Patents
Literature
693 results about "Acousto-optic modulator" patented technology
Efficacy Topic
Property
Owner
Technical Advancement
Application Domain
Technology Topic
Technology Field Word
Patent Country/Region
Patent Type
Patent Status
Application Year
Inventor
An acousto-optic modulator (AOM), also called a Bragg cell, uses the acousto-optic effect to diffract and shift the frequency of light using sound waves (usually at radio-frequency). They are used in lasers for Q-switching, telecommunications for signal modulation, and in spectroscopy for frequency control. A piezoelectric transducer is attached to a material such as glass. An oscillating electric signal drives the transducer to vibrate, which creates sound waves in the material. These can be thought of as moving periodic planes of expansion and compression that change the index of refraction. Incoming light scatters (see Brillouin scattering) off the resulting periodic index modulation and interference occurs similar to Bragg diffraction. The interaction can be thought of as a three-wave mixing process resulting in Sum-frequency generation or Difference-frequency generation between phonons and photons.
Aspects of basic OCT engine technologies for high speed optical coherence tomography and light source and other improvements in optical coherence tomography
InactiveUS7061622B2Scattering properties measurementsDiagnostic recording/measuringGratingAcousto-optics
An optical coherence tomography (OCT) system including an interferometer provides illuminating light along a first optical path to a sample and an optical delay line and collects light from the sample along a second optical path remitted at several scattering angles to a detector. In one embodiment, illuminating light is directed along a number of incident light paths through a focusing lens to a sample. The light paths and focusing lens are related to the sample and to both the incident light source and the detector. In another embodiment, a focusing system directs light to a location in the sample. A transmission grating or acousto-optic modulator directs light from the sample at an angle representative of the wavelength of the incident light on the transmission grating or acousto-optic modulator.
Owner:UNIVERSITY HOSPITALS OF CLEVELAND CLEVELAND +1
COTDR (coherent detection based optical time-domain reflectometry) fused long-distance coherent detection brilouin optical time-domain analyzer
InactiveCN102759371AImprove signal-to-noise ratioImprove dynamic rangeThermometers using physical/chemical changesUsing optical meansSpectrum analyzerLine width
The invention discloses a COTDR (coherent detection based optical time-domain reflectometry) fused long-distance coherent detection brilouin optical time-domain analyzer which comprises a narrow-linewidth laser, two couplings, a microwave signal source, an electro-optic modulator, an isolator, a long-distance sensing optical fiber, an optical circulator, a 3 db coupling, a pulse modulator, an Er-doped fiber amplifier, a scrambler, a pulse signal generator, a balancing photoelectric detector, an electrical frequency spectrum analyzer, a data processing module and an acousto-optic modulator. According to the invention, the signal-to-noise ratio of BOTDA (brilouin optical time domain analysis) is improved by using a coherent detection method, a non-local effect of a BOTDA system is reduced in a double-sideband detection mode, and the sensing distance is more than 70 km under the condition of no light amplification such as raman; and according to the invention, the COTDR is fused to a coherent detection based BOTDA system, and the system can run in a breakpoint testing mode, so that the defect that the traditional BOTDA can not run when a sensing fiber has breakpoints and can not carry out positioning on breakpoints is effectively overcome, thereby enhancing the adaptability and practicability of the sensing system.
Owner:NANJING UNIV
Optical pulse sources
ActiveUS20090097512A1Low in pulse energyIncrease light intensityLaser detailsMaterial analysis by optical meansFundamental frequencyLength wave
An optical pulse source comprising a DPSS pump laser, a photonic crystal fiber (PCF), and acousto-optic modulator (AOM) gating device is disclosed. The pump pulses are coupled through lenses to the AOM gating device, which is synchronized to the pump laser and is operable to gate the pump pulses to a reduced repetition rate Rr=Rf / N, where Rf is the pump laser fundamental frequency. The pulses from the AOM are injected via optics into the PCF. Propagation through the PCF causes the pulses to broaden spectrally to produce optical supercontinuum pulses. An optical pulse source that further includes an acousto-optical tunable filter (AOTF) operable to convert the optical supercontinuum pulses into wavelength variable output pulses is also provided. A method of scaling the energy of the optical supercontinuum pulses is also disclosed.
