12 results about "Spatial dispersion" patented technology

The invention relates to a chip temperature measurement and morphology synchronous in-situ monitoring system based on femtosecond laser, and the method comprises the steps: employing a femtosecond laser, a time dispersion unit, a non-polarization beam splitter, a space dispersion assembly, a focusing unit, and a MHz-level and above high-speed free space photoelectric detector; the femtosecond laser pulse is subjected to time domain and space transformation by components such as a MHz-level and above high-speed digital oscilloscope and a computer, and the transient temperature and morphology change of the surface of the chip can be obtained by combining data processing methods such as Hilbert transformation. Therefore, the problem that MHz-level synchronous ultrafast temperature measurement and imaging of the chip cannot be realized in the prior art is solved.

The application provides a device and a method for fast non-destructive non-contact measurement of internal strain of silicon material, comprising: a near-infrared femtosecond laser for generating a near-infrared femtosecond laser pulse; a time-domain stretching assembly connected with the near-infrared femtosecond laser; an optical signal amplification assembly connected with the time-domain stretching assembly; a first spatial dispersion assembly arranged on an outgoing light path of the optical signal amplification assembly; a microscopic objective lens arranged on an outgoing light path of the spatial dispersion assembly; a second spatial dispersion assembly arranged on an outgoing light path of the microscopic objective lens; a high-speed photoelectric detector located on the outgoing light path of the second spatial dispersion assembly; a high-speed oscilloscope electrically connected with the high-speed photoelectric detector; and a data processing device electrically connected with the high-speed oscilloscope and used for processing and calculating an analog electric signal obtained by sampling to obtain internal strain of a sample to be measured. The application is used for solving the problems of strong dependence on speckle and low detection frame number in the prior art.

The present invention belongs to the field of imaging technology and discloses a two-dimensional spatial framing imaging system, comprising a first cylindrical mirror, a spatial dispersion unit, a reflector unit, a second cylindrical mirror, and an imaging lens. Light beams of different wavelengths pass through the first cylindrical mirror and are incident on the spatial dispersion unit, which spatially disperses the incident light beams to obtain a sub-pulse array arranged in m columns and n rows in a two-dimensional space. The reflector unit includes m reflectors arranged separately in space, and each column of light beams is reflected by a different reflector. After reflection, each column of light beams is incident on the second cylindrical mirror. After being focused by the second cylindrical mirror, each column of light beams is incident on the imaging lens. The present invention can effectively increase the number of frames of framing imaging, while making each column of images clearer, thereby improving the resolution of the two-dimensional spatial framing imaging system.

The invention discloses a metasurface device for high-dimensional light field detection and a detection method of the metasurface device, and belongs to a light field detection technology. According to the metasurface device, a sub-wavelength slit array structure arranged along an Archimedes spiral line is etched on a metal film, and a transmission phase related to frequency and a geometric phase related to polarization are decoupled by utilizing the spatial dispersion and frequency dispersion characteristics of the array structure; therefore, the frequency and the polarization of the incident light are mapped to the topological charge and the composition coefficient of the plasmon vortex light. Through cooperation of the metasurface device and the neural network, the incident frequency and polarization information of the light field to be measured can be accurately extracted from the vortex light interference pattern, and synchronous analysis of multi-dimensional parameters of the light field is realized. The metasurface device not only can cover visible light, near-infrared and terahertz wave bands and even microwave wave bands, but also can extract multi-dimensional information of a light field, can realize accurate regulation and control of the light field on a micron scale through monolithic integration, and provides a solution for a compact optical system.

The invention provides a folding type miniaturized fiber bragg grating demodulation system, and relates to the technical field of miniature fiber bragg grating demodulation systems.The folding type miniaturized fiber bragg grating demodulation system is constructed, the optical design theory, the grating diffraction principle and the high-performance detection technology are fused, and a compact and efficient optical path structure is achieved; accurate grating parameter calculation and spatial dispersion mapping methods are utilized to ensure accurate positioning of spatial distribution of diffracted light, and the resolution and stability of wavelength demodulation are improved; by combining the comprehensive design of the diffraction limit resolution and the pixel limit resolution, parameters of an optical element and a detector are scientifically matched, and high sensitivity and high precision of the system are ensured; the optical path parameters are iteratively optimized through a simulation optimization algorithm, the imaging quality and the system stability are improved, miniaturization and integration of the optical system are achieved, and the system is more suitable for scenes such as laboratory development and teaching experiments.

The present application relates to a kind of adaptive cutting method and system based on femtosecond laser applied to the technical field of laser precision machining, method includes: the thickness parameter of the material to be cut is obtained and compared with predetermined threshold;If thickness is greater than threshold, control optical system directs laser to beisel optical system and carries out longitudinal cutting;If thickness is less than or equal to threshold, it is guided to time compression and spatial dispersion system and carries out transverse cutting.System includes femtosecond laser, longitudinal and transverse cutting optical system, beisel optical system, time compression and spatial dispersion system and controller.The present application solves the technical contradiction that single system cannot consider longitudinal cutting of thick material and transverse precision cutting of thin material by integrating two sets of optical systems and adaptive switching, realizes high-quality "one-key" processing of brittle hard material from micrometer level to centimeter level thickness.

