106 results about "Self-focusing" patented technology

The invention discloses a light path system based on a gas-filled hollow-core optical fiber, and the system comprises a spectrum broadening device which comprises a first gas extraction chamber, a gas inlet chamber and a second gas extraction chamber, the first gas extraction chamber and the second gas extraction chamber are located at the two ends of the gas inlet chamber respectively, and the first gas extraction chamber and the gas inlet chamber are separated through a first sealing part; the second air exhaust chamber and the air inlet chamber are separated through a second sealing piece; the spectrum broadening device is internally provided with a hollow-core optical fiber and is provided with at least one through hole penetrating through the pipe wall of the hollow-core optical fiber, the two ends of the hollow-core optical fiber penetrate through the first sealing piece and the second sealing piece respectively so that the two ends of the hollow-core optical fiber can be communicated with the first air suction chamber and the second air suction chamber respectively, and the through hole is located in the air inlet chamber. The two ends of the hollow-core optical fiber are subjected to air exhaust, so that the ionization rate and the self-focusing effect generated when the laser is output after the spectrum of the inflated hollow-core optical fiber is broadened can be remarkably reduced, the requirement for improving the power input of the laser is met, and a light path system can bear higher laser monopulse energy compression.

The invention belongs to the technical field of laser vibration measurement, and provides a self-focusing laser Doppler vibration measurement method and system capable of resisting self-vibration of an optical fiber, and the method comprises the steps: adding a compensation light path which is used for sensing and generating reference light which is equal to an interference signal in amplitude and is opposite to the interference signal in real time in a Doppler vibration measurement light path, and taking the minimum mean square error as a self-adaptive matching criterion; interference phases obtained by synchronous demodulation of the compensation light path and the main light path are subjected to adaptive matching and cancellation in amplitude and phase dimensions, residual errors of vibration of the vibration measurement system and other environmental interferences are suppressed below noise of the vibration measurement system, and the purpose of balancing and weakening optical fiber vibration interferences in an instrument is achieved. The influence of the vibration factor of the instrument is reduced, and the interference influence is accurately eliminated through amplitude and phase matching by a demodulation algorithm corresponding to a compensation light path; meanwhile, by dynamically observing and updating the return light intensity threshold, low-frequency disturbance is resisted, and accurate automatic focusing is achieved.

The invention belongs to the technical field of optical measurement, and discloses an implementation device and method of a single-photon spectrograph, and the device comprises a spectral wavelength scanning module which is used for collecting a wide-spectrum optical signal, carrying out the wave division processing, and calculating the photon counting change rate between adjacent wavelengths; wavelength stepping is dynamically adjusted according to the photon counting change rate, self-adaptive scanning of spectrum change is achieved, and a single-spectrum optical signal is output; the self-focusing detection module is used for converting the single-spectrum optical signal into a photon event through a preset array channel; in a preset time window, calculating the variance and the Shannon entropy of each photon event, and constructing a local uncertainty index; performing spectral domain self-focusing and resampling according to the local uncertainty index to obtain photon counting data; high-precision, high-stability and high-efficiency spectrum light signal detection and visual analysis are realized.

The invention discloses an SAR image self-focusing distortion correction method and device, and belongs to the technical field of synthetic aperture radars. The method comprises the following steps: carrying out distance blocking and orientation sub-aperture division on a defocused SAR image, selecting a sample, and carrying out orientation decompression to a phase historical domain; performing azimuth dechirp processing on the sub-aperture data in each distance sub-block, and estimating a phase error through a standard PGA algorithm; after splicing sub-aperture phase errors and removing an overall linear phase, performing phase compensation and azimuth compression to obtain a focused image; and for azimuth distortion caused by residual linear phase of the compensated image, extracting a phase error linear term coefficient through a sliding window, deducing an azimuth shift distance in combination with Fourier transform time shift characteristics, and finally performing shift correction by adopting sinc interpolation. According to the method, the image focusing quality is improved, and meanwhile, the ground feature continuity and the image resolution are kept.