Owner:NKT PHOTONICS
On-the-fly laser beam path error correction for specimen target location processing
InactiveUS7245412B2Improve manufacturabilityEliminate settling timeSemiconductor/solid-state device detailsSolid-state devicesOptical mountLight beam
A laser-based workpiece processing system includes sensors connected to a sensor controller that converts sensor signals into focused spot motion commands for actuating a beam steering device, such as a two-axis steering mirror. The sensors may include a beam position sensor for correcting errors detected in the optical path, such as thermally-induced beam wandering in response to laser or acousto-optic modulator pointing stability, or optical mount dynamics.
Owner:ELECTRO SCI IND INC
Optical fiber transmission system with polarization multiplexing to reduce stimulated brillouin scattering
InactiveUS6850712B1Lower Level RequirementsReduce impactLaser detailsPolarisation multiplex systemsLine widthTime delays
A technique for suppressing stimulated Brillouin scattering SBS along an optical fiber signal path utilizes polarization modulation at the transmitter to split the launched power into orthogonal polarization states. By reducing the power along each polarization, SBS will be reduced. Linewidth broadening of the optical source is achieved by introducing: (1) a incoherence between the polarization states (using a time delay along the signal path of one polarization state); and (2) a frequency shift between the polarization states (using an acousto-optic modulator along the signal path of the remaining polarization state).
Owner:ALCATEL-LUCENT USA INC +1
Laser intra-cavity electronic wavelength tuner
An apparatus for adjusting the wavelength of a laser capable of lasing at multiple wavelengths by using a single acousto-optical modulator and a pair of optical reflectors inside a laser cavity. By adjusting the frequency and amplitude of the radio-frequency source to the acousto-optical modulator, undesired wavelengths are suppressed in the laser cavity, leaving appreciable gain only at the desired wavelength.
Owner:THE BOEING CO
Magnetic Field Measuring Apparatus
ActiveUS20160313417A1Stable signalLaser detailsLaser optical resonator constructionOptical pumpingAcousto-optics
The present invention addresses the problem of stabilizing signals in magnetic field measurement using optical pumping. In order to solve the problem, disclosed is a light source apparatus (10) that is characterized in having: a light intensity fluctuation detection circuit (130) that detects intensity fluctuation of light outputted from a laser output unit (11); and an acousto-optic modulator (121) that corrects light intensity on the basis of light intensity fluctuation detected by means of the light intensity fluctuation detection circuit (130) such that the light intensity is constant Furthermore, a magnetic field measuring apparatus of the present invention is characterized in having: one sensor unit that passes therethrough light outputted from a light source unit: and a signal control processor that eliminates the light intensity fluctuation on the basis of two lights passed through the sensor unit.
Owner:HITACHI LTD
Active coherence reduction for interferometer interrogation
ActiveUS20050078316A1Broadened optical spectrumEvenly distributedUsing optical meansConverting sensor output opticallyControl mannerInterferometric sensor
Methods and apparatus for reducing the coherence of an optical signal that is used to interrogate optical interferometric sensors are disclosed. The optical field phasor of the interrogation source is modulated in a controlled manner to produce a broadened optical source power spectrum at the output of the source unit. The output from the source unit is launched into an optical sensor network, comprising a multiple of optical pathways from its input to the detection unit, where pairs of optical pathways form sensor interferometers. A compensating interferometer with delay difference similar to the sensor delay difference may be arranged in a serially coupled manner with the optical sensor network, either before or after the network. The optical output power from the source unit may either be continuous or pulsed with a pulse duration similar to the sensor delay. The coherence modulation may be performed through direct modulation of the source or through external modulation of the light with piezoelectric ring modulator, a Lithium niobate phase or intensity modulator, or an acoustooptic modulator.
