908 results about "Photodetection" patented technology

The invention relates to the technical field of crystal material preparation, in particular to a ternary layered selenide Ge3Sb4Se7 semiconductor material and a preparation method thereof. The preparation method of the ternary layered selenide Ge3Sb4Se7 semiconductor material comprises the following steps that S001, germanium powder, antimony powder and selenium powder with the molar ratio being 3: 4: 7 serve as raw materials, the temperature is increased to 900-950 DEG C under the vacuum condition, and heat preservation is conducted for 12-24 h at the temperature; s002, after heat preservation is finished, the temperature is reduced to 475-500 DEG C at the cooling rate of 1-5 DEG C / min, and heat preservation is conducted for 3-5 days at the temperature; and after heat preservation is finished, furnace cooling or quenching cooling is performed to reach the room temperature, and the layered ternary selenide single-phase material with the chemical formula being Ge3Sb4Se7 is obtained. The ternary layered selenide Ge3Sb4Se7 semiconductor material prepared by the invention is a single-phase material and has the characteristics of low thermal conductivity and low resistivity, so that the ternary layered selenide Ge3Sb4Se7 semiconductor material has application potential in the fields of thermoelectric devices, photoelectric detection and the like.

The embodiment of the invention provides an optical detection device which comprises an imaging assembly and a photoelectric detection device, and the imaging assembly is used for forming an image on an image plane of a to-be-detected area of a wafer. And the photoelectric detection device is used for receiving images and is arranged at the image plane. The photoelectric detection device comprises a light beam separation assembly and a sensor assembly, the light beam separation assembly is used for dividing a continuous first light signal in an image into multiple beams of second light signals, and the light beam separation assembly comprises a microlens array. The sensor assembly is used for receiving multiple beams of second optical signals, and each pixel unit of each sensor in the sensor assembly is used for receiving one beam of second optical signal in the multiple beams of second optical signals. The sensor assembly comprises a single-pixel sensor, and the single-pixel sensor corresponds to one micro lens in the micro lens array; and / or, the sensor assembly comprises a multi-pixel sensor, the multi-pixel sensor corresponds to a plurality of microlenses in the microlens array, and spatial segmentation is beneficial to improving the signal-to-noise ratio.

Various structures for a hybrid pixel array are disclosed. The hybrid pixel array includes a combination of square photodiode (PD) pixel structures and split PD pixel structures. Square PD pixel structures include one photodiode per pixel unit while split PD pixel structures include two photodiodes per pixel unit. In certain instances, square PD pixel structures are used for green light pixels and split PD pixel structures are used for blue and red light pixels in the hybrid pixel array. The combination of square PD pixel structures and split PD pixel structures provides autofocus capability with higher signal strengths. Various techniques for row addressing and readout from the hybrid pixel array are also disclosed.

The invention discloses a multi-core optical fiber multichannel demodulation system for three-dimensional displacement measurement of a mechanical oscillator, which comprises a light source module, a multi-core optical fiber sensing probe, a photoelectric detection module and a signal processing module. A mapping model between multi-channel optical signals and displacement is established, decoupling and high-precision measurement of three-dimensional displacement are realized through a matrix demodulation algorithm, the system takes a multi-core optical fiber as an integrated probe structure, free space optical path alignment is not needed, an optical path is stable, and packaging is simple and convenient; compared with a traditional single-core optical fiber displacement sensing scheme, displacement components of the mechanical oscillator in the three orthogonal directions can be obtained at the same time, and the method has the advantages of being high in measurement precision, high in anti-interference capacity, good in real-time performance, compact in system structure and the like and can be widely applied to the fields of mechanical oscillator displacement measurement, structure health monitoring, precision manufacturing, micro-nano operation positioning and the like.

