322 results about "Optical isolator" patented technology

The invention relates to the technical field of laser ranging, in particular to a double-optical-comb hybrid ranging device which comprises a signal detection optical path system and a signal demodulation optical path system. Wherein the signal detection optical path system comprises a first optical frequency comb, a first optical isolator, a first optical collimator, a first beam splitter prism, a reference mirror, a Faraday rotator, a convergence mirror and a target reflector; the signal demodulation optical path system comprises a second optical frequency comb, a second optical isolator, a second optical collimator, a half-wave plate, a second beam splitter prism, a third beam splitter prism, a first polarization controller, a first photoelectric detector, a reflector, a polarization beam splitter prism, a second polarization controller and a second photoelectric detector. A third polarization controller; and a third photoelectric detector. According to the invention, three ranging technologies of asynchronous optical sampling ranging, multi-heterodyne interference ranging and synthetic wavelength ranging are fused, and the problem that a large ranging range and high ranging precision cannot be simultaneously considered in the ranging process is solved.

The invention discloses a method and a device for outputting large-energy picosecond pulse laser with external synchronization picosecond-level jitter. The device comprises a high-precision time sequence controller, a semiconductor picosecond pulse seed source, an optical isolator and a high-gain and high-stability regenerative amplifier. The semiconductor picosecond pulse seed source outputs low-energy picosecond-level (10-12J, pJ) and low-jitter picosecond-level (10-12s, ps) picosecond pulse seeds under the trigger of a time sequence controller of a high-precision external clock, the picosecond pulse seeds enter the high-gain high-stability regenerative amplifier through the optical isolator, and the high-gain high-stability regenerative amplifier outputs high-energy picosecond-level (10-12s, ps) picosecond pulse seeds under the control and adjustment of the high-precision time sequence controller. The picosecond pulse seed is locked to be regenerated and amplified in the regenerative amplifier, and the energy of the picosecond pulse seed with low energy and low jitter at a picofocus (pJ) level is amplified to uJ-mJ (10 <-6 > J-10 <-3 > J), so that low jitter and large energy output of laser pulses and trigger signals are realized, and application development of high-precision laser ranging, laser communication, time-frequency transmission and the like is effectively promoted.

The invention discloses a guided-mode resonance refractive index detection device and method based on a longitudinal gradient grating structure, and belongs to the technical field of optical sensing and imaging spectrum detection, the guided-mode resonance refractive index detection device comprises a light source, an optical isolator, a polarization controller, a collimation beam expander, a guided-mode resonance sensing chip, an image detector and a signal processing unit which are connected in sequence; the guided-mode resonance sensing chip is of a transmission type structure, the top of the guided-mode resonance sensing chip is provided with a strip-shaped nano structure which is consistent in period but longitudinally gradually changed, and an image detector is arranged below the guided-mode resonance sensing chip and used for receiving a transmission light signal penetrating through the guided-mode resonance sensing chip, generating a transmission light image and transmitting the transmission light image to the signal processing unit; and the signal processing unit is used for analyzing the transmitted light image and inverting the refractive index of the medium to be measured according to the structure mapping model. According to the invention, the longitudinal structure gradual change characteristic is introduced into the guided-mode resonance chip, so that the spatial distribution control of the monochromatic light resonance response position is realized, and finally the imaging refractive index sensing without an optical splitter is realized.

The utility model discloses a distributed sound wave sensing system for multi-frequency pulse modulation, and relates to the technical field of distributed sound wave sensing. The system comprises a narrow linewidth laser, an optical fiber coupler, a polarization-maintaining optical isolator, an acousto-optic modulator, a polarization-maintaining delay optical fiber, an erbium-doped optical fiber amplifier, a polarization-maintaining dense wavelength division multiplexer, an optical fiber circulator, an optical fiber Bragg grating, a piezoelectric transducer, a polarization controller, a photoelectric balance detector, a data acquisition card, an arbitrary waveform generator and the like. According to the utility model, the multi-frequency delay ring is utilized to carry out multi-frequency modulation, the frequency number of light waves is increased along with the circulation times of the light waves in the delay ring, and under the condition that the utilization of a large-bandwidth electro-optical modulator is not increased, the flexible modulation of the frequency is realized by utilizing a low-bandwidth acousto-optical modulator without being influenced by carrier frequency and sidebands of each order; the low-bandwidth acousto-optic modulator is used for frequency modulation in the multi-frequency delay ring, and compared with an electro-optical modulation or multi-acousto-optic / multi-light source modulation scheme, the modulation cost is effectively saved.