This invention discloses a phase compensation method for ship targets using ISAR based on block phase gradient autofocus. The steps include: pulse compression; range cell migration correction; range-oriented block segmentation; block phase compensation; calculation of the offset between adjacent image blocks; and image block alignment and stitching. This invention performs range-oriented block segmentation of the target echo, overcoming the shortcomings of existing technologies that ignore the spatial variation of rotational phase error, leading to defocusing in ship imaging, thus improving the accuracy of phase compensation and achieving good image focusing effect. Because this invention uses a phase gradient autofocus algorithm to compensate for the phase error within each block, and then uses a cross-correlation method to align and stitch the images of each block region, it overcomes the shortcomings of parameter estimation methods, such as complexity, time consumption, and poor real-time performance, and has the advantages of simple implementation, high efficiency, and strong real-time performance.

The invention relates to the technical field of ultrafast laser, in particular to an ultraviolet laser damage inhibition method and device for a fused quartz optical element, and the method comprises the steps: obtaining oxy-18 modified DKDP crystals with oxy-18 isotope abundance higher than natural abundance; preparing the oxy-18 modified DKDP crystal into a wave plate matched with a preset ultraviolet laser wavelength; in an ultraviolet laser light path of a laser inertial confinement fusion device, a wave plate is arranged between a linear polarization state output end of ultraviolet laser and a fused quartz optical element; and enabling ultraviolet laser to sequentially pass through the linear polarization state output end and the wave plate to form circularly polarized light, and irradiating the circularly polarized light to the fused quartz optical element. The invention aims to realize the small-scale self-focusing effect of actively inhibiting fused quartz and solve the technical problem that a traditional material cannot be used as a large-aperture wave plate due to over-high transverse stimulated Raman scattering.

The application discloses a method for generating an ultralong focal depth array beam, and belongs to the technical field of grating manufacturing. The method comprises the following steps: constructing a Bessel beam excitation phase and a circular Airy beam excitation phase, constructing a composite phase distribution according to the array Bessel beam excitation phase and the array circular Airy beam excitation phase, and encoding the composite phase distribution to a metasurface; irradiating the metasurface with a linear polarization state plane wave, so that a left-handed circular polarization component excites an array Bessel beam, and a right-handed circular polarization component excites an array circular Airy beam; the array circular Airy beam is converted into a Bessel propagation mode after self-focusing, is spliced with the array Bessel beam in an axial direction to form a continuous light field distribution, and an ultralong focal depth array beam is obtained. The method can be applied to the fields of parallel laser processing, three-dimensional microscopic imaging and microparticle manipulation, and can extend the focal depth of the array Bessel beam while keeping the transverse resolution close to the diffraction limit.

The invention discloses a remote high-depth-of-field LIBS self-focusing detection device for a lunar soil environment, and the device comprises a variable-curvature primary mirror which is provided with a central light through hole, and one side of the variable-curvature primary mirror is sequentially provided with a beam expanding assembly, a low-pass dichroscope, a focusing system, and a spectrometer; the multi-secondary-mirror zooming structure is arranged on the other side of the curvature-variable primary mirror; wherein the low-pass dichroscope corresponds to the transmitting end of the pulse laser; the variable-curvature primary mirror comprises a plurality of reflectors which are sequentially stacked from left to right, wherein the curvatures of the reflectors are sequentially increased. The multi-mirror zoom structure comprises a guide rail capable of rotating and axially moving; and the plurality of secondary mirrors with different curvature radiuses are sequentially arranged on the guide rail through the electronic clutch, and the secondary mirrors can diverge and reflect the light beams. According to the invention, the super-large depth of field with the axial depth of 1.5 cm is constructed by using the variable-curvature primary mirror, and the large-range coverage of the full life cycle area of the expanded plasma is realized.

