31 results about "He ne laser" patented technology

The invention discloses a system and a method for detecting furfural in transformer oil based on a photo-thermal lens spectrum. A quantum cascade laser is used as pumping laser, and a helium-neon laser is used as detection laser; a visible light-infrared light dichroscope, a chopper, a reflector, an attenuator, a plano-convex lens, a fixed optical path liquid pool, an iris diaphragm, a photoelectric detector, a lock-in amplifier, an upper computer and the like are arranged, so that in-situ rapid, accurate and high-sensitivity quantitative detection of trace furfural in the transformer oil is realized; through the pumping laser covering the infrared characteristic absorption spectral line in furfural, trace furfural molecules in the transformer oil absorb the pumping laser with the average power exceeding 100 mW to excite a strong thermal lens effect, and the detection performance is remarkably improved; in-situ and rapid detection of furfural in the transformer oil is realized by utilizing a thermal lens effect generated by absorption of furfural in the transformer oil on mid-infrared light.

The invention discloses a crystal angle measuring and adjusting device and method for an off-axis pump folded laser. The device comprises a control terminal, a visible light camera, a precision displacement platform, an electric control displacement platform, a micron pumping source, a collimating focusing lens group, an incident plane-concave end mirror, a 2-micron laser crystal, a high-reflectivity plane-concave end mirror, an output coupling mirror OC, a diaphragm B, a 2-micron total reflective mirror, a helium-neon laser, a red light total reflective mirror and a diaphragm A; the method comprises the steps that the helium-neon laser outputs a red laser beam as a measuring beam, the red light total reflection mirror reflects and outputs the measuring beam, the measuring beam enters the right end face of the 2-micron laser crystal after passing through the high-reflection plano-concave end mirror, then the measuring beam is reflected to the high-reflection plano-concave end mirror through the right end face of the 2-micron laser crystal and then reflected to the diaphragm A through the high-reflection plano-concave end mirror, and the measuring beam is measured through the high-reflection plano-concave end mirror. Collecting an image through a visible light camera, and determining a light spot position through a control terminal; and the 2-micron laser crystal is adjusted by using the light spot position so as to ensure the stable transmission of the laser. The device and the method can realize automatic adjustment of the position and the angle of the crystal.

The invention discloses a quantitative laser speckle blood flow imaging method based on a neuromorphic visual sensor, and relates to the technical field of biomedical engineering. The method solves the problem that static scattered light caused by physiological behaviors and electronic noise of imaging equipment have adverse effects on blood flow imaging quality in a traditional laser speckle contrast imaging method, and comprises the following steps: step 1, using a helium-neon laser as a light source, and irradiating a scattering medium with an expanded laser beam to form a speckle pattern; 2, a microfluidic injector is adopted, two parameters of the inner diameter and the flow of the injector are set, and the flow speed range is controlled; 3, asynchronously sensing the change of the light intensity of the speckle pattern by using an event camera, and shooting the speckle pattern by using a frame camera; and 4, acquiring event stream data by the event camera, and processing the data by using an algorithm. Real-time and high-resolution blood flow imaging and flow velocity calculation are achieved, and the inherent limitation of a traditional method is overcome.

The utility model discloses an angle magnification optical diffraction experiment device. Comprising a one-dimensional optical slide rail, and a helium-neon laser, a one-dimensional arrangement lens group and a receiving measurement assembly which are sequentially arranged at intervals along an optical axis from an object side to an image side, and samples used for diffraction experiments are arranged among lenses in the one-dimensional arrangement lens group along the optical axis direction. The one-dimensional arrangement lens group, the receiving and measuring assembly and the sample are slidably mounted on the one-dimensional optical slide rail; and the helium-neon laser and the one-dimensional optical slide rail are both arranged on the top surface of the optical platform. According to the utility model, through the beam expanding light path and the angle amplification light path which are formed by the lens group, the diameter of the laser beam and the diffraction angle are respectively enlarged, so that diffraction spots of a macroscopic object are clearly visible on a naked eye resolution scale, the device can be used for displaying diffraction and interference phenomena of various large-size structures, and the whole set of device is simple, compact and convenient to use. The device is clear in structure, has high flexibility, and can be widely applied to physical optical experiment teaching.