The invention discloses a reconstruction spectral imaging system based on an electromagnetic drive Fabry-Perot resonant cavity, and belongs to the field of spectral imaging. The system comprises an optical lens group, an electromagnetic driving device, a Fabry-Perot resonant cavity, a photoelectric detection array and a calculation unit, the cavity length of the Fabry-Perot resonant cavity can be adjusted through the electromagnetic driving device. The optical lens group receives light reflected or emitted by an external to-be-measured target scene and carries out collimation processing, and then the light enters the Fabry-Perot resonant cavity. The Fabry-Perot resonant cavity screens the incident light based on the resonance condition of the cavity length of the Fabry-Perot resonant cavity, and the screened light is emitted to the photoelectric detection array; the photoelectric detection array converts the incident light intensity into an electric signal and outputs the electric signal to the calculation unit; and a spectrum reconstruction model is built in the calculation unit, and a hyperspectral image of the to-be-measured target scene is obtained by using the spectrum reconstruction model based on the electric signal. The working range and the spectral imaging precision of the spectral imaging system based on the Fabry-Perot resonator are improved, the technological requirements are reduced, and the engineering applicability of the spectral imaging system based on the Fabry-Perot resonator is improved.

The embodiment of the invention is suitable for the technical field of detection, and provides a pulse processing circuit and method, a sensor and electronic equipment, the pulse processing circuit is configured to be connected with a photoelectric detector, the photoelectric detector comprises at least one photoelectric detection unit, and the photoelectric detection unit is used for outputting a digital pulse signal for a detected single photon; the pulse processing circuit comprises a pulse response module which is connected with at least one photoelectric detection unit and is configured to output a neural network input pulse signal corresponding to the photoelectric detection unit under the condition that a digital pulse signal is received; the neural network module is connected with the pulse response module and is configured to respond to neural network input pulse signals at different moments, generate feature data and output the feature data; the feature data is used for generating a detection result. According to the embodiment of the invention, the feature data can be extracted on the premise that the digital pulse signal does not need to be stored, and the data output quantity is effectively reduced.

The invention discloses an airborne low-detectability photoelectric long-distance stable tracking and aiming method based on a time-sensitive opposite target, and belongs to the technical field of airborne photoelectric detection and target tracking. The method comprises the following steps: step 1, target detection and miss distance calculation: in a level flight section of an airplane, imaging a target in a field of view, carrying out target detection by adopting an optical flow method, and detecting a moving target by analyzing a motion vector of pixel points in an image sequence; and resolving the deviation amount of the target image relative to the visual axis in real time, namely the target pixel miss distance. 2, designing a stable tracking loop: designing a two-layer control structure for the stable tracking loop, stably inhibiting high-frequency disturbance by a gyroscope of an inner loop, performing tracking correction on low-frequency deviation by an outer loop based on pixel miss distance, and finally realizing high-precision tracking. On the basis of real-time pixel miss distance feedback, a two-layer control structure is designed, the miss distance fed back by an outer ring tracking loop is converted into an inner ring control instruction, and the tracking precision and stability are improved.

The embodiment of the invention provides a photoelectric detection device and an optical detection device. The photoelectric detection device comprises a light beam separation assembly and a sensor assembly. The light beam separating assembly is used for separating the first light signal into a plurality of beams of second light signals. The sensor assembly is used for receiving multiple beams of second optical signals. The sensor assembly includes a plurality of sensors, the plurality of sensors including a multi-pixel sensor. The continuous first optical signal is divided into a plurality of small discrete second optical signals through the light beam separation assembly, so that the light sensing area of each sensor corresponding to a sample is further reduced, the haze noise on a single sensor is further reduced through the small light sensing area, and the haze noise on the single sensor is further reduced under the condition that the original first optical signal is not changed. Noise on a single sensor is reduced, and the signal-to-noise ratio of the photoelectric detection device is improved.

The invention belongs to the technical field of photoelectric detection, and discloses a molybdenum ditelluride / nickel ditelluride heterojunction-based photoelectric detector and a preparation method and application thereof, and the molybdenum ditelluride / nickel ditelluride heterojunction-based photoelectric detector is prepared by stripping single crystal molybdenum ditelluride onto an oxide layer silicon substrate through a mechanical stripping method to obtain a molybdenum ditelluride nanosheet; a nickel ditelluride nanosheet is obtained through a chemical vapor deposition method; the molybdenum ditelluride nanosheet is transferred to the nickel ditelluride nanosheet through a PVA dry transfer method to form an overlapped part, and a molybdenum ditelluride / nickel ditelluride heterojunction is formed; and preparing electrodes at two ends of the molybdenum ditelluride / nickel ditelluride heterojunction through electron beam evaporation or thermal evaporation. The photoelectric detector utilizes a built-in electric field generated by a two-dimensional material heterojunction interface to effectively improve the photoelectric conversion efficiency and response speed of a visible light wave band.

