuit control module. Under the action of a magnetic field in parallel to a light path, CPT signals generated by a modulating laser which passes through the rubidium atomic vapor cell are measured, and then according to the relation between the frequency difference and the magnetic field intensity of the CPT signals, precise measurement of the magnetic field is realized. The CPTrubidium atom magnetometer reduces the interference of external tangled magnetic fields, improves the stability of the output CPT signals, has the advantages that the sensitivity is high, the power consumption is low, the size is small and the like, and has significant application value in the aspects of biomedicine, geophysics, quantum frequency standard, military detection and the like.

The invention discloses a nuclear magnetic resonance gyroscope device for improving atomic polarization uniformity. The device comprises an atomic vapor chamber, a non-magnetic heating device, a magnetic shielding device, a three-dimensional magnetic field coil, a pump light laser, a first polarizer, a first lambda / 4 wave plate, a second lambda / 4 wave plate, a first reflector, a probe light laser,a second reflector, an acousto-optic modulator, a diaphragm, a second polarizer, a lambda / 2 wave plate, a Wallstone prism, a differential photodetector, a first lock-in amplifier, a second lock-in amplifier, and a computer. With the device of the invention adopted, the problem of the non-uniformity of atomic polarization in a nuclear magnetic resonance gyroscope can be solved, and a guarantee isprovided for improving the detection sensitivity of the nuclear magnetic resonance gyroscope.

The present invention provides a method and apparatus for making atomic clocks or atomic magnetometers as self-modulated laser systems based on the physics of push-pull optical pumping. An atomic vapor cell is required to be in the laser cavity. With proper conditions, spontaneous push-pull optical pumping can occur inside the laser cavity. This causes the laser beam to be modulated at hyperfine-resonance frequency. With a fast photodetector, the modulated laser signal can be converted into the electrical signal, which serves as the atomic clock ticking signal or magnetometer signal. The self-modulated laser system does not use any local oscillator and the microwave circuit to lock the oscillator frequency to the hyperfine-resonance frequency, and therefore can consume less power and become more compact than conventional systems. This invention will benefit applications of time measurements and magnetic-field measurements.

The invention belongs to the technical field of space optical communication and particularly relates to an excited state Faraday anomalous dispersion atomic filtering method for an ultra narrow band of a communication waveband. In order to effectively increase the pumping efficiency of an excited state atomic optical filter and overcome the defects of complex optical path, high environment condition requirement, poor adaptability and low practicability caused by a pumped laser frequency stabilizing module, the operation step for externally placing a frequency stabilizing module is omitted while Rb atomic vapor absorption waves inside an optical filter are used as frequency standards, so that the method is relatively simple in operation process, relatively good in working stability and relatively high in efficiency; moreover, the scheme is combined with a multi-transition absorption band generating principle, and a frequency stabilizing way with rather strong pertinence is adopted, so that a good pumping effect can be obtained.