The application discloses a photoacoustic spectrum signal detection system and a detection method. The system comprises a signal acquisition device and a detection signal processing terminal. The signal acquisition device comprises an ultraviolet pulse laser, a first plano-convex lens, a second plano-convex lens, a focusing objective lens, a refractive prism, a helium-neon laser, an electric displacement platform, a polarization modulation assembly, a light splitting assembly and a differential detector. The photoacoustic spectrum signal detection system uses the specific absorption of cell nuclei to ultraviolet light, obtains a differential detection signal through the differential detector and generates an analysis spectrum. The light sensing assembly collects a light sensing signal of the sample and generates a microscopic image. The detection system can realize photoacoustic spectrum analysis of a cell nucleus level micro-sized absorber, thereby obtaining a high-resolution analysis spectrum and a microscopic image reflecting the physical properties inside the cell nuclei. The label-free and non-staining photoacoustic spectrum signal detection does not need staining and can save detection time, and the accuracy of cell detection on biological samples is improved.

The application discloses a vortex light interference device and method for measuring three-dimensional vibration and sound field rotation characteristics, wherein a helium-neon laser emits laser light, the laser light passes through a half-wave plate and a first polarization beam splitter prism, and is divided into object light and reference light; the object light passes through a first spiral phase plate and becomes vortex object light, the vortex object light passes through a second polarization beam splitter prism, a quarter-wave plate, and a beam expander lens, and is irradiated on a test sample surface, reflected light of the sample surface passes through the beam expander lens, the quarter-wave plate, the second polarization beam splitter prism, a beam splitter prism and a focusing lens, and is irradiated on a photodetector; the reference light passes through an acousto-optic modulator to generate frequency modulation, passes through a mirror and a second spiral phase plate to become frequency-modulated vortex light, and the vortex light passes through a beam splitter prism and a focusing lens and is irradiated on the photodetector; a computer calculates and demodulates frequency-modulated signals of the photodetector and modulation signals of the acousto-optic modulator, and finally obtains three-dimensional vibration information and sound field rotation characteristics of the sample.

The invention discloses a rapid assembling and adjusting device for a space beam combining reflector group. The rapid assembling and adjusting device comprises a helium-neon laser (1), a total reflection mirror (2) with a center hole, a rotary table simulation mechanism (3), a reflector diaphragm (4), an autocollimator (5), an internal diaphragm (6), a beam combining box (7) and a primary mirror (8). A helium-neon laser (1), a total reflection mirror (2) with a center hole and an internal diaphragm (6) are coaxially installed on the rotary table simulation mechanism (3) from top to bottom. The rotary table simulation mechanism (3) is arranged at the center of the top surface of the beam combining box (7); the primary mirror (8) is arranged in the beam combining box (7) and is positioned right below the internal diaphragm (6); the mirror surface of the primary mirror (8) is provided with a reflector diaphragm (4); and the autocollimator (5) is erected outside the beam combining box (7), and the emergent light of the autocollimator (5) is consistent with the reflected light path of the primary mirror (8). According to the invention, the autocollimator is adopted to replace laser of different wavebands, is not limited by the adjustment of the target wavebands, is suitable for the adjustment of the combined space beam combining system, and is wide in application range and high in practicability.

The present invention relates to a system and a modulation method for controlling the transmission mode of a KTN cladding waveguide by using temperature, and the technical characteristics thereof are: comprising a helium-neon laser light source A, a Glan-Taylor prism B, a focusing objective lens C, a cladding waveguide mode modulator D, an imaging objective lens E, a beam quality analyzer F and a temperature controller G; the helium-neon laser light source is connected to the Glan-Taylor prism, the other end of the Glan-Taylor prism is connected to the cladding waveguide mode modulator through the focusing objective lens, and the other end of the cladding waveguide mode modulator is connected to the beam quality analyzer through the imaging objective lens. The present invention realizes the control of the light field mode distribution at the output end of the KTN cladding waveguide.

