112 results about "Helium/neon laser" patented technology

The invention discloses a sinusoidal phase modulation type laser self-mixing interferometer and a measuring method thereof. The interferometer comprises a helium-neon laser, a variable neutral density filter, an electro-optical crystal modulator, a target to be measured, a photoelectric detector and a signal generator. The signal generator is used for generating sinusoidal signals with frequency of omega<m>, wherein one loop of signals is used for driving the electro-optical crystal modulator, one loop of signals is used as base-frequency signal output and the other loop of signals passes through a frequency doubler and a phase shifter and then outputs doubled-frequency signals with frequency of 2 omega<m>. The output of the photoelectric detector is amplified by an operational amplifier and then is respectively mixed with the base-frequency signals and the doubled-frequency signals to obtain two loops of signals. The signals are subject to low-pass filtering and then a computer unit controls an analog-to-digital conversion unit to acquire and demodulate a phase, so as to obtain and display the real-time displacement of the target to be measured. After the interferometer is calibrated, relative measurement accuracy of 10<-6>*L can be obtained, the measurement uncertainties within the measurement ranges of 100mum and 300mum are respectively 10nm and 0.15mum, and the measurable speed range is 0-60mm/s.

The equipment for monitoring micro circulation body flow time-space response characteristic on mesentery includes an optical path and an imaging system. In the optial path, the laser bean from helium neon laser is coupled to fiber bundle to form homogeneous diffused beam; and the imaging system consists of stereo microscope with CCD camera, image collecting card with image collecting and controlling software. The CCD signal is output to the image collecting card connected to PC, the collection parameters are set via the image collecting and controlling software and local blood flow information are obtained with the image signal and via the signal analysis software. The equipment provides one new way to the research of influence of medicine and other stimulation to the micro circulation blood flow on mesentery.

The invention relates to a cross-polarization laser feedback grating interferometer of a phase modulation type, and a measurement method thereof. The measurement principle is based on the grating diffraction, optical Doppler effect, Lamb semi-classical theory and time-domain orthogonal demodulation principle. The orthogonally polarized light outputted by a birefringent dual-frequency helium-neon laser is perpendicularly incident to a polarization beam splitting prism and is divided into two linearly polarized light beams in different polarization directions. The two polarized light beams respectively pass through two different electrooptical modulators and then are respectively reflected by a reflector at a +/-1-order Littrow incidence angle to a reflection-type diffraction grating. The diffracted light returns to the laser cavity along the respective incident light, and performs self-mixing interference with the light in the cavity. The backward output light of the laser passes through a polarizer and then only the single-mode light is retained and accepted by a photodetector. An output signal of the photodetector is outputted to a data processing module for data processing, and the two-dimensional displacement of a target to be measured is obtained. The grating interferometer has the advantages of simple structure, large measuring range and high measurement resolution.

The invention belongs to the technical field of surface charge accumulation characteristic testing of high-voltage direct current solid insulating material, and in particular relates to a measuring device of direct-current GIL basin-type insulator surface charge based on Pockels effect. The measuring device comprises a helium-neon laser, a polarized light separator, a high-speed camera, a 1/8 valve plate, bismuth silicate crystal, an insulating vacuum tube, a sliding block, a rotating shaft and an insulating guide rod. When measuring is conducted, a bismuth silicate probe is stuck to the surface of an basin-type insulator, a red laser is emitted from the helium-neon laser, the red laser is turned into elliptically polarized light through the polarized light separator and the 1/8 valve plate, the light entries into the bismuth silicate probe and is reflected at a division surface of bismuth silicate and the basin-type insulator, the light penetrates the 1/8 valve plate again and enters the high-speed camera after right-angle refraction is conducted on the light, optical intensity distribution is measured, and the size of the quantity of electric charge is acquired after being processed by a computer. The measuring device has the advantages that the structure is simple, the operation is convenient, and efficient measuring means is provided for studying of direct-current GIL basin-type insulator surface charge accumulation.