The invention relates to a method for generating self-focusing by a Lorentz non-uniform correlation partially coherent pulse light source, which comprises the following steps of: firstly, by constructing a pulse light source with a Lorentz non-uniform time correlation structure, defining a time domain mutual coherence function of the pulse light source so as to represent pulse coherence characteristics; the mutual coherence function is based on the generalized Huygens-Fresnel principle, a mutual coherence function expression of the LNUC partially coherent pulse light source at the transmission distance z is deduced, and the coherence degree is in Lorentz distribution and has the non-uniform correlation characteristic. An average intensity expression is further obtained according to a mutual dry function expression, intensity distribution has a self-focusing phenomenon in evolution, and the characteristic has potential application value in the fields of pulse beam shaping and micromachining.

A dynamic 3D light scattering particle size distribution measurement device includes a polarization splitter for generating an s laser beam with perpendicular polarization and a p laser beam with parallel polarization that travels parallel to and spaced apart from the s laser beam. A lens is used to focus the s laser beam and the p laser beam onto a common focus area inside a sample holder holding a sample whose particle size is to be measured. An s light intensity detector measures a time-resolved s light intensity from s backscattered light from the focus area. An s-polarisation filter allows perpendicularly polarized light to pass, resulting in s measuring light, and includes a light detector for time-resolved intensity measurements of the s measuring light. A p light intensity detector measures a time-resolved p light intensity detects p backscattered light from the focus area, and includes a p polarization filter that allows parallel polarized light to pass. A light detector provides for time-resolved intensity measurement of the p measuring light, and an evaluation unit automatically calculates the particle size distribution from the time-resolved p light intensity and the time-resolved s light intensity.

This application relates to the field of space imaging technology and provides a method for decoupling translational and rotational motion in space-based microwave imaging of space targets based on parameter estimation. The method first uses adjacent cross-correlation and self-focusing methods to perform preliminary compensation for the translational motion components of the microwave imaging echo data. Then, using the first-order translational motion parameters fitted by the former as initial values ​​and minimizing the image entropy of the echo data as the cost function, it combines Keystone transform to optimize and compensate for the translational linear phase components. Next, it uses Keystone transform to compensate for the spatially varied range cell migration caused by the rotational motion components. Finally, it performs a second compensation for the residual translational motion components, obtaining echo data after almost complete compensation of the translational and rotational MTRC. By performing spatially varied phase error compensation and azimuth compression on this data, the imaging result of the space target can be obtained. This method achieves a balance between the efficiency and accuracy of parameter estimation, effectively improving imaging quality.

The invention relates to a beach vortex light beam pattern recognition method based on cross phases. On the basis of a beach vortex light beam with a self-focusing characteristic, the beach vortex light beam mode identification method based on the cross phase is provided by combining the mode evolution influence of the cross phase on a light field in the transmission process. Conventional single-mode vortex light is in a circular ring shape, the accurate value of the topological charge cannot be accurately distinguished, and the method achieves accurate recognition of the topological charge value of the frontal vortex light beam with the self-focusing characteristic for the first time on the basis of a phase type spatial light modulator and a cross phase. And positive and negative topological charges can be accurately distinguished according to a mode evolution result. Compared with a traditional vortex light field capable of being stably transmitted, the method achieves a good effect in the aspect of detection of the vortex light field with the self-focusing characteristic, belongs to the field of light field regulation and control, and can be applied to design of optical elements.

The invention discloses a satellite-borne SAR (Synthetic Aperture Radar) self-focusing method and system for a long-time integral bunching mode, a computer and a storage medium, and the method comprises the steps: screening a strong scattering target region in a manner of taking the maximum contrast or maximum power as a target according to the size of a divided grid; a minimum entropy distance alignment algorithm based on a partial frequency spectrum is used to realize distance migration error estimation of a partial region, a mode of combining hamp filtering and polynomial fitting is used to realize full-scene distance migration error estimation, and a minimum entropy phase correction algorithm is used to realize phase error estimation of a partial region. All-scene phase error estimation is realized by combining a Savitzky-Golay filter and a polynomial fitting mode, and unified compensation processing is performed on an original all-scene image by applying all-scene range migration errors and a phase error estimation result, so that all-scene fine focusing is realized. According to the invention, large-scene full-image fine focusing under the condition of over 15 seconds of ultra-long synthetic aperture time can be realized.