The present invention relates to the field of photoelectric detection technology, and discloses a non-line-of-sight imaging system and method based on spectral and temporal dual coding. A wide-spectrum pulse laser emits laser light, which is processed to output a discrete pulse sequence. The discrete pulse sequence is processed to obtain linearly polarized light in the reflection direction, and the linearly polarized light in the reflection direction is dispersed to output multiple light beams. The multiple light beams are diffusely reflected on the surface of a relay wall and irradiate the surface of a hidden object, and then reflected back to the surface of the relay wall. The non-line-of-sight triple echo light beams that are diffusely reflected again on the surface of the relay wall are collected by a detector through a spatial dispersion element. The required imaging information is then calculated by a processing unit. The present invention introduces spectral and temporal dual coding, and uses time coding and space coding to simultaneously encode the spatial position information of the irradiation point and the photon flight time information in the time domain of the non-line-of-sight triple echo, thereby realizing non-line-of-sight imaging. The system has the advantages of fast and scanning-free operation, high integration, and high reconstruction accuracy.

The invention relates to a femtosecond laser-based temperature measurement and morphology synchronous in-situ monitoring system for a light-transmitting object. The method comprises the following steps: utilizing a femtosecond pulse laser, a time domain stretching assembly, an optical signal amplification assembly, a non-polarization beam splitter, a time delay assembly, a first spatial dispersion assembly, a second spatial dispersion assembly, a first microscope objective, a second microscope objective and a high-speed photoelectric detector; a high-speed oscilloscope, a computer and other components carry out time domain and space transformation on femtosecond laser pulses, and by combining data processing methods such as Hilbert transformation and the like, transient temperature and morphology changes of the light-transmitting object can be obtained. Therefore, the problem that MHz-level synchronous ultrafast temperature measurement and imaging of a light-transmitting object cannot be realized in the prior art is solved.

This invention provides a rapid, non-destructive, and non-contact device and method for measuring strain on silicon surfaces, comprising: a femtosecond laser for generating femtosecond laser pulses; a time-domain stretching component disposed in the output optical path of the femtosecond laser; an optical signal amplification component disposed in the output optical path of the time-domain stretching component; a beam splitter located in the output optical path of the optical signal amplification component, for splitting the femtosecond laser pulses into a test beam and a reference beam with a specific power ratio; a spatial dispersion component disposed in the output optical path of the test beam of the beam splitter; a microscope objective disposed in the output optical path of the spatial dispersion component; a high-speed photodetector located in the output optical path of the reference beam of the beam splitter; a high-speed oscilloscope electrically connected to the high-speed photodetector; and a data processing device electrically connected to the high-speed oscilloscope. This invention addresses the problems of strong dependence on speckle and low detection frame rate in existing technologies.

The invention relates to a self-adaptive cutting method and system based on femtosecond laser applied to the technical field of laser precision machining. The method comprises the steps that the thickness parameter of a to-be-cut material is obtained and compared with a preset threshold value; if the thickness is larger than the threshold value, an optical system is controlled to guide laser to a Bessel optical system for longitudinal cutting; and if the thickness is smaller than or equal to the threshold value, guiding to a time compression and space dispersion system for transverse cutting. The system comprises a femtosecond laser, a longitudinal and transverse cutting optical system, a Bessel optical system, a time compression and space dispersion system and a controller. Two sets of optical systems are integrated and switched in a self-adaptive mode, the technical contradiction that a single system cannot give consideration to longitudinal cutting of thick materials and transverse precision cutting of thin materials is solved, and high-quality one-key type machining of brittle and hard materials with the thickness ranging from the micron level to the centimeter level is achieved.

The application provides a polarization-independent BIC metal super surface optical edge detection device and a design method, the method shows a simple and easy-to-process metal super surface, the device can realize high-quality polarization-independent two-dimensional optical edge detection with high numerical aperture and high efficiency. The design scheme provided by the method takes silicon dioxide as a substrate and C4 symmetric L-shaped aluminum metal patch as a basic unit, adjusts and controls the spatial dispersion of BIC by fine-tuning the perturbation parameters of the super surface, and realizes the polarization-independent second-order spatial differential operation. The design scheme works at a frequency of 0.6718 THz, the numerical aperture (NA) can be as high as 0.56, the peak efficiency can be as high as 36%, and the high-quality edge detection performance can be maintained. The work can realize compact, low-power and ultrafast optical edge detection, and shows great potential in various applications such as optical imaging and computer vision.

The invention belongs to the related technical field of laser modulation, and discloses a laser regulation and control device capable of realizing time dispersion compensation and ophthalmologic operation equipment, the laser regulation and control device comprises a spectroscope, a time dispersion compensation assembly and a space dispersion assembly; when the first polarized light enters the spectroscope, the first polarized light is output towards a first direction through the spectroscope and then is transmitted to the time dispersion compensation assembly, and the time dispersion compensation assembly is used for changing the polarization direction of the first polarized light and enabling a light beam to have time dispersion and outputting second polarized light; the second polarized light is output towards a second direction through the spectroscope and then is transmitted to the spatial dispersion assembly, the spatial dispersion assembly outputs target parallel light beams with spatial dispersion, and the time dispersion caused by the spatial dispersion assembly is compensated by the time dispersion introduced by the time dispersion compensation assembly. Space-time focusing can be realized, time dispersion caused by space-time focusing can be compensated, laser focus pulse width is reduced, focus energy is guaranteed, and cutting efficiency and precision are improved.