The application discloses a laser optical axis debugging device and a debugging method, which comprise a fixing base, a laser generating mechanism, a target plate and a conversion base, the laser generating mechanism is arranged on the fixing base, one end of the laser generating mechanism is formed with a laser emission port, the target plate is arranged in a spaced mode with the laser generating mechanism, a through hole is formed in the middle of the target plate, the center of the through hole is coaxially arranged with the center of the laser emission port, the conversion base is sleeved on one side of the laser generating mechanism close to the laser emission port, and a laser to be debugged is sleeved outside the conversion base. The helium-neon laser and the reflecting mirror of the existing coarse adjustment scheme can be replaced, the formed collimating light path can solve the technical problems of low precision, large debugging difficulty, low stability and reliability of the optical axis of the prior art which are restricted by the site and equipment factors.

The application discloses a kind of based on valley power lockout semi-out cavity linear polarization interference light source and its design method.The device includes laser power supply, laser, heating wire, heat preservation glue, beam splitter BS, PD photocell and laser frequency stabilization system;Design method is crucial in that: the laser is three longitudinal mode semi-out cavity linear polarization helium-neon laser, laser built-in Brewster window, and the key parameters of the laser are calculated by longitudinal mode light intensity coupling model, two side modes can be completely suppressed, form the high proportion valley bottom in light intensity harmonic curve, to facilitate frequency stabilization algorithm identification to realize central longitudinal mode frequency locking.The method of the application can make the output power of the laser reach 2.4mW or more, overcome the shortcomings of traditional double longitudinal mode frequency stabilization interference light source power limitation, improve single mode power conversion efficiency, provide a new type of frequency stabilization technology and new type of interference light source for the rapid development of ultra-precision machining and measurement technology and various fields such as single mode conversion complete, high output power, good wavelength stability.

The utility model discloses a rapid assembling and adjusting device for a space beam combining reflector group. The rapid assembling and adjusting device comprises a helium-neon laser (1), a total reflection mirror (2) with a center hole, a rotary table simulation mechanism (3), a reflector diaphragm (4), an autocollimator (5), an internal diaphragm (6), a beam combining box (7) and a primary mirror (8). A helium-neon laser (1), a total reflection mirror (2) with a center hole and an internal diaphragm (6) are coaxially installed on the rotary table simulation mechanism (3) from top to bottom. The rotary table simulation mechanism (3) is arranged at the center of the top surface of the beam combining box (7); the primary mirror (8) is arranged in the beam combining box (7) and is positioned right below the internal diaphragm (6); the mirror surface of the primary mirror (8) is provided with a reflector diaphragm (4); and the autocollimator (5) is erected outside the beam combining box (7), and the emergent light of the autocollimator (5) is consistent with the reflected light path of the primary mirror (8). According to the utility model, the autocollimator is adopted to replace laser of different wavebands, is not limited by the adjustment of the target wavebands, is suitable for the adjustment of the combined space beam combining system, and is wide in application range and strong in practicability.

This invention provides an intelligent control system and method for optimizing the intracavity mode of a high-reflectivity cavity mirror helium-neon laser. The system includes: a mode detection module for real-time detection of the output beam of the high-reflectivity cavity mirror helium-neon laser using a beam analyzer and photoelectric sensors to acquire monitoring data; an intelligent control module for analyzing the monitoring data based on machine learning algorithms and automatically adjusting the angle and position of the high-reflectivity cavity mirror according to optimization requirements; and a compensation module for compensating for laser performance based on environmental and monitoring data. This invention's intelligent control system and method for optimizing the intracavity mode of a high-reflectivity cavity mirror helium-neon laser monitors and optimizes the intracavity mode of the helium-neon laser in real time, greatly improving the output beam quality and stability of the laser. The system can adapt to environmental changes, reducing manual intervention and significantly improving the system's control accuracy and efficiency.

The present invention discloses a spectrum and temperature measurement device and method for high-voltage spark discharge plasma; the device includes a scanning camera, a high-resolution spectrometer, an optical lens, a DG535 digital delay generator, a high-voltage pulse power supply, and a needle-tip discharge device; the method includes using a 632.8nm helium-neon laser to calibrate the wavelength of the device; using the constructed device to detect the spectrum of the spark discharge plasma; using a radiation calibration light source halogen tungsten lamp to calibrate the radiation intensity of the device; and calculating the temperature of the spark discharge plasma. The present invention takes a scanning camera and a spectrometer as the core, combines Planck's blackbody radiation theory, and collects spark discharge spectra to achieve temperature diagnosis of discharge plasma. Compared with traditional optical pyrometers, both the range of the detection spectrum and the spectral resolution and time resolution of the temperature measurement system have been significantly improved.