Owner:OPTOPLAN
Optical synchronization system for femtosecond x-ray sources
ActiveUS20080043784A1Compensation differenceLaser detailsElectromagnetic transmissionMode locked fiber laserX-ray
Femtosecond pump / probe experiments using short X-Ray and optical pulses require precise synchronization between 100 meter-10 km separated lasers in a various experiments. For stabilization in the hundred femtosecond range a CW laser is amplitude modulated at 1-10 GHz, the signal retroreflected from the far end, and the relative phase used to correct the transit time with various implementations. For the sub-10 fsec range the laser frequency itself is upshifted 55 MHz with an acousto-optical modulator, retroreflected, upshifted again and phase compared at the sending end to a 110 MHz reference. Initial experiments indicate less than 1 fsec timing jitter. To lock lasers in the sub-10 fs range two single-frequency lasers separated by several teraHertz will be lock to a master modelocked fiber laser, transmit the two frequencies over fiber, and lock two comb lines of a slave laser to these frequencies, thus synchronizing the two modelocked laser envelopes.
Owner:RGT UNIV OF CALIFORNIA
Optical fiber distributed disturbance sensor
InactiveCN102506912AIncrease sensing distanceIncrease optical powerConverting sensor output opticallyContinuous lightAcousto-optics
The invention discloses an optical fiber distributed disturbance sensor which comprises an optical fiber laser, a bidirectional distributed Raman amplification unit and a photoelectric detection and signal processing unit, wherein an output end of the optical fiber laser is connected with a first coupler; two output ends of the first coupler are respectively connected with an acoustic optical modulator and a third coupler; the bidirectional distributed Raman amplification unit is connected with the acoustic optical modulator by a first circulator and is connected with the third coupler by the first circulator; the photoelectric detection and signal processing unit is connected with the third coupler and used for receiving an interference-enhanced optical signal in the third coupler, converting the optical signal into an electric signal and carrying out subsequent data processing. In the optical fiber distributed disturbance sensor, the back scattering light intensity and the signal-to-noise ratio of the tail end of the optical fiber can be improved by the bidirectional distributed Raman amplification structure so as to improve the sensing distance of the optical fiber distributed disturbance sensor; and the light power received by a detector can be improved through the interference of a part of continuous light output by a light source and the back scattering light, so as to improve the signal-to-noise ratio of the system. The sensor is a combination of conventional photoelectric devices, has a simple structure and is easy to realize.
Owner:BEIHANG UNIV
Device for measuring linewidth of narrow linewidth laser based on optical fiber time-delay self heterodyne method as well as method for measuring thereof
InactiveCN101201243ARealize high-precision testingReduce volumeUsing optical meansThree levelSpectrum analyzer
The invention discloses a device of measuring the line-width of a laser with narrow line-width and a method of measuring the line-width based on a optical fiber delay self-heterodyne method; in the hardware device, an optical fiber delay line is connected between a first and a second couplers; an acousto-optic modulator is connected between the first and the second couplers; the measured laser is connected to the input of the first coupler, and a photoelectric detector is connected to the output of the second coupler; the photoelectric detector is connected with a spectrum analyzer. In the line-width measurement, simulation models of the line-width triangle v of the laser and the spectrum-width triangle f of the photoelectric current heterodyne signal are built in the frequency shift delay self-heterodyne methodology, and the function relation between the line-width triangle v of the laser and the spectrum-width triangle f of the photoelectric current heterodyne signal is obtained fitting of the three-level proportion function model. The invention presents that with the short optical fiber delay self-heterodyne method, the device can eliminate the deficiency of greatly reduced measuring precision because of not enough delayed time in the delay self-heterodyne method when the length of the delay optical fiber is less than 6 times coherence length of the laser, so as to provide an effective method of precisely measuring the line-width of the laser with narrow line-width in projects.
Owner:BEIHANG UNIV
RF phase modulation technique for performing acousto-optic intensity modulation of an optical wavefront
An acousto-optic modulator includes an acousto-optic bulk medium and transducer attached to the acousto-optic bulk medium and formed as a linear array of electrodes. A transducer driver is connected to each electrode and is coherently phase driven to alter the angular momentum distribution of an acoustic field and alternately allow and inhibit phase matching between the optical and acoustic field and produce a desired intensity modulation of an optical wavefront.
Owner:HARRIS CORP
Energy limiter for amplitude modulated RF waveforms
InactiveUS6870658B2Low costPermit useAmplifier modifications to reduce temperature/voltage variationAmplifier modifications to raise efficiencyPower controllerEnergy supply
An RF power controller arrangement prevents excessive RF power-based thermal loading of an RF signal processing device, such an as acousto-optic modulator, by controllably constraining the product of the average on-duration of a baseband modulation signal and RF input power to realize no more than a prescribed value of RF energy supplied to the modulator.
