Abstract: Disclosed is ultrafast photographing apparatus based on polarization-time mapping, which can obtain spatiotemporal (x, y, t) information of a dynamic scene by means of single exposure. The apparatus includes an active illumination system, a synchronous control system, a data acquisition system, and a data reconstruction system. Firstly, illumination light is generated by the active illumination system to irradiate on a dynamic scene; the synchronous control system is configured to control the single exposure of a camera; the data acquisition system is configured to acquire a two-dimensional image containing sixteen frames of spatiotemporal aliasing by means of polarization modulation and polarization filtering; and the data reconstruction system is configured to reconstruct the acquired image by using an iterative Tikhonov regularization algorithm, and finally to restore sixteen frames of original dynamic scenes with time series information.

Abstract: A method for preparing a graphene based composite wave-absorbing material includes: dissolving a water soluble barium salt and a water soluble iron salt into deionized water, respectively; mixing barium salt solution and iron salt solution according to a molar ratio of Ba:Fe of 1:12 to obtain a precursor solution; dispersing a graphene material in deionized water to form a graphene dispersion; adding citric acid, nitric acid and the graphene dispersion into the precursor solution in sequence to form a mixture solution; stirring the mixture solution at a temperature of 50 to 75° C. to obtain a sol; coating and drying aged sol on a substrate to obtain a coating layer; and sintering the coating layer by a laser irradiation.

Abstract: An automatic photocurrent spectrum measurement system based on a Fourier infrared spectrometer, including a light source component, an environment control component, a measuring module, and a control module. The system is configured to evaluate photoelectric performance semiconductor materials or devices under different temperatures, voltage biases or current biases.

Abstract: Provided is a method for preparing a graphene material from an industrial hemp material by laser induction, which uses a skin, a stem and/or a root of industrial hemp as a carbon precursor-containing material and reduce the carbon precursor-containing material into graphene by laser induction, so as to prepare graphene, graphene quantum dots, a graphene mesoporous material and a graphene composite material.

Abstract: Disclosed is an automatic generation method of a fine-labeled digital pathological data set based on hyperspectral imaging, comprising following steps: obtaining reference histological stained slides and double-stained slides based on pathological samples; obtaining two-dimensional color reference whole slide images based on the reference histological stained slides, and obtaining double-stained hyperspectral images based on the double-stained slides; establishing virtual staining models based on the two-dimensional color reference whole slide images and the double-stained hyperspectral images; establishing a segmentation model for automatically generating labeling information based on the double-stained hyperspectral images; and obtaining the fine-labeled digital pathological data set based on the double-stained hyperspectral images and the virtual staining models, the double-stained hyperspectral images and the segmentation model.

Abstract: Disclosed in the present invention are a functionalized fluoroalkyl silane compound and a synthetic method therefor. The method comprises: dissolving a halosilane and a fluoroalkyl source in an organic solvent; and synthesizing functionalized fluoroalkyl silane under the effect of an alkali or a tertiary phosphine compound. The functionalized fluoroalkyl silane can not only be used for constructing a series of high added-value compounds such as fluoroalkyl substituted alcohols, ketones and amines that can be constructed by conventional TMSRf, but also can transfer, by means of appropriate conversion, a functional group on a silicon protecting group to the obtained addition product in an addition reaction, for synthesizing some fluorine-containing compounds that cannot be synthesized by using a conventional TMSRf reagent, thereby greatly improving the synthesis efficiency and the atom economy of reactions.

Abstract: Provided are a time and frequency control method and system for optical comb. The method includes: controlling an optical comb measuring system to start and to generate an optical comb; obtaining monitoring data, wherein the monitoring data comprises a working temperature, a mode-locked frequency and a light pump power, wherein the mode-locked frequency comprises a repetition frequency and a carrier envelope phase locked at the end of starting the optical comb measuring system; determining whether an offset of the mode-locked frequency exceeds a self-feedback adjustment range of a hardware adjustment circuit; and in response to any of the repetition frequency and the carrier envelope phase exceeds the self-feedback adjustment range, adjusting the working temperature and the light pump power until the mode-locked frequency returns back into the self-feedback adjustment range.