The inventors disclose a new high performance optical sensor, preferably of nanoscale dimensions, that functions at room temperature based on an extraordinary optoconductance (EOC) phenomenon, and preferably an inverse EOC (I-EOC) phenomenon, in a metal-semiconductor hybrid (MSH) structure having a semiconductor/metal interface. Such a design shows efficient photon sensing not exhibited by bare semiconductors. In experimentation with an exemplary embodiment, ultrahigh spatial resolution 4-point optoconductance measurements using Helium-Neon laser radiation reveal a strikingly large optoconductance property, an observed maximum measurement of 9460% EOC, for a 250 nm device. Such an exemplary EOC device also demonstrates specific detectivity higher than 5.06×10¹¹ cm√Hz/W for 632 nm illumination and a high dynamic response of 40 dB making such sensors technologically competitive for a wide range of practical applications.

The invention belongs to the field of geometric accuracy detection, and particularly discloses an error measurement system and method for a high-precision linear guide rail. The system comprises a fixed unit and a mobile unit, wherein the fixed unit is arranged on a fixed plane of a numerical control machine tool and comprises a helium-neon laser, a first beam splitter prism, a second beam splitter prism, a polarization beam splitter prism, a first 1/4 wave plate and a first four-quadrant detector; and the mobile unit is arranged on a mobile workbench of the numerical control machine tool andcomprises a pyramid prism. According to the invention, the pyramid prism which is insensitive to angles is adopted to measure the straightness error, so that the crosstalk and the measurement error caused by the angle change can be effectively avoided; meanwhile, the pyramid prism is arranged on the axis or the paraxial line, so that the influence of the Abbe error on the measurement result can beeffectively reduced, and the precision of the straightness measurement is improved; and the six-degree-of-freedom synchronous measurement can be realized by arranging other devices, and each error isdecoupled and separated, so that the accuracy of the measurement result is improved.

The invention relates to a device for detecting domain modulation of ferroelectric crystals in real time, and the device comprises a helium-neon laser, a filter, a collimating device, a first totally-reflection mirror, a second total-reflection mirror, a beam splitter prism, an imaging lens, a charge couple device (CCD) coupler and a computer. The device is contactless and free from damage and has high resolution ratio, not only can the dynamic variation of a domain structure be monitored in real time and quantitatively analyzed, but also the static response of the domain structure for an external electric field can be detected, and two-dimensional information and three-dimensional information of the reversal domain structure can be obtained.

A method for synthesizing dyes excitable by a helium-neon laser (excitable at 633 nm) from hololepidines, e.g., 7-halolepidine, which dyes are suitable for detection and enumeration of reticulocytes in human blood samples. In another aspect, the invention provides a method for immunotyping phenocytes. The method is based on the phenomenon that when dyes of certain structure intercalate into DNA or RNA, the intensity of the dye increases. Dyes suitable for this invention can be described as having (a) a first heterocyclic moiety, (b) a second heterocyclic moiety, and (c) a linking group that connects the first and second heterocyclic moieties. Both the first and second heterocyclic moieties must contain at least two rings, preferably fused together. The dye is characterized by conjugation, whereby the first moiety is ethylenically conjugated to the second moiety.

The invention discloses an optical measurement instrument and method for atmospheric coherent length. The optical measurement instrument for atmospheric coherent length comprises an He-Ne laser emission unit (1), a laser receiving and photovoltaic conversion unit (2), a data acquisition unit (3) and a data processing and analyzing unit (4), wherein the laser emission unit (1) comprises a He-Ne laser device 11 for emitting laser and a beam expanding device 12; and after a laser beam emitted by the He-Ne laser device 11 is expanded by the beam expanding device 12, the laser beam is transmitted by atmosphere turbulence and then vertically enters the laser receiving and photovoltaic conversion unit (2). The invention also discloses a measurement method for the optical measurement instrument. The optical measurement instrument has the advantages that influence the inner and outer scale of the atmosphere turbulence on the measurement method can be overcome very well, and the measurement result is more reasonable. The adopted position sensitive detector can directly give a position signal and a relative optical intensity signal, the memory is saved, and meanwhile, the requirement on the computer is lowered.

The invention relates to a method and device for generating a tunable self-split array vortex beam. The method includes the following steps that: a helium-neon laser is adopted to generate a laser beam, the laser beam is expanded by a beam expander, the correlation characteristic of the beam is modulated through a spatial light modulator, so that a beam having an array correlation characteristic can be obtained; the coherence of the beam is reduced through rotating frosted glass, so that a partially coherent beam having the array correlation characteristic can be obtained; the partially coherent beam having the array correlation characteristic passes through a Gaussian amplitude filter, so that an array-correlated Gaussian beam is obtained; the Gaussian beam passes through a vortex phase plate, so that an array-correlated vortex Gaussian beam can be obtained; and an array vortex beam is obtained on a far field by means of focusing. With the method and device of the invention adopted, the research of the beam with special coherence in aspects such as transmission, imaging and interaction with matters can be promoted, and beam types can be increased.