Owner:NORTH SOUTH HLDG
High-repetition-rate femtosecond regenerative amplification system
Provided is a high-repetition-rate femtosecond regenerative amplification system. The regenerative amplification system includes: a laser oscillator emitting pulses; a stretcher stretching the pulses with negative dispersion; a regenerative amplifier amplifying the pulses, the regenerative amplifier comprising an acousto-optic modulator for pulse switching, a pulsed pump laser for pumping a gain medium, a resonator for reciprocating the pulses between a plurality of mirrors, and at least one chirped mirror for providing negative dispersion; and a glass compressor compressing the pulses. Accordingly, the 100 kHz-class high-repetition-rate femtosecond regenerative amplification system can produce an output energy of tens of μJ, higher than a few μJ provided by a conventional system.
Owner:GWANGJU INST OF SCI & TECH
Laser cavity outer power stabilizing device and locking method
ActiveCN102141692AImprove long-term stabilityReduce design difficultyNon-linear opticsOptical elementsBeam splitterEngineering
The invention discloses a laser cavity outer power stabilizing device and a laser cavity outer power stabilizing method. Reference signals are taken out from a laser system through an unpolarized beam splitter, and an acoustic optical modulator is used as an executor to form a negative feedback loop so as to realize stabilization of optical power. A 1 / 2 wave plate and a polarizing beam splitter are inserted into a light path to perform polarization and purification, and polarization drift of a laser system can be converted into power fluctuation, so that the splitting ratio of the unpolarized beam splitter is constant and the long-term stability of the optical power is improved; and the acoustic optical modulator is used as an execution element, and the amplitude modulation end of a driver of the acoustic optical modulator can be modulated by using low voltage, so that the noise of a control circuit can be remarkably reduced, the short-term stability of high optical power can be realized, and meanwhile, the stability of the optical power in a large dynamic range can be realized.
Owner:杭州昕磁科技有限公司 +1
Rubidium atomic magnetometer and magnetic field measuring method thereof
ActiveCN107015172ALarge measuring rangeMagnetic field sampling rate adjustableMagnetic field measurement using magneto-optic devicesData acquisitionWork flow
The invention discloses a rubidium atomic magnetometer and a magnetic field measuring method. Based on the principle of nonlinear magneto-optic rotation, and through combination of timing control and tracking type frequency locking control, the atomic magnetometer achieves a large dynamic measurement range, high magnetic field sampling rate and high sensitivity. A DSP timing control module controls on-off of an acousto-optic modulator and a radio-frequency signal source in the physical part of the rubidium atomic magnetometer according to timing combination to adjust the magnetic field sampling rate N. The DSP timing control module further controls acquisition triggering of a data acquisition card. A calculation unit gets the Larmor precession frequency (f) through fast Fourier transform with use of a received rubidium atom Larmor precession free relaxation signal, and further calculates the value of an external magnetic field. The calculation unit selects a high magnetic field sampling rate module or a low magnetic field sampling rate module before measurement according to the pre-judged dynamic range of a to-be-measured magnetic field, and sets whether a tracking type frequency locking work mode is used when the low magnetic field sampling rate module is selected. In the working process, data is acquired and processed, and the value of the magnetic field is output.
Owner:LANZHOU INST OF PHYSICS CHINESE ACADEMY OF SPACE TECH
Apparatus and method for locking DDS acousto-optic modulation wavelength
InactiveCN101442179ANarrow output laser linewidthSufficient error signal amplitudeLaser detailsFrequency stabilizationLine width
The invention relates to a DDS acoustooptic modulation wavelength locking device and a wavelength locking method. The wavelength locking method can be realized by arranging an acoustooptic modulator and a convex lens on the basis of modulating a laser cavity in the prior art. The DDS acoustooptic modulation wavelength locking device has a concise light path, is easy to adjust, and can obviously narrow the laser linewidth and acquire enough error signal amplitude to realize stable frequency locking; due to adoption of the acoustooptic modulator, the stability of locked frequency is good and superior to that of a general voltage controlled oscillator; and due to adoption of digital frequency modulation, the DDS acoustooptic modulation wavelength locking device is flexible and convenient, and is convenient to cooperate with a digital industrial control device.