The application discloses a kind of based on locking confocal F-P cavity laser sweep quantity accurate control and determination device and method.The device is by the wave division multiplexing of low-frequency electro-optic phase modulator to realize the locking of confocal F-P cavity length relative to helium-neon laser and the locking of tunable laser frequency relative to confocal F-P cavity at the beginning and end of scanning;Before laser scanning, confocal F-P cavity free spectral range FSR is measured by high-frequency electro-optic phase modulator with microwave frequency reference, and the number of scanning resonance peaks between two laser frequency lockings is counted to realize sweep quantity control and determination.The application realizes the control and measurement of laser frequency scanning quantity in frequency scanning interference method, improves the stability of confocal F-P cavity FSR as scanning frequency reference, and realizes high-precision measurement of FSR with microwave frequency reference, so as to improve the frequency scanning measurement accuracy, so as to improve the accuracy of sweep absolute ranging.

The utility model discloses a double-end-face interference thickness measuring device. The double-end-face interference thickness measuring device comprises an optical platform and a shell. Comprising an optical base (1) and a shell (2), a helium-neon laser (3), a reflector 1 (4), a reflector 2 (5), a beam expander (6), a convergent lens (7) and a reflector 3 (8) are arranged on the optical base (1), a spectroscope 1 (9) is distributed on one side in an S shape, the spectroscope 1 (9), the reflector 4 (10), the reflector 5 (11), a clamping body (12) and the reflector 6 (13) are distributed in an isosceles triangle shape, and a reticle (14) and a CCD camera (15) are distributed on the other side of the isosceles triangle. The clamping body comprises two spectroscopes (7) and a clamping part, and a motor is installed at the bottom of the clamping body. According to the invention, non-contact non-lapping-in double-end-face measurement of the material to be measured is carried out by using the partial wave surface interference concentric circular ring, so that the precision and the efficiency can be improved, the environmental requirement cost is saved, decimal overlap method operation is omitted, detection automation is facilitated, and direct traceability with national standard meter definition is realized.

The invention discloses a polarization type measuring device and method based on vortex light interference, and belongs to the technical field of laser interferometers. Laser emitted by a helium-neon laser passes through a first lens group to be split into horizontal line polarized light and vertical line polarized light; the horizontal line polarized light serves as a measurement light beam, and the displacement variation to be measured is regulated and controlled through phase control of the first phase control assembly; the vertical linearly polarized light reference light beam realizes phase locking; and the displacement variation is calculated according to the light spot rotation angle value obtained by the light spot analyzer. The designed phase-locking control system obtains interference light intensity in real time and then adjusts voltage output to piezoelectric ceramics to complete phase locking, and interference of the external environment on the whole light path system is overcome. In addition, the phase-locked control system designed by the invention can realize locking of any phase, and has a great assistance effect on a traditional intensity type interferometer.

The invention discloses a half external cavity linear polarization interference light source based on valley value power locking and a design method thereof. The device comprises a laser power supply, a laser, a heating wire, heat preservation glue, an optical splitter BS, a PD photocell and a laser frequency stabilization system. The design method is characterized in that the laser is a three-longitudinal-mode half-external-cavity line partial helium-neon laser, a Brewster window is arranged in the laser, key parameters of the laser are obtained through calculation of a longitudinal mode light intensity coupling model, two side modes can be completely restrained, a high-proportion valley bottom in a light intensity tuning curve is formed, and the high-proportion valley bottom in the light intensity tuning curve is formed. And central longitudinal mode frequency locking can be realized through frequency stabilization algorithm identification. According to the method, the output power of the laser can reach 2.4 mW or above, the defect that the power of a traditional double-longitudinal-mode frequency stabilization interference light source is limited is overcome, and the single-mode power conversion efficiency is improved; a novel frequency stabilization technology and a novel interference light source which are complete in single-mode conversion, high in output power and good in wavelength stability are provided for various fields such as rapidly-developed ultra-precision machining and measuring technologies.