The invention relates to the technical field of quantum sensing, and discloses a quantum magnetometer device based on diamond NV color center photoelectric detection magnetic resonance. Wherein the optical path module performs optical excitation and imaging positioning on a diamond sample through a laser and an objective lens. The circuit module integrates a microwave source, a lock-in amplifier, a low-noise current amplifier and a programmable power supply, applies a microwave field and bias voltage to a microwave antenna and an interdigital electrode on the surface of a sample respectively, and collects sample dependency photocurrent signals. And the operation module realizes automatic control and data processing of the system. According to the device, NV color center spin state information is converted into a photocurrent signal through a photoelectric detection magnetic resonance mechanism, an amplitude or frequency modulated signal is demodulated by using a lock-in amplification technology, information of a detection magnetic field is obtained through a high signal-to-noise ratio photoelectric detection magnetic resonance spectrum, and the sensitivity of the magnetic field is evaluated. Magnetic resonance signals are detected in an all-electricity mode, a complex optical system of traditional fluorescence detection is simplified, and the device has the advantages of being compact in structure, easy to integrate, high in measurement sensitivity and the like.

The invention relates to the technical field of photoelectric detection, and particularly discloses a three-dimensional defect detection method and system based on compound color stripe projection, and the method comprises an upper computer control and processing module which is used for generating a compound color stripe pattern coded with phase difference information, and coordinating and controlling the synchronous operation of the whole system; the structured light projection module is used for receiving the composite color stripe pattern and projecting the composite color stripe pattern to the surface of a measured object at one time; the imaging module is used for receiving the composite colored light reflected after being modulated by the surface of the measured object and separating the composite colored light into monochromatic light signals with different colors for synchronous acquisition; the imaging module further comprises an active highlight suppression unit which is used for dynamically adjusting the polarization direction according to an instruction of the upper computer control and processing module so as to suppress highlight caused by specular reflection. Multiple groups of sine fringes with fixed phase differences are projected to the surface of a measured object at one time. And a plurality of deformed fringe patterns with phase displacement can be synchronously acquired under single exposure.

The invention belongs to the technical field of photoelectric detection, and relates to a gallium oxide nanowire array type solar blind photoelectric detector and a preparation method thereof. Spreading liquid metal gallium on the surface of the substrate to form a liquid metal gallium layer on the surface of the substrate; performing vacuum evaporation on the surface of the liquid metal gallium layer to form a gold film layer to obtain a device precursor; and heating the device precursor to 400-1000 DEG C at a heating rate of 10-15 DEG C / min, and carrying out heat treatment for 1-2h to obtain the sandwich structure device. According to the method, the preparation mode of the array type gallium oxide nanowire is simplified, gallium metal left in the growth process is used as the electrode, the tedious and complex technological process needed in the previous device preparation process is improved, the ordered and regular gallium oxide nanowire array structure is prepared, and the photoelectric detection effect is improved.

The embodiment of the invention provides a photoelectric detection device and an optical detection device. The photoelectric detection device comprises a light beam separation assembly and a sensor assembly. The light beam separation assembly is used for dividing a continuous first light signal into a plurality of beams of second light signals at different spatial positions. The sensor assembly is used for receiving multiple beams of second optical signals. The sensor assembly includes a plurality of sensors, the plurality of sensors including single-pixel sensors. The continuous first optical signal is divided into a plurality of small discrete second optical signals through the light beam separation assembly, so that the light sensing area of each sensor corresponding to a sample is further reduced, the haze noise on a single sensor is further reduced through the small light sensing area, and the haze noise on the single sensor is further reduced under the condition that the original first optical signal is not changed. Noise on a single sensor is reduced, and the signal-to-noise ratio of the photoelectric detection device is improved.