Owner:ZHEJIANG UNIV
Compact acousto-optical modulator
InactiveUS7006274B1Eliminate tuningColor television detailsNon-linear opticsGreen laserAcousto-optics
A lightweight, compact image projection module, especially for mounting in a housing having a light-transmissive window, is operative for causing selected pixels in a raster pattern to be illuminated to produce an image of high resolution of VGA quality in color. A compact acousto-optical modulator is used to modulate a green laser beam used to produce the image.
Owner:MICROVISION
Method and apparatus for article inspection including speckle reduction
InactiveUS20050128473A1Small and simpleConvenient in introducing large optical path length variationSemiconductor/solid-state device testing/measurementScattering properties measurementsGratingOptical pathlength
A method and apparatus for reducing speckle during inspection of articles used in the manufacture of semiconductor devices, including wafers, masks, photomasks, and reticles. The coherence of a light beam output by a coherent light source, such as a pulsed laser, is reduced by disposing elements in a light path. Examples of such elements include optical fiber bundles; optical light guides; optical gratings; an integrating sphere; and an acousto-optic modulator. These various elements may be combined as desired, such that light beams output by the element combinations have optical path length differences that are greater than a coherence length of the light beam output by the coherent light source.
Owner:APPLIED MATERIALS INC
On-the fly laser beam path dithering for enhancing throughput
InactiveUS8497450B2Improve manufacturabilityEliminate settling timeSemiconductor/solid-state device manufacturingLaser beam welding apparatusOptical mountLight beam
A laser-based workpiece processing system includes sensors connected to a sensor controller that converts sensor signals into focused spot motion commands for actuating a beam steering device, such as a two-axis steering mirror. The sensors may include a beam position sensor for correcting errors detected in the optical path, such as thermally-induced beam wandering in response to laser or acousto-optic modulator pointing stability, or optical mount dynamics.
Owner:ELECTRO SCI IND INC
Double-beam multi-functional z scanning optical non-linear measuring device and method
InactiveCN101806723AEasy to switchContinuously adjustable laser powerPhase-affecting property measurementsUsing optical meansRefractive indexCcd camera
The invention discloses a double-beam multi-functional z scanning optical non-linear measuring device and a double-beam multi-functional z scanning optical non-linear measuring device method. The device uses two light sources and can conveniently switch the light sources; an adjustable attenuation slice is adopted, so laser power is continuously adjustable from 0 and 100 percent; an acoustic optical modulator and a signal generator are adopted, so the pulse width and pulse period of emergent laser are adjustable; and transmission open hole and transmission closed hole data of a sample can be measured and reflecting open hole and transmission open hole data of the sample can also be measured. The device and the method not only can measure nonlinear absorption coefficient and nonlinear refractive index of a transparent sample, but also can measure nonlinear refractive index of a nontransparent sample; and a cold light source serving as an illumination light source is added into the device, a CCD camera is used for observing surface appearance of the sample and an optical filter is used for filtering the effect of the laser, so the measuring accuracy and correctness of the nonlinear absorption coefficient and nonlinear refractive index of the transparent sample and a partially transparent sample are enhanced.
Owner:SHANGHAI INST OF OPTICS & FINE MECHANICS CHINESE ACAD OF SCI
System and method for multi-pulse laser processing
InactiveUS20080164240A1Avoid problemsGuaranteed uptimeSemiconductor/solid-state device detailsSolid-state devicesLaser processingOptoelectronics
Laser pulses are selected from a group of closely spaced laser pulses with an optical modulator by adjusting pulse timing relative to an impingement interval. An adjusted pulse is moved from an impingement interval to a non-impingement interval and is blocked. The blocked laser source is stabilized by running nearly continuously. Pulse selection with multiple laser sources is achieved with a single acousto-optic modulator.