The utility model discloses an anti-pollution structure of a helium-neon laser, which comprises a cathode end valveable metal body and an anode end valveable metal body, the upper end of the anode end valveable metal body is provided with a glass material layer, and one side of the upper end of the anode end valveable metal body is connected with a tungsten rod. The tungsten rod penetrates through the glass material layer and extends to the upper end of the anode end valvable metal body, and a laser shell glass tube is connected between the cathode end valvable metal body and the anode end valvable metal body. According to the utility model, the inner surface of the anode end metal is covered by the glass material so as to prevent the anode end valveable metal from discharging to the cathode, the tungsten rod is additionally arranged as the anode of the laser, and the laser anode end valveable metal is not used as the electrode of the laser and does not participate in high-voltage discharge of the laser, so that the laser anode end valveable metal is not ionized and gasified; pollution caused by ionization and gasification of the anode end kovar metal can be effectively prevented, and the service life of the laser is prolonged.

The application discloses a system and method for detecting furfural based on a Moire-enhanced differential photothermal lens spectrum, wherein a quantum cascade laser is used as a pumping light source, a helium-neon laser is used as a detection light source, and a dichroic mirror is used to realize coaxial incidence of the pumping light and the detection light; the pumping light is chopped and modulated and focused into a fixed optical path liquid pool to excite a thermal lens effect; the detection light is diffracted by a sample to generate a diffraction circle; the diffraction circle is subjected to spatial beat frequency amplification by a Moire circle grating; then, the diffraction circle enters a silicon bias photodetector through a variable diaphragm; a detection signal is differentially demodulated by a lock-in amplifier and processed by an upper computer. By using the spatial beat frequency amplification effect of the Moire circle grating, optical amplification is realized, and the sensitivity of the detection system is greatly improved; in combination with a differential detection structure, common-mode noise caused by light source power fluctuation, environmental vibration and temperature drift is effectively suppressed, and the signal-to-noise ratio and long-term stability of the detection system are greatly improved.

The invention provides an infinitesimal displacement measurement method and system based on a laser self-mixing interferometer, and relates to the technical field of displacement measurement, and the method comprises the steps: obtaining a to-be-measured object; the method comprises the following steps: modulating a self-mixing interferometer through a sinusoidal phase of a helium-neon laser, and extracting an interference signal containing displacement information of an object to be measured; extracting an in-phase component and an orthogonal component from the interference signal through a phase generation carrier technology to form an orthogonal signal pair; correcting a Lissajous figure generated by the orthogonal signal pair by using an ellipse fitting algorithm to obtain a corrected orthogonal signal pair; phase demodulation is carried out on the corrected orthogonal signal pair, and phase information of the object to be measured is extracted; and determining the displacement of the to-be-measured object based on the phase information. According to the method, the ellipse fitting algorithm is used for correcting the Lissajous figure generated by the orthogonal signal pair, non-ideal factors are effectively compensated in the process, the phase demodulation precision is guaranteed, and the displacement measurement accuracy is remarkably improved.

The invention provides an electronic water pump multi-mode cooperative control method and system based on LIN / PWM communication, electronic equipment and a storage medium, and relates to the technical field of vehicle thermal management systems.The method includes the steps that a vehicle turbocharging system pipeline pressure signal is collected, and frequency band energy analysis is conducted to obtain frequency spectrum energy information; a laser beam is emitted by the surface of an intercooler of a helium-neon laser, and vibration signals are inverted to obtain vibration mode information; the conditional generative adversarial network establishes a pressure and vibration incidence relation and generates a system coupling confidence parameter; multi-water pump working point distributed optimization is carried out to generate a cooperative control instruction; constructing a PWM signal sequence to form a control signal; and finally, a control signal is transmitted in a time division multiple access mode based on the LIN / PWM communication bus, and multi-mode cooperative control of the electronic water pump is achieved. Intelligent cooperative control of multiple electronic water pumps in a vehicle thermal management system can be realized.