The invention relates to a zero calibration weak measurement high-sensitivity interval compensation method and system, and the method comprises the steps: collecting the light intensity data of two paths and four channels in a zero input state, solving the asymmetry caused by the loss difference of the channels through a weak measurement method, and carrying out the calculation of the asymmetry. And correcting the post-selection state and the compensation sensitivity of the system according to the intensity difference of the output projection to the horizontal polarization state and the vertical polarization state, calculating the phase offset of a high-sensitivity interval according to the loss difference of the four channels, generating a compensation phase, and modulating the center of the high-sensitivity interval to a working point. Compared with the prior art, high-sensitivity loss and high-sensitivity interval offset caused by system asymmetry can be corrected through phase compensation and post-selection state correction, it is ensured that a measurement system always works in an optimal sensitivity interval, the measurement sensitivity and stability of a photoelectric detection system under weak measurement are improved, and the measurement accuracy is improved. The method is suitable for application scenes with strict requirements on tiny signal detection.

The invention discloses a vortex beam orbital angular momentum detector based on surface plasmon and a detection method, and belongs to the field of micro-nano photonics and photoelectric detection. The detector is based on a plane photoelectric detector of a metal-semiconductor-metal type, a vortex light field beam splitting structure is arranged on a metal electrode on one side of the detector or between two metal electrodes, the vortex light field beam splitting structure comprises an incident coupling grating, an incident light field carrying different orbital angular momentums can be split into plasmons in different directions, and the plasmons in different directions can be split into a vortex light field. The single detector resolution of the orbital angular momentum of the vortex beam is realized through the direction and propagation loss difference of plasmons. The detector is compatible with an existing semiconductor technology, the structure is simple, vortex light beams carrying high-order orbital angular momentum can be detected, and the rotation direction of a vortex light field can be detected.

The invention discloses a quantum partial discharge detection system and method based on single photon measurement. The system comprises a photoelectric detection module and an information transmission and processing module which are connected in pairs. A free space light collection unit in the photoelectric detection module is used for converging photons of partial discharge radiation and guiding the collected photons to a classic weak light detection unit and a single photon detection unit respectively; the classic weak light detection unit is used for converting an optical signal into an electric pulse signal based on an internal photoelectric effect; the single-photon detection unit is used for detecting extremely weak light and even single-photon events and outputting discrete electric pulse signals. The classical weak light detection unit and the single photon detection unit operate in parallel, partial discharge optical detection with a wide dynamic range and a high signal-to-noise ratio is realized through a signal fusion and processing algorithm, electromagnetic interference is effectively inhibited, and a more comprehensive and reliable monitoring means is provided for evaluation of the insulation state of power equipment.

A photodetection sensor having a plurality of performance characteristics. The photodetection sensor includes a semiconductor photodiode chip having a detection area, and includes a photodetector array located within detection area. Photodetector array includes a first photodetector having a first performance, and includes a second photodetector having a second performance characteristic different from first performance characteristic. First photodetector configured to generate a first detection signal based on light transmitted toward target objects and reflected from first object of target objects to first photodetector, the first detection signal indicative of a time-of-flight of light transmitted toward target objects and reflected from first object to first photodetector. Second photodetector configured to generate a second detection signal based on light transmitted toward target objects and reflected from second object of target objects to second photodetector, the second detection signal indicative of presence of at least one of target objects undetectable from first detection signal.

In one example, an imaging device includes a light-receiving pixel, a first coupling terminal, a first voltage generation circuit, a drive circuit, a reference signal generation circuit, a noise correction circuit, a comparison circuit, and a processing circuit. The light-receiving pixel generates a pixel signal. The drive circuit is configured to drive the light-receiving pixel on the basis of a voltage from the first voltage generation circuit at the first coupling terminal. The reference signal generation circuit generates a reference signal having a ramp waveform. The noise correction circuit generates a noise correction signal corresponding to the voltage at the first coupling terminal, and superimposes the noise correction signal on the reference signal. The comparison circuit compares the pixel signal and the reference signal with the superimposed noise correction signal. The processing circuit calculates a pixel value based on a result of the comparison.