The present application relates to a kind of methods and applications of growing bismuth-doped rare-earth iron garnet BRIG crystal by guided mode pulling-top seed crystal method.For solving the problems of large internal stress, many defects, difficult to prepare thick film of single crystal in the current liquid phase epitaxy method of growing BRIG crystal;And the problems of long growth cycle, difficult to obtain seed crystal in top seed crystal method, the present application combines the fast growth of guided mode pulling crystal and the high-quality single crystal growth of top seed crystal method, and invents guided mode pulling-top seed crystal method to realize the fast growth of high-quality BRIG single crystal.First, the large-size doped rare-earth iron garnet crystal with high lattice matching and similar composition is quickly grown by guided mode pulling method, which is cut into centimeter-level seed crystal, and high-quality BRIG bulk single crystal is quickly grown by TSSG method.The crystal grown by this method has the advantages of small internal stress, less cracking, good uniformity, fast crystal growth, etc., and has obvious advantages in high-performance magneto-optical isolator.

The invention relates to the technical field of laser, in particular to a high-signal-to-noise-ratio modulation transfer spectrum frequency stabilization light path system. The system comprises a laser, an optical isolator, a first half-wave plate, a first polarization splitting prism, an optical fiber coupler, a second half-wave plate, a second polarization splitting prism, a first reflecting mirror, an electro-optical modulator, a second reflecting mirror and a third polarization splitting prism, wherein the first half-wave plate is used for adjusting the power of frequency stabilization light; the second half-wave plate is used for adjusting the power ratio of pump light to probe light; a first quarter-wave plate, a second quarter-wave plate, an atomic gas chamber and a photoelectric detector; after the output of the laser is isolated by the optical isolator, the first half-wave plate and the first polarization splitting prism are matched to adjust the frequency stabilization total beam power to about 5mW; the pump light is modulated by the electro-optical modulator, the probe light and the pump light reversely interact in the atomic gas chamber in an anti-phase circular polarization state, and the signal-to-noise ratio of a modulation transfer signal and the stability of a frequency stabilization system are remarkably improved.

The embodiment of the utility model discloses an optical device and near-to-eye display equipment, the optical device comprises a projection light source, an optical isolator and a diffraction optical waveguide, the projection light source is used for emitting image light; the diffractive optical waveguide comprises a coupling grating; image light emitted by the projection light source passes through the optical isolator and then enters the coupling-in grating, and after being diffracted by the coupling-in grating, the image light returns to the optical isolator and cannot return to the projection light source. According to the technical scheme disclosed by the invention, the light rays diffracted and returned by the coupled grating can be prevented from entering the projection light source to form a ghosting image.

The invention discloses a green laser assembly, an optical module and application of the green laser assembly in photovoltaic assembly processing, a shell is provided with a first fixed reflector coated with a reflecting film for reflecting 1064nm, a first acousto-optic Q switch and a second acousto-optic Q switch are orthogonally arranged, an Nd: YAG laser uses an Nd: YAG crystal rod with the diameter of 6mm and the length of 166mm, and a second fixed reflector coated with a reflecting film for reflecting 1064nm is arranged on the Nd: YAG crystal rod. The first dichroscope transmits 1064nm and reflects 532nm to improve the conversion efficiency of frequency multiplication, the LBO crystal 16 is placed close to the second dichroscope to improve the power density and the conversion efficiency, and the second dichroscope reflects 1064nm and transmits 532nm. And the light with the wavelength of 532nm transmitted by the second dichroscope is coupled into an input end optical fiber of the optical fiber beam splitter after passing through the optical isolator and the first lens. The short-wavelength green laser is adopted, the photovoltaic welding strip is mainly composed of the copper base material and the tin alloy, the green laser absorptivity is far larger than the near-infrared wavelength (about 1 micron) absorptivity, and the laser absorptivity of the welding strip is remarkably improved.