The present invention discloses a quantitative laser speckle blood flow imaging method based on a neuromorphic visual sensor. This method relates to the field of biomedical engineering technology and addresses the problem in traditional laser speckle contrast imaging methods where static scattered light caused by physiological behavior and electronic noise from the imaging device adversely affect the quality of blood flow imaging. The method comprises the following steps: Step 1: Using a helium-neon laser as a light source, an expanded laser beam is irradiated onto a scattering medium to form a speckle pattern; Step 2: Using a microfluidic syringe, the syringe's inner diameter and flow rate are set to control the flow rate range; Step 3: Using an event camera to asynchronously sense changes in the speckle pattern's light intensity, and capturing the speckle pattern using a "frame" camera; Step 4: The event camera acquires event stream data, which is then processed using an algorithm. This method achieves real-time, high-resolution blood flow imaging and flow rate calculation, overcoming the inherent limitations of traditional methods.

The visible light waveband semiconductor laser microlens assembling and adjusting device belongs to the technical field of semiconductor laser optical assembling and adjusting, and is characterized in that a six-dimensional optical adjusting frame, a helium-neon laser system, an imaging monitoring system, a light spot image acquisition system, a beam quality detection system, a beam splitter, a focusing mirror I, a focusing mirror II and a laser heat sink are arranged on an optical platform, a lens clamp is arranged on the optical adjusting frame, and a semiconductor laser is arranged on the laser heat sink. The helium-neon laser is used to adjust the angle of the microlens, and the laser emitted by the semiconductor laser is used to irradiate on the beam quality analyzer and the CMOS to test the index and the collected image, so that the microlens is adjusted to the best position, and the assembling and adjusting precision is high.

The present invention discloses a furfural detection system and method in transformer oil based on photothermal lens spectroscopy. A quantum cascade laser is used as the pump laser, and a helium-neon laser is used as the probe laser. A visible-infrared dichroic mirror, a chopper, a reflector, an attenuation adjuster, a plano-convex lens, a fixed optical path liquid cell, a variable aperture, a photodetector, a lock-in amplifier, and a host computer are provided, etc., realizing in-situ, rapid, accurate, and highly sensitive quantitative detection of trace furfural in transformer oil. Through the pump laser covering the mid-infrared characteristic absorption spectral line of furfural, after trace furfural molecules in transformer oil absorb the pump laser with an average power exceeding 100 mW, a strong photothermal lens effect is excited, significantly improving the detection performance. By using the photothermal lens effect generated by the absorption of mid-infrared light by furfural in transformer oil, in-situ and rapid detection of furfural in transformer oil is realized.

The application discloses a device for generating annular structured light and a preparation method thereof, and the device comprises a helium-neon laser, a polarizer, a liquid crystal cell, an LED ultraviolet light source and a CCD which are sequentially arranged; the liquid crystal cell comprises two layers of substrates which are coated with orientation films, spacer particles and a liquid crystal layer, the spacer particles are arranged between the two layers of the orientation films of the substrates which are opposite to each other, and a filling space is formed for injecting the liquid crystal layer; the method for generating the annular structured light comprises three parts of preparation of a reconfigurable liquid crystal superstructure system, light path building and annular structured light acquisition. The application realizes the generation of the annular structured light by using the liquid crystal material, and the method for generating the amplitude type structured light by using the reconfigurable liquid crystal superstructure system has the advantages of simplicity, quickness, flexibility, reliability, low cost, reconfigurability and integration.

The invention discloses a greenhouse gas monitoring device under intermediate infrared wavelength. The detection unit comprises an absorption cell, the absorption cell comprises a light inlet for allowing incident light to pass through, a light outlet for allowing emergent light to pass through, a first reflecting mirror and a second reflecting mirror, and the vertical distance between the first reflecting mirror and the second reflecting mirror is adjustable; the calibration light path comprises a helium-neon laser, a first adjusting assembly and a beam splitter, and infrared light emitted by the helium-neon laser is adjusted by the first adjusting assembly and then enters the light inlet through a reflection point on the beam splitter; the detection light path comprises a mid-infrared laser and a second adjusting assembly. Detection light emitted by the mid-infrared laser is adjusted by the second adjusting assembly and then is transmitted to the light inlet through a reflection point on the beam splitter. According to the greenhouse gas monitoring device under the mid-infrared wavelength, the length of an optical path in the absorption cell is changed, the measurement precision of the absorption cell on gases in various concentration ranges is improved, and the accurate monitoring task for carbon emission of a park is effectively met.