A nanometer measuring tape for helium-neon lasers with the wavelength of 1152 nm belongs to the technical field of laser-based displacement sensing, and is characterized in that the prior helium-neon laser with the wavelength being 632.8 nm is substituted for the helium-neon laser with the wavelength being 1152 nm to serve as the core of a nanometer measuring tape, so that the measuring range of the displacement is increased from 50 nm to higher than 100 nm under the condition that the resolution ratio (10 nm) remains unchanged. As the helium-neon laser with the wavelength being 1152 nm has higher gain, gain can be kept greater than loss when the inner cavity of the laser is exposed to air, therefore, the non-contact measurement of the separation between a gain pipe and a target lens is realized. By adopting a cat' s eye reflector as a target lens to be stuck with a target to be measured and designing the nanometer measuring tape into two structures with a full outer cavity and a semi-outer cavity respectively, the system has stronger stability, thereby becoming a steady and practical displacement sensor.

The invention relates to a phase modulation type laser feedback raster interferometer and a measuring method thereof. The structure of the phase modulation type laser feedback raster interferometer is that: the laser emitted from a helium-neon laser enters a transmission type diffraction grating through vertical incidence; each level of diffracted lights are symmetrically arranged at two sides of a incident light path; the displacement direction of the diffraction grating is perpendicular to the output light path of the laser; an electrooptical modulator is arranged on a light path of +1 level of diffracted light for pure phase modulation; the modulated diffracted light enters into a planar mirror through vertical incidence and then returns along the original light path, and then enters into the diffraction grating again through incidence to generate secondary diffraction; a secondary +1 level of diffracted light carries the grating displacement information along the opposite direction of the emergent light of the laser and then returns to an cavity in the laser and then laser feedback interference occurs in the cavity between secondary +1 level of diffracted light and the light in the cavity; a photoelectric detector is arranged the backward output light path of the laser; the photoelectric detector is connected with an operational amplifier, a data collection card and a computer successively; and the displacement to be detected can be obtained through processing of the computer. The phase modulation type laser feedback raster interferometer has the advantages of being simple and compact in structure, being large in the measuring range, and being insensitive to the environment.

The invention discloses a method and apparatus of 600-700nm wave range Fourier transform photo-induced luminous spectrum. The apparatus comprises a Fourier transform infrared spectrograph measuring system, a laser used as active light source, a lock-in amplifier which connects the Fourier transform infrared spectrograph detector and the circuit controlling plate and a circuit-breaker on the light path between the sample and the laser, so that it can transfer the constant active light into the modulated active light and feedback it in the reference end of the lock-in amplifier to control the lock-in.

A stress double ¿C refraction double frequency laser with elastic loading is composed of He ¿C Ne laser tube, a pair of laser reflectors, stress double ¿C refraction element, permanent magnet block and elastic force loading mechanism. It features that elastic force loading mechanism is fixed on laser tube and it includes elastic force clamp fixed on anti ¿C reflector and reflector of laser, and stress element with groove for loading force on projection of clear surface.

The invention relates to light-scattering device and method for measuring the diameter and length of a short carbon nano-tube, wherein the method for measuring the diameter and length of a short carbon nano-tube comprises the following steps: the light emitted by a helium-neon laser becomes a linearly-polarized laser in a vertical direction via Glan-Taylor prism; an incident linearly-polarized laser irradiates on particle samples in a sample cell after being reflected by a plane mirror and focused by a lens, the scattered light in a 90-degree direction generated by the sample particles irradiated by the laser beam orderly enters in two faced pores; the scattered light is decomposed into a polarized scattered light in the vertical direction and a polarized scattered light in a horizontal direction via Wollaston prism; and the polarized scattered lights in the two directions are detected by two photomultipliers respectively, and the measured light signal is converted to a TTL (transistor-transistor logic) pulse voltage signal and conveyed in a mathematic correlator to obtain the measured diameter and length. Relative to the most general microscope measuring method at present, the method for measuring the diameter and length of a short carbon nano-tube is a non-contact measuring method, as well as is fast in measuring speed, low in cost and low in operational requirements. Relative to Raman spectrometry, the method for measuring the diameter and length of a short carbon nano-tube can measure diameter and length simultaneously, and is suitable for measurement for multi-wall carbon nano-tube.