The invention discloses a two-degree-of-freedom displacement simultaneous measurement system and method based on an orbital angular momentum beam interferometer. The system comprises a laser; the light field regulation and control module is used for converting the linearly polarized light into a light beam with orbital angular momentum; an optical isolator; a first beam splitter; a second beam splitter; the third beam splitter is used for combining the first reference light beam and the first measurement light beam to generate conjugate interference; a fourth beam splitter; a fifth beam splitter; the sixth beam splitter is used for combining the second reference light beam and the second measurement light beam to generate conjugate interference; a seventh beam splitter; a first reflector; a second reflector; a third reflector; a first Weive prism; a second Weive prism; a reflection grating; and the image acquisition and processing module is used for acquiring a petal-shaped interference pattern formed by conjugate interference. The system is compact in structure and high in demodulation sensitivity, and can realize non-contact and high-resolution synchronous two-degree-of-freedom measurement.

The invention relates to the technical field of spontaneous emission light sources, in particular to an integrated amplified spontaneous emission light source based on an erbium-doped waveguide, which comprises a pump laser, a wavelength division multiplexer, the erbium-doped waveguide, a waveguide reflecting region, a waveguide optical isolator and a waveguide filter, and is characterized in that the wavelength division multiplexer is provided with an input end, a first output end and a second output end; the pump laser is connected with the input end of the wavelength division multiplexer, the second output end of the wavelength division multiplexer is connected with the waveguide reflection area, the first output end of the wavelength division multiplexer is connected to the input end of the erbium-doped waveguide, the output end of the erbium-doped waveguide is connected to the input end of the waveguide optical isolator, and the output end of the waveguide optical isolator is connected with the waveguide filter; the size of the light source is greatly reduced through the integrated waveguide design, and the performance of the light source is guaranteed under the condition that the size of the light source is greatly reduced.

The invention relates to the technical field of optical fiber sensing and optical communication, and discloses a tunable semiconductor laser wavelength tuning system based on photoelectric feedback, which comprises a user control module, a modulation grating Y laser, a user application optical path, an optical splitter, an optical isolator, a photoelectric conversion circuit, a negative feedback amplification circuit and an adjustable current source circuit, and output light of the modulation grating Y laser passes through the optical splitter, one part of the output light enters the optical isolator and then enters the user application light path, and the other part of the output light enters the photoelectric conversion circuit and is input into the negative feedback amplification circuit, so that the adjustable current source circuit is controlled, SOA current is controlled to be output to the modulation grating Y laser, and the output light power is changed. In the calibration and normal working process of the modulation grating Y laser, the optical power output by the laser is collected in real time through the optical splitter, negative feedback is formed at the SOA current, and only the left current, the right current and the phase current need to be input, and the proper SOA current is automatically matched for power compensation.

The invention discloses a detection auxiliary device of a magneto-optical isolator, and belongs to the technical field of detection auxiliary devices. The device comprises a detection table; the base is fixedly connected to the bottom of the detection table; the auxiliary transmission structure is mounted at the top of the outer surface of the detection table; the adjustable limiting structure is mounted on one side of the auxiliary transmission structure; and the light guide shielding structure is mounted on one side of the detection table. According to the device, under the action of the auxiliary transmission structure, the position of the adjustable limiting structure can be changed, then auxiliary limiting can be carried out on the magneto-optical isolator under the action of the adjustable limiting structure, due to the three clamping grooves in different shapes, the adjustable limiting structure can clamp the magneto-optical isolators in different shapes, and therefore the clamping effect of the magneto-optical isolators is improved. Due to the fact that the three clamping grooves and related structures are arranged in a circumferential mode, the clamping groove actually playing a clamping role is located under the clamping groove, the other two clamping grooves are located above the clamping groove, and the three clamping grooves and the related structures cannot affect each other.