Owner:ELECTRO SCI IND INC
Intensity distribution type demodulation system and distribution type sensing optical fiber
ActiveCN104181635AAvoid Splice LossIncrease capacityCladded optical fibreOptical waveguide light guideGratingAcousto-optics
A distribution type sensing optical fiber is characterized in that thousands of fiber gratings with ultra-low reflectance are carved on a common single-mode fiber, so that the common single-mode fiber and the fiber gratings are integrated; the reflectance R of the fiber gratings is set to be 0.1-1%, and accordingly multi-path reflection is effectively lowered. An intensity distribution type demodulation system comprises a distribution type feedback semiconductor laser device, an acousto-optic modulator, a circulator, a coupler, the distribution type sensing optical fiber, a photoelectric detector and an intensity modulation device. The distribution type feedback semiconductor laser device sends out continuous laser into the acousto-optic modulator, the laser is modulated into pulse laser with the pulse width of W, the pulse laser enters the circulator and sequentially travels through a first grating, a second grating, a third grating to the Nth grating on the distribution type sensing optical fiber, reflected light enters an unbalance interferometer from the C3 end of the circulator for interference, interference light output by the unbalance interferometer enters the photoelectric detector, and the photoelectric detector outputs electric signals to an intensity demodulation device.
Owner:LASER RES INST OF SHANDONG ACAD OF SCI
On-the-fly laser beam path dithering for enhancing throughput
InactiveUS20080093349A1Elimination of cross-axis settling timeImprove throughputSemiconductor/solid-state device manufacturingLaser beam welding apparatusOptical mountLight beam
A laser-based workpiece processing system includes sensors connected to a sensor controller that converts sensor signals into focused spot motion commands for actuating a beam steering device, such as a two-axis steering mirror. The sensors may include a beam position sensor for correcting errors detected in the optical path, such as thermally-induced beam wandering in response to laser or acousto-optic modulator pointing stability, or optical mount dynamics.
Owner:ELECTRO SCI IND INC
Self-excited atomic magnetic sensor for liquid crystal phase compensation and magnetic field measurement method
ActiveCN109188316AQuick responseAvoid phase shiftMagnetic field measurement using magneto-optic devicesSelf excitedClosed loop
The invention discloses a self-excited atomic magnetic sensor for liquid crystal phase compensation and a magnetic field measurement method, which are used for a magnetometer. The self-excited atomicmagnetic sensor comprises a pumping light path perpendicular to the direction of the magnetic field, a probe light path along the direction of the magnetic field, and a circuit closed loop. The pumping light path sequentially comprises an atomic air chamber, a first polarizer, an acousto-optic modulator, and a laser. The probe light path sequentially comprises a photoelectric detector, an atomic air chamber in the pumping light path, a second wave plate1 / 4, a liquid crystal, a first wave plate1 / 4, a second polarizer, and a laser. The closed loop portion of the circuit comprises a photoelectricdetector, an amplifying comparator, a power driver, an acousto-optic modulator, and a counter. According to the liquid crystal phase compensation scheme, a phase shift caused by a circuit coil can beavoided, a phase shift of a larger range magnetic field can be achieved, and the problem that the circuit is unfavorable in the phase shift is solved by combining a light intensity modulation magnetometer and a self-excited magnetometer, the response speed is high, the liquid crystal phase compensation scheme is suitable for the various atomics, and the application value is high.
Owner:PEKING UNIV
Femtosecond laser carrier envelope offset frequency lock system based on heterodyne interferometric method
The invention relates to a femtosecond laser carrier envelope offset frequency lock system based on a heterodyne interferometric method. The system is characterized by comprising a femtosecond laser light source system, an acousto-optic modulator, a controllable optical path retardation device, a light splitting prism, a first photoelectric detector, a phase lock amplifier, a phase difference voltage conversion device and a PID controller. Heterodyne interferometry can be conducted on first-level phase-shift diffraction light modulated by the acousto-optic modulator and zero-level diffraction light which is not modulated, and after mixing of interference signals with different wavelengths, direct-current level lock pulse envelope alignment is achieved; optical frequency comb envelope offset frequency is locked by means of interference signal phase, the linear process does not exist, high non-linear optical fibers, frequency doubling crystals and the like are not needed, and the system is simple in structure and low in requirement for laser energy.