The application provides a terahertz SAR high-efficiency self-focusing imaging method and system based on RB-PCA, comprising: obtaining original echo signal data and performing pretreatment; performing distance block in the distance direction on the pretreated echo signal data to obtain a plurality of distance blocks, performing sub-aperture segmentation in the distance block for each distance block to obtain a plurality of sub-aperture signal data; performing desquamation processing on each sub-aperture signal data to obtain desquamation signal data; performing PCA processing on the desquamation signal data and selecting a characteristic vector with the largest characteristic value as a target characteristic vector; obtaining each sub-aperture phase error gradient estimation value through adaptive PGA estimation on the target characteristic vector; obtaining two-dimensional space-varying phase errors of each distance block through global splicing and fusion on each sub-aperture phase error gradient estimation value; and performing phase compensation and azimuth compression on the pretreated echo signal data based on the two-dimensional space-varying phase errors to obtain focused imaging results.

The application provides a background ionosphere correction method suitable for high-orbit SAR ground surface coordinate system imaging, which comprises the following steps: receiving a high-orbit SAR echo signal, obtaining corresponding background ionosphere TEC data of the high-orbit SAR echo signal, and performing coarse compensation on the background ionosphere phase error of the echo signal according to the ionosphere TEC data; performing high-orbit SAR ground surface coordinate system imaging on the data after coarse compensation to obtain a large scene image; estimating the phase error of the phase of the echo signal without coarse compensation by using a self-focusing algorithm and the large scene image to obtain an estimation result; fitting the estimation result by using a least square method, determining a coefficient matrix of an ionosphere space-time coupling model corresponding to the large scene image according to the fitting result; dividing the large scene image into a plurality of sub-scene images, performing fine compensation on the background ionosphere phase error of each sub-scene image according to the determined coefficient matrix and each sub-scene image, and completing the correction, so that the correction of the high-orbit SAR ground surface coordinate system imaging is realized.

This invention discloses a self-focusing vortex spin terahertz transmitter and its application, comprising a glass substrate, a spin terahertz thin film, and a magnet pair. The spin terahertz thin film is composed of a ferromagnetic material layer, a heavy metal non-magnetic material layer A, and a heavy metal non-magnetic material layer B. The ferromagnetic material layer is disposed on the upper surface of the glass substrate, and the heavy metal non-magnetic material layers A and B are arranged in a spiral alternating pattern on the outer surface of the ferromagnetic material layer. This invention has a simple structure. By fabricating two specially arranged heavy metal non-magnetic material layers with equal and opposite spin Hall angles on the ferromagnetic material, a spiral spin terahertz Fresnel zone plate is constructed, enabling the generated vortex spin terahertz waves to have a focusing function, thereby improving the integration of the vortex spin terahertz transmitter.

The airborne SAR real-time self-focusing imaging method comprises the following steps: estimating Doppler center frequency based on an amplitude equalization method; iterative calculation: utilizing the estimated Doppler center frequency, introducing a migration parameter correction term delta D (eta) and a frequency modulation correction term delta Km (eta), and recalculating a distance Doppler domain signal of the current iteration round; based on the improved CSA processing chain, performing phase error compensation on each range gate by using a space-variant phase error compensation function to obtain a compensated range Doppler domain signal; carrying out distance direction and azimuth direction compression in parallel to generate a focusing image, and evaluating image quality indexes; if not, extracting strong scattering points, estimating the residual two-dimensional phase error of each range gate, fitting and updating delta D (eta) and delta Km (eta), and carrying out the next round of iterative calculation; and if so, ending iteration, and outputting the focused image of the current round. According to the method, the pixel-by-pixel suppression of motion error correction and space-variant error independent of external sensing and embedded real-time imaging processing are realized.