The application discloses a disk medium high-energy ultra-short pulse laser regenerative amplifier based on CPA technology, comprising: a femtosecond laser seed light source for providing femtosecond seed light; a chirped Bragg fiber grating for expanding the femtosecond seed light into nanosecond laser pulses; an optical coupling input and output device for coupling input of the nanosecond laser pulses and coupling output of the nanosecond laser pulses after amplification processing; a regenerative amplification laser cavity for regenerative amplification processing of the coupled-in nanosecond laser pulses; the optical coupling input and output device comprises a fiber coupling collimation module, an optical isolator, a first 1 / 2 wave plate and a thin film polarizer; the regenerative amplification laser cavity comprises a Pockels cell, a second 1 / 2 wave plate, a first reflection module, a second reflection module, a first telescope module, a second telescope module, a first disk gain medium, a second disk gain medium and a third reflection module; the regenerative amplifier can realize high-repetition-frequency and high-pulse-energy laser pulse output.

The invention provides an optical feedback resonance enhanced forward Brillouin demodulation structure, which comprises a tunable laser, a first polarization controller, an erbium-doped optical fiber amplifier, an optical coupler, an optical isolator, a forward Brillouin gain optical fiber, a band-pass filter and a photoelectric detector, a second polarization controller; and a spectrum analyzer. The first polarization controller is connected with a port a of the optical coupler, a port b of the optical coupler is connected with an input end of the erbium-doped optical fiber amplifier, an output end of the erbium-doped optical fiber amplifier is connected with the optical isolator, the optical isolator is connected with the band-pass filter, the band-pass filter is connected with the forward Brillouin gain optical fiber, and the optical fiber is fed back to a port c of the coupler through the second polarization controller. The output power of the erbium-doped optical fiber amplifier is controlled, and the polarization states of the pump light and the feedback laser are controlled by the first polarization controller and the second polarization controller, so that the forward Brillouin effect is amplified.

The invention provides a self-calibration high-strength optical fiber hydrophone based on an end face reflection principle, and relates to the technical field of hydrophones. Comprising the steps that a laser light source emits a first laser beam, and an optical fiber isolator suppresses reflection and outputs a second laser beam. And the optical fiber variable optical attenuator adjusts the incident power and outputs a third laser beam. The 1 * 2 optical fiber coupler splits the laser beam into a fourth laser beam and a fifth laser beam, and the first photoelectric detector monitors power. The optical fiber circulator transmits the fifth laser beam to the optical fiber sensing module, generates reflected light and transmits the reflected light to the second photoelectric detector, and the second photoelectric detector converts the reflected light into a voltage signal. The data acquisition card acquires the signals, the signal demodulation processing unit calculates sound pressure sensitivity according to a mapping relation formula of the voltage signals and sound pressure, and the standard voltage module provides standard voltage for the data acquisition card. The problem that in the prior art, a high-strength hydrophone cannot be repeatedly used and cannot be self-calibrated after being damaged is solved.

The invention relates to a sulfur-antimony-lanthanum-barium compound, a sulfur-antimony-lanthanum-barium mid-far infrared birefringent optical crystal and a preparation method and application thereof, relates to a mid-far infrared birefringent crystal and a preparation method and application thereof, and aims to solve the problem of low birefringence of the existing mid-far infrared crystal, the sulfur-antimony-lanthanum-barium compound has the chemical formula of Ba2La2Sb4S10 (S2) and the molecular weight of 1424.22, is crystallized in a monoclinic system, and has the molecular weight of 294nm. The space group is P21 / c, and the cell parameters are as follows: a = 8.6373 (5), b = 14.7336 (9), c = 15.9161 (9), alpha = gamma = 90 degrees, and beta = 92.661 (2) degrees. Preparing a compound or a polycrystal material by using a high-temperature solution or a solid-phase method; a polycrystalline material is used for growing a single crystal, the birefringence of the single crystal is 0.53 at the position of 1064 nm, the single crystal has large birefringence within the range of 1-14 microns, and the single crystal is used in an optical isolator, a circulator, a beam shifter, an optical polarizer or an optical modulator.