The present invention discloses a collimation system for an optical fiber end cap and a collimation test method thereof. A helium-neon laser can generate helium-neon light. An optical fiber end cap and an aspherical mirror are respectively installed at the two ends of the barrel of the lens barrel, and an optical path is formed between the barrel cavity of the lens barrel and the output end of the helium-neon laser. A first CCD is disposed between the first mirror frame and the optical fiber end cap assembly, and the first CCD has an imaging film. The helium-neon light beam can form a spot image on the imaging film. A first aperture stop is disposed on one side of the optical fiber end cap assembly. The first aperture stop has an aperture stop hole, and the aperture stop hole of the first aperture stop is located on the optical path. A second aperture stop is disposed between the helium-neon laser and the first CCD. The first aperture stop has an aperture stop hole, and the aperture stop hole of the second aperture stop is located on the optical path. The beam quality of the laser output is ensured.

The present invention relates to the field of optical communication-related computing technologies, and specifically to an experimental method and apparatus for measuring the orbital angular momentum spectrum of a vortex beam based on coaxial interferometry. The method comprises a helium-neon laser, a beam expansion and collimation system, a spectroscopic modulation component, a spatial light modulator, a phase polarization adjustment component, and a charge-coupled device (CCD) camera. The spatial light modulator is disposed on the optical path of the Gaussian beam output by the helium-neon laser, and a CCD camera is disposed at the end of the optical path of the beam modulated by the spatial light modulator. The beam expansion and collimation system and the spectroscopic modulation component are coaxially disposed in sequence on the optical path between the helium-neon laser and the spatial light modulator, and the phase polarization adjustment component is coaxially disposed on the optical path between the spatial light modulator and the CCD camera. The present invention utilizes a small amount of experimental equipment to achieve stable coaxial interferometry of a vortex beam and accurate measurement of the orbital angular momentum spectrum, greatly reducing the difficulty of constructing the experimental interferometric optical path.

The present invention discloses a photoacoustic microscopy imaging system and an imaging method for large-depth imaging. The system includes a signal acquisition device and an imaging processing terminal. The signal acquisition device includes: a pulsed laser, a first beam splitter, a first polarizer, a first objective lens, a second beam splitter, a second polarizer, a second objective lens, a helium-neon laser, a polarizer, a dimming glass slide, a first filter, a second filter, a prism, a coupling medium, a first analyzer, a second analyzer, a differential detector, a band-pass filter, and an amplifier. The above photoacoustic microscopy imaging system outputs light beams based on a first optical path and a second optical path, realizes high-throughput and high-resolution focusing of the light beams on the sample through bidirectional excitation of the light beams, and uses a phase-type total internal reflection sensor as a photoacoustic wave detector. By analyzing the change in the refractive index of the coupling medium caused by the photoacoustic signal, broadband and high-sensitivity detection of photoacoustic waves is achieved, greatly improving the imaging quality of the sample.

The invention provides an intelligent regulation and control high-reflection cavity mirror helium-neon laser intracavity mode optimization system and method, and the system comprises a mode detection module which is used for detecting an output light beam of a high-reflection cavity mirror helium-neon laser in real time based on a light beam analyzer and a photoelectric sensor, and obtaining monitoring data; the intelligent control module is used for analyzing the monitoring data based on a machine learning algorithm and automatically adjusting the angle and the position of the high-reflection endoscope according to optimization requirements; and the compensation module is used for compensating the performance of the laser according to the environment data and the monitoring data. According to the intelligent regulation and control system and method for optimizing the intra-cavity mode of the He-Ne laser, the intra-cavity mode of the He-Ne laser is monitored and optimized in real time, the quality and stability of output light beams of the laser are greatly improved, the system can adapt to environmental changes, manual intervention is reduced, and the regulation and control precision and efficiency of the system are remarkably improved.