The invention provides an optical fiber collimator, an MEMS optical acceleration sensor and a preparation method. The optical fiber collimator comprises a self-calibration coupling unit, a self-focusing collimation unit and a light beam steering adjusting unit. The self-calibration coupling unit is provided with an axial inner hole, and the self-focusing collimation unit and the light beam steering adjusting unit are both installed in the axial inner hole and are oppositely arranged. The first end face, facing the self-focusing collimation unit, of the light beam steering adjustment unit is not perpendicular to the axis of the axial inner hole. Light rays incident through the self-focusing collimation unit are reflected by the first end face to be turned and emitted out of the self-calibration coupling unit; the optical fiber collimator integrates the light beam steering and angle adjusting functions, after the system is installed, the direction of the emergent light beam can be optimized in real time by adjusting the light beam steering adjusting unit in the circumferential direction, and the installation difficulty is greatly reduced.

The invention relates to a fluorescence microscopy system comprising a nonlinear optical medium (ML) and comprising: - a laser source (SL) suitable for delivering first laser pulses (IL1) having a first wavelength λ1; - a power optical modulator (MP) suitable for modulating a power of the first laser pulses (IL1) so as to form second laser pulses (IL2) having different optical powers; - said optical medium (MO) being suitable for the second pulses to propagate by undergoing self-focusing within the optical medium so as to define, for each second pulse, a focal point having a longitudinal position in the optical medium that is different from the other second pulses, laser radiation originating from the optical medium and having the second self-focused pulses, referred to as third pulses, being named the output beam (FS); - a microscope (M) suitable for: - collecting a first fluorescence radiation generated via the first wavelength λ1, by illuminating a sample (Ech) with the output beam; then - acquiring, from the first collected fluorescence radiation, at least one image of the sample for each of the third pulses illuminating the sample, each at least one image being associated with a transverse observation plane of the sample that is different from the other images.

The invention belongs to the field of optical fiber lasers, discloses a simulation-based mode field adapter for an optical fiber laser and a preparation method thereof, and is particularly suitable for low-loss coupling from a large-mode-field optical fiber to a single-mode optical fiber of 980nm-band pumping laser. The method comprises the following steps: firstly, optimizing refractive index distribution of a self-focusing optical fiber through optical simulation, determining a period parameter P and verifying that theoretical fundamental mode loss is less than or equal to 0.18 dB; based on this, the length of the self-focusing optical fiber is set to be a half-cycle integral multiple structure (L = n.P + 0.5 P, n > = 1). In an experiment, a thermal core expanding process is combined, and efficient coupling from a large-mode-field optical fiber to a single-mode optical fiber is achieved. According to the scheme, the industrial problem that a traditional adapter is high in loss in the large-to-small mode field direction is solved, and low loss of 0.45 dB is achieved in the 980 nm wave band. And meanwhile, the complex mode field measurement requirement is avoided, and the transmission efficiency of the pumping laser is remarkably improved. The adapter is especially suitable for an optical fiber laser output end coupling scene, and breaks through the limitation that an existing adapter is only suitable for a small-to-large mode field direction.

The present invention provides a device for obtaining data from a sample. This device comprises an external equipment with a laser source, a Raman spectrometer and an external LIBS spectrometer and a handheld probe. An excitation barrel (1) is configured to produce a collimated laser beam, the first folding mirror (2) is arranged to reflect the collimated laser beam and the first dichroic (3) is configured to project the reflected collimated laser beam into a first direction. A LIBS excitation source (6) is configured to produce a pulsed laser beam, a focusable beam expander (7) is configured to produce an expanded laser beam with a modified divergence, so that it focalizes on the same reference plane as the reflected collimated laser beam, the second folding mirror (8) is arranged to reflect the expanded laser beam and the second dichroic (9) is configured to project the reflected expanded laser beam into the first direction. A focuser (4) is arranged in the first direction and is arranged to receive the reflected collimated laser light and the reflected expanded laser beam and focus them on a focusing point contained in the reference plane. The device further comprises a Raman collection barrel (5) and a LIBS collection barrel (10). Finally, an optical component (12) is configured to reflect part of the sample light coming from the focuser (4), a diaphragm (13) is configured to receive the light reflected by the optical component (12) and a camera system is configured to receive the light which passes through the diaphragm (13).