This application relates to a polarization-maintaining isolator and optical device. The polarization-maintaining isolator includes a first collimator, a first polarizer, a Faraday rotator, a second polarizer, and a second collimator arranged sequentially along the optical path. The transmission axis of the first polarizer is along a first target polarization direction; the Faraday rotation angle of the Faraday rotator is equal to the target angle; the transmission axis of the second polarizer is along a second target polarization direction; the first target polarization direction, after being rotated by the target angle, is aligned with the second target polarization direction; and the second target polarization direction, after being rotated by the target angle, is perpendicular to the first target polarization direction. This application simplifies the device structure and reduces the space occupied by the device, achieving a compact design for the optical isolator.

This invention provides a cross-network interaction method and system based on the irreversible and wave properties of light, relating to the field of network security technology. The method includes obtaining modulation sensitivity factors through multi-scale decomposition, using an asymmetric modulation operator for dynamic compensation modulation to generate an optical signal carrying unique wave information, establishing a unidirectional transmission link using an optical isolator, and generating check values ​​through wave feature sequences and feature mapping matrices respectively, comparing matching degrees to determine data integrity. This invention achieves secure and efficient data interaction between heterogeneous networks, effectively preventing data leakage and tampering, and improving the security and reliability of cross-network data transmission.

The invention provides a silicon optical device and a coupling method thereof. The silicon optical device comprises a circuit board; a heat dissipation substrate, a silicon optical chip, an optical isolator and a lens unit are arranged above the circuit board, a plurality of lasers are arranged above the heat dissipation substrate, the lens unit comprises a collimating lens array, a half-reflecting mirror and a converging lens array, the collimating lens array and the converging lens array are vertically arranged, and the half-reflecting mirror is arranged above the collimating lens array. The first end of the collimating lens array is adjacent to the first end of the converging lens array, the second end of the collimating lens array is adjacent to the first end of the half-reflecting mirror, and the second end of the converging lens array is adjacent to the second end of the half-reflecting mirror; the collimating lens array directly faces the plurality of lasers, and the silicon optical chip directly faces the converging lens array. And the optical isolator is arranged between the converging lens array and the silicon optical chip. The space of the circuit board can be fully utilized, so that the packaging density is improved.

This invention provides a wind erosion monitoring system and method based on distributed optical fiber, belonging to the field of optical-based wind and sand monitoring technology. It includes: constructing a wind erosion monitoring system comprising a linearly tunable laser, an optical isolator, a first coupler, an upper branch, a lower branch, a sand particle capture sensor, a photoelectric detection and acquisition module, and a host computer; utilizing the Rayleigh scattering signal of the linearly swept laser in the sensing optical fiber and the interference with a reference light, the vibration information distributed along the optical fiber is obtained by demodulating the beat frequency signal; combining the constructed sand particle impact and optical fiber coupling model, the dynamic strain generated by sand particle impact is converted into phase changes, realizing the acquisition of sand particle impact location, sand particle size, and sand particle quantity. This invention enables continuous distributed monitoring of wind and sand flows with high spatial resolution, and has advantages such as resistance to electromagnetic interference, strong environmental adaptability, and multi-parameter sensing, and can operate stably for a long time in harsh desert environments.

This invention relates to a high-power narrow-linewidth laser with weak feedback in an external cavity, comprising: a sub-source output section for outputting a sub-source; a laser output section for outputting narrow-linewidth laser light; an isolator disposed between the sub-source output section and the laser output section; a multilayer reflective film assembly deposited on the input end of the isolator or on the output end of the sub-source output section for filtering the sub-source to form transmitted light and feedback light; the rear end of the isolator outputs the transmitted light to the laser output section as narrow-linewidth laser output; the sub-source output section also receives the feedback light to achieve self-injection locking, possessing the advantages of high-power narrow-linewidth laser output, simple structure, low cost, simple process, relatively small packaging size, and ease of laser packaging.