The invention relates to a dynamic measurement device for a deflection angle of a transmission shaft system based on a laser alignment and error separation technology. The dynamic measurement device mainly comprises a laser alignment module, an axis measurement module, a photoelectric detection module, a laser compensation module, a multi-channel signal acquisition card and a computer. The laser collimation module emits a collimated laser beam as a linear measurement reference, and the multiple axis measurement modules synchronously measure the dynamic axis tracks of the two transmission shafts in the rotation process. The photoelectric detection module is used for sequentially adjusting the poses of the measuring heads on all the axis measuring modules to be consistent, and the laser compensation module is used for compensating laser beam drift in real time so as to improve the laser alignment precision. And finally, fitting and calculating the dynamic deflection angle between the two sections of transmission shafts according to the axis trajectories of the plurality of sections. The three-point method error separation technology is adopted to separate the motion error and the section roundness error of the shaft, the dynamic measurement precision of the axis track is improved, and dynamic measurement of the deflection angle between any two sections of transmission shafts in a high-speed transmission system is achieved.

The invention discloses a system and a method for realizing positive and negative weighting in an optical domain, and the system comprises a multi-wavelength light source array which provides multi-channel optical signals, and each wavelength corresponds to an input channel; the adjustable bias photoelectric modulator arrays are in one-to-one correspondence with the light sources, a quiescent working point is biased in a positive / negative slope linear region of a transmission curve through an independent bias circuit, positive and negative weight symbol control is realized, and an input electric signal is loaded; the multi-wavelength micro-ring weighting unit is used for weighting the modulated optical signal by regulating and controlling the transmissivity of the micro-ring; the photoelectric detection unit adopts a single-path detector to receive a composite optical signal and convert the composite optical signal into an electric signal; and the capacitor blocking and signal synthesis unit filters a direct current component, synthesizes an alternating current weighted signal and outputs a real number weighted sum. The system does not need to balance detectors and redundant devices, simplifies hardware architecture, reduces cost and size, reduces power consumption, improves weighting precision and reliability, supports flexible expansion of multi-wavelength channels, adapts to requirements of a large-scale optical neural network, and provides support for optical calculation integration and low-power-consumption landing.

The invention relates to the technical field of photoelectric detection, in particular to a global self-defined sampling method based on a germanium-silicon photoelectric detector array, which comprises the following steps of: S1, constructing the germanium-silicon photoelectric detector array with an n * t specification, receiving a target optical signal by using each detector unit as a pixel point, converting the target optical signal into an initial current signal, the signal is linearly amplified into a voltage signal through an external transimpedance amplifier; s2, digitalizing the voltage signal into a binary discrete digital signal through a high-speed analog-to-digital converter at the output end of the trans-impedance amplifier; and S3, performing global synchronous sampling to obtain a first group of data, performing repeated sampling in the same mode to obtain multiple groups of data, performing pixel-by-pixel superposition to generate fused data, and performing user-defined setting on the repeated sampling frequency within 1-1024 times. By customizing the number of repeated sampling times and data superposition, adapting to different light intensities and expanding the detection dynamic range, the problems of strong light overexposure and weak light underexposure are solved, the data consistency is guaranteed in combination with global synchronous sampling, and the detection precision and the environmental adaptability are improved.

The invention relates to an ultraviolet photoelectric detector, a preparation method and application in a programmable logic gate. The apparatus includes: a support base; the ultraviolet band optical response unit comprises an optical substrate and an inorganic quantum dot photosensitive layer, and at least a PN junction is formed between the inorganic quantum dot photosensitive layer and the optical substrate; the charge transmission layer is located on the inorganic quantum dot photosensitive layer and at least forms atomic-scale heterogeneous contact with the inorganic quantum dot photosensitive layer, during photoelectric detection, target ultraviolet light irradiates on the charge transmission layer, and the charge transmission layer is electrically connected with the inorganic quantum dot photosensitive layer based on the detection light intensity state of the target ultraviolet light. The photo-generated current polarity of the ultraviolet photoelectric detector under the target ultraviolet light is regulated and controlled; the detection light intensity state at least comprises a comparison state between the light intensity of the target ultraviolet light and the detection critical light intensity. According to the invention, bipolar ultraviolet photoelectric detection under single-wavelength power modulation can be realized, and the reconfigurable polymorphic logic gate application can be effectively realized.