The application discloses a kind of based on the sparse SAR self-focusing imaging method of undersampling echo, comprising: based on the echo data of random undersampling acquisition, construct sparse SAR self-focusing imaging model;Through sparse SAR self-focusing imaging model reconstruction observation scene;The azimuth signal of non-sparse solution of observation scene is FrFT, and rotation angle is updated;Calculate Doppler frequency error, update azimuth matching filter operator, and calculate echo simulation value;According to the value of echo simulation, estimate the sparse solution of observation scene;Repeat iteration until Doppler frequency error is less than the threshold value set, and output focused sparse SAR image.The application combines the Doppler frequency estimation algorithm based on FrFT with the sparse SAR imaging algorithm based on complex approximate information transmission, while solving the sparse solution of observation scene and the non-sparse solution of phase preservation, can effectively estimate the Doppler frequency of random undersampling echo data, obtain focused sparse SAR image.

The application discloses a kind of monolithic integrated outer cold cavity type self-focusing edge-emitting laser array and preparation method, comprising: on the surface of semiconductor epitaxial layer, there are in turn inclined waveguide area, electrically isolated channel and fractional order Talbot cold cavity area;Inclined waveguide area includes a central waveguide and a plurality of inclined waveguides distributed symmetrically on the left and right sides of central waveguide, and the inclination angle of each inclined waveguide is greater than the inclination angle of central waveguide;Fractional order Talbot cold cavity area length meets fractional order Talbot distance, and there is no gain and no loss for the light passing through;One side of the upper surface of inclined waveguide area is provided with high reflectivity DBR grating;One side of the upper surface of fractional order Talbot cold cavity area is provided with semi-reflective semi-transmissive DBR grating.The application effectively improves the coherence of laser array, reduces the loss of fractional order Talbot array in supermode identification process, and realizes high-efficiency high-beam-quality output of laser array.

The application provides a device structure preparation method based on a laser etching process, comprising the following steps: 1) focusing a plurality of laser mother light beams respectively, and then equally dividing the plurality of laser mother light beams into a plurality of laser sub-light beams, and arranging the plurality of laser sub-light beams at equal distances; 2) providing a control module, the control module can independently control each laser sub-light beam; 3) acquiring the actual positions of the laser sub-light beams through a laser marking alignment method, so as to establish a coordinate layer corresponding to the actual positions of each laser sub-light beam in the control module; and 4) based on the coordinate layer, controlling each laser sub-light beam to perform laser etching on a target substrate through the control module, so as to form a required device structure. The application can achieve the purpose of precise etching of light waveguides with different positions and different shapes in a mask-free state through control of a plurality of laser beams, can greatly reduce the cost and improve the etching rate, and can realize precise etching of light waveguides with different depths by changing the types and energy of the laser.

The invention discloses an underwater frontal light beam generation method and system based on blue-green light phased array regulation and control. The method comprises the following steps: S1, generating high-power narrow-linewidth blue-green laser; s2, constructing an optical fiber laser phased array based on the high-power narrow-linewidth blue-green laser; s3, determining the phase distribution of sub-beams required for generating the frontal light beam in the target underwater transmission distance according to the generation mechanism of the frontal light beam; s4, performing active phase regulation and control on each sub-beam in the optical fiber laser phased array according to the phase distribution; s5, coherent combination is carried out on the sub-beams after phase regulation and control through an emission aperture, a high-power beach beam is generated, and when the beach beam is transmitted underwater to the target transmission distance, a central light spot of the beach beam is kept unchanged or has a self-focusing characteristic; through active phase regulation and control and coherent combination based on the optical fiber laser phased array, a high-power frontal light beam with a central light spot kept unchanged or with a self-focusing characteristic is generated at an underwater target distance.