Owner:TSINGHUA UNIV
Acoustic optical modulator-based high-stability laser frequency scanning device
ActiveCN103746285AIncrease flexibilityImprove stabilityLaser detailsNon-linear opticsDiffraction orderAcousto-optics
The invention provides an acoustic optical modulator-based high-stability laser frequency scanning device. Laser passes through two coaxial diaphragms and is divided into two paths by a polarization beam splitter prism; one path of output passes through a quarter-wave plate, a No. 3 diaphragm and a No. 1 lens which are coaxial with one another, and enters a No. 1 acoustic optical modulator; diffraction-order laser light passes through a No. 4 diaphragm and a No. 2 lens which are coaxial with each other, and is reflected by a zero-degree high reflective mirror along an original path; the other path of output passes through two 45-degree planar reflecting mirrors and is regulated into parallel light through an optical fiber of which the two ends are matched with optical fiber matching heads, and the parallel light enters a No. 2 acoustic optical modulator through a No. 1 glass flat plate and a No. 3 lens in sequence; diffracted light enters a No. 2 glass flat plate through a No. 5 diaphragm and a No. 4 lens. By adopting the device, the spatial stability and power stability of laser light can be ensured at the same time.
Owner:NAT TIME SERVICE CENT CHINESE ACAD OF SCI
Dual-wavelength superheterodyne-interference wide-range high-precision real-time displacement measuring system and method
ActiveCN107192336ALarge rangeImprove real-time performanceUsing optical meansSignal processing circuitsPolarizer
The invention discloses a dual-wavelength superheterodyne-interference wide-range high-precision real-time displacement measuring system and method. The system is composed of two lasers between which the wavelength difference is deltalambda, three polarization splitting prisms, four splitting prisms, two acousto-optic modulators, four 1 / 4 waveplates, five planar mirrors, three Polaroids, a super-narrowband filter plate, two large-bandwidth transimpedance photoelectric detectors, two low-bandwidth high-sensitivity photoelectric detectors, a reference reflector, a measured reflector, a signal processing circuit and a host computer. According to the invention, a synthesized wavelength interference signal generated by dual wavelengths is used to improve the measuring range of the system, so that the measuring range of the system is greater than the range of single-wavelength interference; a superheterodyne interference method is used to demodulate and filter output signals, the phase of the synthesis wavelength can be measured directly, and real-time measurement is realized; and the super-narrowband filter plate is used to collect single-wavelength interference signals, and the precision of single-wavelength interference measurement is ensured while the measuring range is widened.
Owner:ZHEJIANG UNIV
Collinear femto-second laser polarized pump detecting system
ActiveCN101446687AGuaranteed spatial coherenceAvoid problems adjusting beam directionLaser detailsMirrorsRotary stagePhotodetector
Owner:江苏中国科学院能源动力研究中心 +1
Digital enhanced interference-based high-sensitivity quasi-distributed fiber bragg grating vibration sensor
InactiveCN105157812ASuppress noiseImprove signal-to-noise ratioSubsonic/sonic/ultrasonic wave measurementUsing wave/particle radiation meansFiber couplerGrating
The invention discloses a digital enhanced interference-based high-sensitivity quasi-distributed fiber bragg grating vibration sensor, which comprises a narrow linewidth laser, a first fiber coupler, an electro-optic modulator, an acousto-optic modulator, a circulator, a weak reflection fiber bragg grating array, a second fiber coupler, a double-balanced detector, an arbitrary waveform generator, an electrical amplifier, n electrical delayers, n multipliers and a phase demodulator, wherein the output port of the narrow linewidth laser is connected with the input port of the first fiber coupler; the first output port of the first fiber coupler is connected with the light signal input end of the electro-optic modulator; the output port of the electro-optic modulator is connected with the light signal input port of the acousto-optic modulator; the light signal output port of the acousto-optic modulator is connected with the first port of the circulator; and the second port of the circulator is connected with the input port of the weak reflection fiber bragg grating array.
Owner:NANJING PIONEER AWARENESS INFORMATION TECH CO LTD
PatSnap Eureka turns technology decisions into work you can execute. Powered by our Innovation Knowledge Graph, it runs expert workflows across engineering, life sciences, materials and intellectual property. Get your review-ready output in minutes.