The invention provides an infrared target simulator focusing collimation projection optical system and a design method thereof. The optical system is composed of a telescope objective, an intermediate field lens and a relay lens group. A source target and a background image generated by the infrared target simulator are input into the DMD and then are incident to the focusing collimation projection optical system through the DMD, the incident light firstly passes through the relay lens group and the intermediate field lens to generate a primary image of the image on the DMD, and then the primary image surface is collimated and projected to an entrance pupil of a tested photoelectric device through the telescope objective. According to the invention, optical material parameters are finely analyzed and matched, three infrared optical materials are adopted to form a lens group, a field lens is added to compress the aperture of a light beam, and only five lenses are used, so that achromatism and athermalization are realized while high transmittance is ensured. And a focusing lens group and a precise mechanical structure are arranged in the relay lens group, so that the target simulation requirement of photoelectric detection equipment such as a guide head at a wider working temperature range is met, and meanwhile, the requirement of obtaining a clear simulation target scene by matching detected photoelectric equipment with different working distances can be met.

The invention provides a wide-field imaging and confocal integrated system and method for a solid-state spin color center. The system comprises an exciting light module, a wide-field branch, a confocal branch, a first guide element, a first double-color piece, an objective lens, a probe comprising a solid-state spinning color center, a first filter, a second guide element, a photoelectric detection light path, a wide-field imaging light path and a microwave module. The exciting light module outputs two paths of exciting light in a switchable mode, the two paths of exciting light are transmitted to the confocal branch and the wide-field branch respectively so as to obtain light beams meeting confocal and wide-field imaging respectively, and the two paths of light beams are guided to the same laser excitation and fluorescence detection light path through the first guiding element and then are transmitted to the wide-field branch through the second guiding element. And then the collected fluorescence is guided to a photoelectric detection light path or a wide-field imaging light path by a second guide element, so that switching of two detection modes can be realized, integration of wide-field imaging and confocal can be realized, compared with respective reconstruction in the prior art, the method is more convenient, repeated debugging in the switching process is avoided, and real-time switching can be realized.

Improved image quality in photodetection devices that count pulses with a counter is disclosed. In one example, a first sensor unit generates a first pulse signal in response to incidence of photons. A second sensor unit generates a second pulse signal in response to incidence of photons. A first counter counts a count value in synchronization with one of a plurality of signals including the first and second pulse signals, and outputs a first digital signal indicating the count value and a first carry flag indicating whether or not overflow has occurred. A second counter counts a count value in synchronization with one of the first carry flag and the second pulse signal, and outputs a second digital signal indicating the count value.

The invention discloses a multi-target sensing and tracking method for detecting an unmanned aerial vehicle swarm through a single-photon laser radar, and belongs to the field of photoelectric detection and signal processing. The problem that a traditional image reconstruction algorithm and a tracking algorithm are difficult to adapt to ultra-low signal-to-noise ratio, high dynamic and multi-target complex sensing requirements is solved. The method comprises the following steps: carrying out systematic prepeak noise self-adaptive suppression on global photon arrival time data acquired by a single-photon laser radar; performing photon event physical statistical modeling and background noise suppression based on the suppressed data to obtain an enhanced residual signal; performing space-time consistency enhancement processing on the enhanced residual signal to realize extraction and reconstruction of a multi-target area; based on the extracted photon events in the multi-target area, performing trajectory fitting and prediction by adopting a Bayesian weighted RANSAC (Random Sample Consensus) fitting method; and designing a target tracking algorithm based on scale adaptive updating and template matching of an optical flow method and pyramid search assistance, and carrying out robust tracking on multiple targets. The method is used in target tracking field.