The application discloses a GEO SAR time-varying ionosphere error compensation method based on maximum contrast self-focusing, and belongs to the technical field of GEO SAR (Geosynchronous Earth Orbit Synthetic Aperture Radar). The method selects distance line signals from a GEO SAR image, the distance line signals are the signals with the same distance time in the azimuth direction, the average power of each distance line signal in the image is calculated, a part of the distance line signals are selected, then the contrast of the SAR image is used to iteratively estimate the quadratic phase error coefficient, the cubic phase error coefficient is iteratively estimated based on the quadratic phase error coefficient, and finally the obtained quadratic and cubic phase error coefficients are used for phase compensation of the original SAR image, so that the SAR image affected by the time-varying ionosphere is accurately compensated. Experiments prove that the contrast of the compensated SAR image is improved by the method, and the compensated image is good, and is close to the image not affected by the time-varying ionosphere.

The invention provides a microchannel plate for cathode electron self-focusing in a photocathode X-ray tube and a use method. A micro-channel plate is applied to the technical field of high-performance X-ray tubes, a substrate is a physical substrate of the micro-channel plate and is of a Fresnel lens structure, and the substrate is provided with a plane incident plane and a distorted surface output plane formed by concentric annular belts; a gradient aperture array is distributed on the substrate, and the gradient aperture array is arranged on the plane of the substrate; the radial gradient material is a surface functional coating of the inner wall of the micro-channel; the variable aperture channel is an inner wall surface three-dimensional contour of each independent micro-channel forming the gradient aperture array, and each independent micro-channel in the gradient aperture array is defined. Different secondary electron emission materials are coated on the surface of the inner wall of each micro-channel defined by the gradient aperture array in a partitioned manner along the radial direction. In this way, the problems that in the prior art, an X-ray tube is loose in structure and poor in performance can be solved.

The application provides a high-energy ultrafast laser amplification system and a design method thereof. The physical characteristics of the self-focusing phenomenon are utilized, a self-focusing component is designed to expand the spot diameter, the focus position of the self-focusing is ensured to be outside the laser crystal, and the damage inside the laser crystal is avoided. In addition, by determining the parameters of the seed light source, the laser crystal and the pump light source first, and then backstepping the parameters of the beam expander, the design of the entire system can be conveniently and quickly completed, repeated adjustment of various devices and repeated experimental tests are avoided, and the design and manufacturing efficiency is improved.

The application discloses a high-definition digestive tract endoscope based on convection heat exchange, which comprises a high-definition equivalent prism module, a self-focusing introduction joint, a self-focusing illumination light transmission system and an air convection heat exchange system; the center line of the lens group in the 3D high-definition equivalent prism module is perpendicular to the right-angle input surface of the equivalent prism, and does not pass through the center of the right-angle input surface of the equivalent prism, thereby solving the problem of 3D image linearization between object space and image space; the self-focusing illumination light transmission system improves the transmission efficiency of the illumination light and the free space rate in the inner cavity of the insertion part; the air convection heat exchange system transports air to the insertion part head end and the operating handle of the high-definition digestive tract endoscope, respectively carries away the heat generated by the high-definition imaging chip, the signal processing circuit board and the illumination light in the homogenizing lens group through the convection mode, and makes the air leave the high-definition digestive tract endoscope through the primary and secondary control valves.

The invention relates to the technical field of transducers, and discloses a high-strength self-focusing ultrasonic transducer which comprises a plurality of mutually independent fan-shaped transducer assemblies, all the fan-shaped transducer assemblies are annularly arrayed along the same axis to form an annular concave spherical surface, and each assembly is provided with a fan-shaped transducer base, a fan-shaped transducer unit and an adjusting mechanism. One end of the fan-shaped transducer unit is connected with the fan-shaped transducer base through a pin shaft, the other end of the fan-shaped transducer unit is connected with the adjusting mechanism, and the adjusting mechanism can drive the fan-shaped transducer unit to rotate around the pin shaft to enable the radius of the concave spherical surface to change dynamically. According to the invention, sound waves can be guided to be efficiently converged in a treatment target area, the utilization efficiency of sound energy is improved, the focal nucleus parameters can be flexibly regulated and controlled to solve the problem that the focal nucleus of the traditional transducer is fixed, each fan-shaped transducer assembly can be independently regulated and controlled, the tumor cell killing effect is finally promoted, and the clinical application range is expanded.