The invention discloses a laser wavelength detection control device in TDLAS (Tunable Diode Laser Absorption Spectroscopy) and control method thereof. The device is characterized in that a signal of a near-infrared DFB (Distributed Feed Back) semiconductor laser is input into single mode fiber couplers through a polarization controller, a signal of a helium-neon laser is input into the single mode fiber couplers through the polarization controller, the signals enter piezoelectric ceramic optical-fiber stretchers, are subjected to filtering and then are received by photoelectric detectors, and the photoelectric detectors output the signals to a near-infrared DFB semiconductor laser wavelength measurement and current controller. The method comprises the following steps of: performing length difference modulation on optical fiber arms through a dual-wavelength fiber michelson interferometer structure and the piezoelectric ceramic optical-fiber stretchers, detecting optical-fiber end face Fresnel reflection interference signals by the photoelectric detectors, performing rapid detection on laser wavelength through phase position modulation measurement, and stabilizing output wavelength through controlling the bias current of the near-infrared DFB semiconductor laser. The laser wavelength detection control device and method provided by the invention overcomes the slow drifting and mold skip of an infrared DFB semiconductor laser in a TDLAS system, and is applied to laser measurement fields of laser atmosphere measurement, industry combustion measurement control and the like.

The invention relates to the field of monitoring of smoke particulate matter, in particular to a device and a method for monitoring concentration of ultralow-emission smoke. The concentration monitoring device comprises an angle scattering measurement device, a beta-ray measurement device and a computer, wherein the angle scattering measurement device comprises a helium-neon laser, a laser controller, a temperature control power supply, an aerosol generator, a heating device, a particulate matter measurement zone, a photodetector and a photoelectric converter; the beta-ray measurement device comprises a beta-ray radiation source, a sampling tube, a beta-ray detector and a vacuum pump; the sampling tube is connected with the particulate matter measurement zone and the vacuum pump; the photoelectric converter and the beta-ray detector are connected with the computer; measurement results are transmitted to the computer, the computer corrects an angle scattering measurement result througha beta-ray measurement result, and corrected real-time concentration information of particulate matter is obtained. Accurate real-time measurement result can be obtained with the monitoring method, and the requirements for timeliness and accuracy of smoke measurement can be met simultaneously.

The invention discloses a device for researching pile-soil interaction under horizontal load through transparent soil and a test method of the device. The device comprises a supporting framework and amodel slot placing plate, wherein two slide rails are arranged on a slide rail fixing plate fixed on the supporting framework; the lower surface of the model slot placing plate is fixedly equipped with slide wheels which are matched with the slide rails; a model slot and a limiting device are arranged on the upper surface of the model slot placing plate; a model pile fixing plate is connected onto the supporting framework above the model slot; a mounting hole is formed in the model pile fixing plate; a vibration wire type sensor is mounted on the side surface, approximately perpendicular to the slide rails, of the model pile; a lifting jack for pushing the model slot to slide along the slide rails is mounted on the slide rail fixing plate; a laser light source system is placed on the opposite side of the lifting jack; an image acquisition device for acquiring an image in the model slot is arranged at the perpendicular side of the laser light source system; and the image acquisition device, a helium-neon laser unit, the lifting jack and the vibration wire type sensor are connected with a controller.

The invention provides a method and apparatus for measuring the parallelism of a germanium window plate. The apparatus comprises a helium-neon laser system, an inclination-adjustable platform and a reference plane for receiving the reflected laser and measurement and analysis software thereof. The method includes the steps of gluing the germanium window plate on a photoresist plate and placing on the platform, and adjusting the platform inclination so that the surface of the photoresist is perpendicular to the laser. The parallelism of the upper and lower surfaces of the germanium window is theta = arctan (A / L) / 2, wherein A is the laser reflection offset reflected by the upper surface of the germanium window plate, and L is the distance between the laser receiving plane and the germanium window plate. Visible laser is used to detect the parallelism of infrared germanium window plate. The apparatus has the advantages of relative simple structure and high measurement precision.