The invention discloses a radar photoelectric cooperative detection method and system based on radio orientation and optical measurement, and belongs to the field of radio fixed.The method comprises the steps that a radio signal of a target is obtained, parameter estimation is conducted on the radio signal, and direction-of-arrival data and statistical characteristic parameters of the target are obtained; generating a guide instruction according to the direction of arrival data to drive a photoelectric detection device to point to the airspace where the target is located, and obtaining real-time optical image data of the airspace where the target is located through the photoelectric detection device; projecting the error uncertainty range to a two-dimensional plane of the real-time optical image data, and generating an adaptive probability search area; performing visual feature extraction on the real-time optical image data in the adaptive probability search area, and detecting to obtain at least one candidate visual target; and calculating the association confidence of each candidate visual target and the direction of arrival data, and judging a final detection target. According to the invention, closed-loop self-calibration of the whole radar photoelectric system is realized.

Provided is an EVS to which an image plane phase difference method AF function can be easily applied.A photodetection device includes: a first pixel configured to photoelectrically convert incident light from a portion on one side to generate a first current; a second pixel configured to photoelectrically convert the incident light from a portion on a side opposite to the portion of the first pixel to generate a second current; a first luminance circuit provided individually corresponding to the first pixel and configured to generate a first luminance signal according to the first current; a second luminance circuit provided individually corresponding to the second pixel and configured to generate a second luminance signal according to the second current; a first current comparison circuit provided individually corresponding to the first pixel, and configured to compare the first luminance signal with a reference signal and convert the first luminance signal into a first digital signal; a second current comparison circuit provided individually corresponding to the second pixel, and configured to compare the second luminance signal with the reference signal and convert the second luminance signal into a second digital signal; and a control unit configured to adjust a focal position of the incident light on the basis of the first digital signal and the second digital signal.

The invention discloses a MoTe2 / Bi < 0.5 > Sb < 1.5 > Te3 heterojunction thin film and application thereof in broadband near-infrared photoelectric detection. The heterojunction thin film is formed by stacking a MoTe2 thin film prepared by magnetron sputtering and a Bi < 0.5 > Sb < 1.5 > Te3 thin film prepared by magnetron sputtering, and the MoTe2 thin film and the Bi < 0.5 > Sb < 1.5 > Te3 thin film are in direct contact to form a heterojunction interface; the preparation method comprises the following steps: putting a cleaned n-Si substrate into a magnetron sputtering instrument, sputtering a MoTe2 film in an inert atmosphere, and carrying out annealing treatment to obtain n-Si / MoTe2; and continuously putting the n-Si / MoTe2 into the magnetron sputtering instrument, sputtering a Bi0. 5Sb1. 5Te3 film on the surface of the MoTe2 film in an inert atmosphere, and carrying out annealing treatment. According to the invention, a self-powered practical device with high responsivity, high specific detection rate, fast response speed and high stability can be obtained.

The invention relates to the technical field of optical signal transmission, in particular to an optical fiber polarization measurement system and method. The optical fiber polarization measurement system comprises a light source which is located at the light incident side of a to-be-measured optical fiber and is used for inputting detection laser to the to-be-measured optical fiber; the optical fiber temperature control assembly is circumferentially arranged along the periphery of the to-be-measured optical fiber and is used for adjusting the temperature of the to-be-measured optical fiber; the light-emitting optical fiber is the same as the optical fiber to be detected in model and is welded with the output end of the optical fiber to be detected through polarization-maintaining welding; the heat preservation rotating assembly is arranged close to the output end of the light-emitting optical fiber and used for providing a constant-temperature environment for the light-emitting optical fiber and driving the light-emitting optical fiber to rotate concentrically. The polarization analyzing assembly is located at the output end of the light-emitting optical fiber and used for screening the output laser output by the light-emitting optical fiber based on the polarization direction; the photoelectric detection assembly is located on the side, away from the light outlet optical fiber, of the polarization detection assembly and used for detecting the optical power of the polarized laser screened by the polarization detection assembly. The measuring efficiency can be effectively improved, the cost is reduced, and the structure is simplified.