Abstract: Provided is a system for measuring gas temperature and component concentrations in a combustion field based on optical comb. The system includes two pulse laser devices, two continuous laser devices, a beam splitting device, a measurement path, an interference signal detecting device, an optical processing and electrical processing device and a signal acquisition and analysis device. The measurement path refers to the combustion field to be measured. The interference signal detecting device outputs an interference signal. The optical processing and electrical processing device includes several optic elements and electrical elements, and outputs an adaptive compensation signal and an asynchronous sampling clock signal after a series of processing on output of the two pulse laser devices and two continuous laser devices. The signal acquisition and analysis device outputs the measurement result based on the adaptive compensation signal, the asynchronous sampling clock signal and a stable interference signal.

Abstract: The present disclosure provides a stealth dicing method and apparatus. With the method, the focusing element focuses the laser beam on the surface of material to be diced, and the dynamic-equilibrium plasma channel is formed in the material to be diced by means of self-focusing and defocusing effect of plasma generated by ionizing the material to be diced. The modified layer may be formed in the material to be diced throughout the plasma channel, so as to realize stealth dicing.

Abstract: The present disclosure relates to a gain optical fiber heat-dissipating device for high power ultra-fast laser, including a gain optical fiber and a heat-dissipating structure. The heat-dissipating structure includes a metal tube, a flexible heat-conducting layer and a water-cooling structure. The gain optical fiber is passed through the metal tube, and the flexible heat-conducting layer is provided between the metal tube and the gain optical fiber. The water-cooling structure is provided on the metal tube to reduce temperature of the gain optical fiber. The gain optical fiber heat-dissipating device according to the present disclosure can dissipate the heat through a water-cooling mode, and realize rapid heat dissipation, thus improving heat-dissipating efficiency.

Abstract: The present invention discloses a method of species identification and quality detection of liquid-like samples based on nuclear magnetic resonance technology. In this invention, a two-dimensional relaxation signal containing the 1H T1 and T2 relaxation properties of liquid-like samples is obtained by applying a specially designed composite pulse sequence to liquid-like samples, and a fingerprint spectrum from this signal is established. The fingerprint spectrum can be associated with the essential characteristics of the tested sample, thus can be used to distinguish a specific liquid-like sample from the others. The fingerprint spectrum can be easily converted into a digital form, which is not only suitable for constructing big data of fingerprint spectrum for liquid-like samples, but also can be used for quality detection and authenticity judgment of liquid-like samples based on artificial intelligence.

Abstract: A silicon nitride phased array chip based on a suspended waveguide structure, which includes a silicon nitride waveguide area and a suspended waveguide area. The silicon nitride waveguide area includes a silicon substrate, a silicon dioxide buffer layer, a silicon dioxide cladding layer and a silicon nitride waveguide-based core layer. The silicon nitride waveguide-based core layer includes an optical splitter unit, a first curved waveguide, a thermo-optic phase shifter and a spot-size converter. The suspended waveguide area includes a second curved waveguide and an array grating antenna.

Abstract: A single-mode micro-laser based on a single whispering gallery mode optical microcavity and a preparation method thereof described includes: preparing a desired single whispering gallery mode optical microcavity doped with rare earth ions or containing a gain material such as quantum dots, wherein an optical microcavity configuration include a micro-disk cavity, a ring-shaped microcavity, and a racetrack-shaped microcavity; a material type include lithium niobate, silicon dioxide, silicon nitride, etc.; preparing an optical fiber cone or an optical waveguide of a required size which can excite high-order modes of the optical microcavity, such as a ridge waveguide and a circular waveguides; and coupling, integrating, and packaging the optical fiber cone or the optical waveguide with the microcavity. A pump light is coupled to the optical fiber cone or the optical waveguide to excite a compound mode with a polygonal configuration.