This invention discloses an integrated detection device for the isolation degree of an optical isolator, belonging to the field of optical component manufacturing technology. The device includes a top connecting plate, a supporting vertical plate fixedly connected to the back of a bottom supporting plate, a top connecting plate fixedly connected to the front of the upper end of the supporting vertical plate, and a connecting pipe arranged opposite to each other detachably between the top connecting plate and the bottom supporting plate. An adjustment component is installed on the two connecting pipes below the depolarizing beam splitter prism, and an isolator is installed on the adjustment component. The isolator and the reflector are coaxial. Through the principle of dual-source independent optical path synchronous acquisition, the two light sources are transmitted through the depolarizing beam splitter prism to form a test optical path and a reference compensation optical path, respectively, and the reverse leakage power of the isolator is acquired synchronously. This avoids the light source drift and optical path loss drift errors caused by time difference in traditional single-path step measurement.

The application discloses a kind of based on functional echo wall mode optical microbottle cavity Full light tuning controllable optical comb generation method. Including 1550nm narrow line width continuous wave laser, single-mode optical fiber, erbium-doped fiber amplifier, polarization controller, optical isolator, functional microbottle cavity-fiber taper coupling system, optical attenuator, optical spectrum analyzer and 1550nm power adjustable laser. The unique axial characteristics of echo wall mode microbottle cavity are used, the free spectral range of microcavity is reduced, the axial mode microcavity optical frequency comb with small free spectral range is generated, and based on full light tuning method, functional microbottle cavity is prepared, and the axial mode microcavity optical frequency comb generated is tuned by photo-thermal material titanium dioxide, and significant spectral range tuning is realized. The application solves the limitation that WGM microcavity optical frequency comb cannot be effectively tuned due to large free spectral range, and helps the practical application in the field of microcavity optical frequency comb optical communication, optical frequency synthesis and the like.

The present application relates to the technical field of measurement, in particular to a kind of spectrometer automatic calibration device and method, comprising: light source, optical isolator, fiber coupler, standard reference light source, adjustable fiber attenuator, first fiber collimator, holographic frequency selection module, electric reflector, volume holographic grating, second fiber collimator, beam splitter, optical interface unit, to be measured spectrometer, photoelectric detector, electric reflector driver, angle-second level angle encoder, control module, communication module, computer and image display unit.The present application utilizes volume holographic grating to select the corresponding relationship between the pixel of spectrometer and wavelength, can continuously select monochromatic light, and the theoretical resolution is consistent with the spectral resolution of light source;Using automatic calibration method, the automatic calibration of spectrometer is realized, pixel-wavelength calibration data can be automatically generated and stored in preset format, which is convenient for automatic calibration and data processing of spectral measurement software, and realizes wavelength-pixel position registration at pixel level.

To provide polarizing glass having a glass substrate that has excellent chemical durability, is suppressed from an increase of raw material cost, and is reduced in photochromic characteristics.SOLUTION: A polarizing glass containing shape-anisotropic metal particles that are oriented and dispersed at least in a surface layer of a glass substrate, wherein the glass substrate, expressed in mass percent, comprises SiO2: 50.0 to 65.0%, B2O3: 10.0 to 22.0%, Al2O3: 5.0 to 10.0%, Li2O: 3.0% or less, Na2O: 9.0% or less, K2O: 16.0% or less, a total content of Li2O, Na2O, and K2O [Li2O+Na2O+K2O]: 6.0 to 18.0%, ZrO2: 2.0 to 8.0%, TiO2: 1.10 to 1.80%, Ag: 0.10 to 0.35%, and Cl and Br in a total chemical equivalent amount equal to or greater than that of Ag, and wherein the shape-anisotropic metal particles are metal Ag particles.SELECTED DRAWING: None