Abstract: A Raman spectrometric imaging method, including: placing a sample on a two-dimensional translation stage; emitting a first light beam by a first optical comb light source; dividing the first light beam into a pump light beam and a depletion light beam to illuminate the sample; guiding the pump light beam to illuminate a region of the sample to excite molecules of the sample in the region; guiding the depletion light beam to the region of the sample to make excited molecules at a periphery of the region to return into a vibrational ground state; emitting a second light beam as a probe light beam by a second optical comb light source to the remaining excited molecules to generate a CARS signal; recording the CARS signal for imaging; moving the two-dimensional translation stage to scan other regions of the sample to form an image of the sample.

Abstract: A three-port silicon beam splitter chip includes an input waveguide, three output waveguides, and a coupling region disposed between the input waveguide and the output waveguides and being in a square shape. The input waveguide and the output waveguide have a same width K, where 490 nm<K<510 nm, the coupling region, the input waveguide and the output waveguide have a same thickness H, where 210 nm<H<230 nm, and the coupling region has a length L, where 1600 nm<L<2000 nm. The three-port silicon beam splitter chip of the present disclosure has a high integration degree and a small size, and is capable of improving the portability of the wavefront reconstruction device.

Abstract: Disclosed are a method for preparing a ceramic material including a compound of a formula of A2BxOy and a ceramic material prepared by the method. The method includes: mixing a first oxide of AOm and a second oxide of BOn to obtain a mixture, ball-milling the mixture until a particle size of the mixture is not greater than 1 ?m with a medium selected from a group consisting of ethanol, acetone, deionized water and a combination thereof, to obtain a powder, drying the powder at a temperature in a range of 60 to 80° C., and sintering the powder with a laser irradiation having a laser wavelength of 980 nm, an irradiation power ranging from 50 to 1500 W and an irradiation period of 3 s to 8 min to obtain the ceramic material.

Abstract: The present disclosure discloses a method and apparatus for manufacturing a microfluidic chip with a femtosecond plasma grating. The method is characterized in that two or more beams of femtosecond pulse laser act on quartz glass together at a certain included angle and converge in the quartz glass, and when pulses achieve synchronization in time domain, the two optical pulses interfere; Benefited by constraint of an interference field, only one optical filament is formed in one interference period; and numbers of optical filaments are arranged equidistantly in space to form the plasma grating. The apparatus for manufacturing the microfluidic chip includes a plasma grating optical path, a microchannel processing platform, and a hydrofluoric acid ultrasonic cell.

Abstract: A method for detecting and defending against abnormal traffic of an in-vehicle network based on information entropy, including the following steps: step 1: setting a sliding window; step 2: setting a threshold; step 3: collecting and processing traffic; step 4: calculating information entropy in the sliding window when the window is full; and step 5: detecting traffic of a controller area network (CAN) bus and an in-vehicle Ethernet. Based on impact of abnormal traffic on the information entropy, the information entropy in the sliding window is calculated in real time and compared with the preset thresholds, to detect whether an abnormality occurs.

Abstract: The present disclosure provides a compressed ultrafast imaging velocity interferometer system for any reflector, comprising a light source and target system, an etalon interference system, a compressed ultrafast imaging system, a timing control system and a data processing system. An imaging device in the traditional imaging velocity interferometer system for any reflector is replaced by a compressed ultrafast imaging system, a compressed ultrafast Photography (CUP) is introduced in an imaging process, multi-frame images, i.e.

Abstract: Provided is a method for preparing a graphene-copper calcium titanate CCTO based ceramic composite dielectric material, which includes: dissolving metal ion sources in respective solvents to obtain respective solutions, and mixing the solutions evenly to obtain a precursor collosol of the CCTO based ceramic; allowing the precursor collosol of the CCTO based ceramic to stand for aging, followed by adding a graphene oxide dispersion to mix with the precursor collosol evenly, drying the resulting mixture to obtain dry precursor powders of the graphene-CCTO based ceramic, which are then grinded into fine powders, followed by irradiating by a low-power laser to obtain graphene-CCTO based ceramic composite powders; and compacting and molding the graphene-CCTO based ceramic composite powders, followed by catalytic synthesis with a high-power laser to obtain the graphene-CCTO based ceramic composite dielectric material.