An optical signal amplifier using a praseodymium doped fiber is described. The optical signal amplifier includes a signal laser, a first optical isolator, a second optical isolator a pump laser, a wave division multiplexer, a silica based glass optical fiber, a second optical isolator, an optical power meter, and an optical spectrum analyzer (OSA). The signal laser generates a signal laser beam. The pump laser generates a pumped laser beam. The wave division multiplexer combines the signal laser beam and the pumped laser beam and generates a combined laser beam. The silica based glass optical fiber has a preferred concentration of praseodymium ions of about 50×1024 ions / m3 and a length of about 5.7 m. The silica based glass optical fiber receives the combined laser beam, amplifies photons in the combined laser beam, and generates an amplified laser beam.

The utility model relates to a magneto-optical isolator and laser equipment. The magneto-optical isolator comprises a polarization light splitting element which can penetrate through first polarization light and block second polarization light, and the polarization light splitting element is provided with a first area and a second area; the optical rotation device is opposite to the first area; the magnetic optical rotation element is arranged on one side, opposite to the polarization light splitting element, of the optical rotation device and is provided with a third area and a fourth area; the conduction assembly enables light rays entering the magnetic rotation element from one of the third area and the fourth area to go back and forth in the magnetic rotation element and then to be emitted out from the other one of the third area and the fourth area; light emitted from the first area is converted into one of first polarization state light and second polarization state light after passing through the optical rotation device and the magnetic optical rotation element, and light emitted from the second area is converted into the other one of the first polarization state light and the second polarization state light after passing through the magnetic optical rotation element and the optical rotation device. According to the magneto-optical isolator, the miniaturization design can be realized.

The utility model relates to the technical field of optical equipment, in particular to an output type optical isolator, which comprises an optical rotation sheet with a groove mechanism and a small-hole diaphragm. When returning light appears, the plano-convex lens converges light spots of the returning light for the first time, the small-hole diaphragm partially blocks the converged light spots, and the energy of the returning light is reduced; the biconcave lens is used for carrying out secondary convergence on the blocked light spots; the second polarization splitting prism divides the secondarily converged light spots into reverse P light and reverse S light; under the combined action of the magnetic rotation crystal and an external magnetic field, the reverse P light and the reverse S light rotate anticlockwise; the optical rotation sheet performs first clockwise rotation on the reverse P light after counterclockwise rotation, and the groove mechanism of the optical rotation sheet completely blocks the reverse S light after counterclockwise rotation; finally, the rotated reverse P light and the blocked reverse S light cannot pass through the first polarization splitting prism to be combined, so that the reverse P light and the blocked reverse S light are isolated, and the damage of the returned light to a front-end laser element is avoided.

This specification relates to an optical particle counter, a method for using an optical particle counter, and a method for reducing particle counting errors during use of an optical particle counter. The method includes placing an optical isolator between a laser and a flow cell to allow laser light to pass through the flow cell and to reduce the intensity of light returned to the laser as optical feedback that could cause mode hopping.

The application discloses an SBS phase conjugation mirror capable of displaying a sound wave field in real time, and belongs to the technical field of nonlinear optics.The application comprises the following steps: pump light passes through a half-wave plate and a polarization beam splitter, passes through an optical isolator, changes a polarization state through a quarter-wave plate, is focused through a focusing lens, and then enters an SBS medium pool, stimulated Brillouin scattering occurs, a periodic density modulation is formed in the medium, and an equivalent acousto-optic grating structure is generated.Through introducing an independent probe light beam, the probe light enters the SBS medium pool at an incident angle satisfying the Bragg diffraction condition, and the probe light will be diffracted on the acousto-optic grating formed by the sound wave field.The intensity of the diffracted light changes with the intensity of the sound wave field, so that the real-time measurement of the sound wave field waveform and the life parameter in the SBS process can be realized by detecting the change of the diffracted light intensity with time.