4665 results about "Photodetector" patented technology

The invention relates to the technical field of laser control, and provides a high-dynamic-range multi-channel laser interference control method and related equipment. Channel signals of a plurality of target channels are obtained in real time according to a plurality of preset photoelectric detectors, time domain-frequency domain-space three-dimensional sampling is performed on the channel signals to construct an original tensor, joint optimization processing is performed on the original tensor to obtain a noise reduction tensor, phase unwrapping is performed on the noise reduction tensor to obtain an absolute phase matrix, and the absolute phase matrix is subjected to noise reduction processing to obtain an absolute phase matrix. Performing dynamic range expansion on the absolute phase matrix to obtain an enhanced phase matrix, performing multi-wavelength calculation and environment compensation on the enhanced phase matrix to obtain a distance matrix, and performing vibration compensation on the distance matrix to obtain a piezoelectric driving signal. According to the channel laser interference control method, through a series of advanced algorithms and processing means such as multi-dimensional signal acquisition, combined noise reduction optimization, precise phase unwrapping, dynamic range expansion and vibration compensation, comprehensive improvement of laser interference measurement signals is realized.

A LiDAR apparatus, including: a laser to generate an optical signal; modulation components configured to receive the optical signal as an input and to output at least two corresponding modulated optical signals at respective output ports, wherein each modulated optical signal is modulated by a corresponding pseudo-random bit sequence, and: (i) the optical signals have respective different delays such that the modulations do not overlap in time; or (ii) the pseudo-random bit sequences have low cross-correlation; for each of the at least two modulated optical signals, a corresponding optical transmitter configured to transmit the corresponding modulated optical signal towards a corresponding surface spaced from the LiDAR apparatus by a corresponding distance, and a corresponding optical receiver configured to receive a portion of the transmitted optical signal scattered and / or reflected by the surface, the received portion of the optical signal having a phase shift and / or Doppler shifted angular frequency due to radial motion of the LiDAR apparatus relative to the surface; at least one photodetector to receive the optical signals received by the optical receivers, interfered with a reference beam, and to generate a corresponding output signal; at least one analogue to digital converter to generate a digital signal representing the output signal from the at least one photodetector; and a digital signal processing component configured to process the digital signal to generate LiDAR data representing the distances to the surfaces and / or relative velocities of the surface(s) with respect to the apparatus.

A machine vision system may include a meta-imager including a meta-optic and a polarization-sensitive photodetector. A machine vision system may further include and at least one processor operably coupled to the polarization-sensitive photodetector, and at least one memory operably coupled to the at least one processor. A machine vision system may be configured to: receive, from the polarization-sensitive photodetector, a plurality of feature maps; input, into a trained artificial neural network, the plurality of feature maps; and process, using the trained artificial neural network, the plurality of feature maps to recognize an object.

The present disclosure pertains to head-mounted dual-sided photoplethysmography (PPG) systems and methods for blood flow measurement. In one embodiment, a system comprises a frame designed to be worn on a user's head, integrating a first PPG device positioned on the first side of the user's nose and a second PPG device on the opposite side. Each PPG device includes a light source and photodetector, enabling the capture of optical signals indicative of blood flow within the nasal tissue. A computer is operatively connected to both PPG devices, responsible for obtaining first and second signals from each side and processing these signals to calculate comprehensive measurements of the user's blood flow. This dual-sided configuration enhances measurement accuracy and reliability by mitigating motion artifacts and improving signal quality compared to traditional single-sided PPG systems.

The invention belongs to the technical field of retina imaging and fundus three-dimensional reconstruction, and particularly relates to a color three-dimensional fundus imager optical system. Comprising a large eye objective lens, a dichroscope, a hollow reflector, a focusing lens, a spectroscope, a retina lens, a retina imaging chip, a fixation lens, a sighting mark lamp, an illumination lens, an annular light source, a pupil lens, a pupil imaging chip, an infrared lens, an infrared dodging lens, an infrared light source, a scanning lens, a three-dimensional galvanometer, a collimator, a coupler, a frequency sweeping light source and a dispersion compensator. A polarization controller, a coupler and a photoelectric detector. The system is mainly composed of a visible light imaging light path, an infrared imaging light path and a laser imaging light path, the visible light imaging light path is used for shooting color fundus two-dimensional images, the infrared imaging light path is used for real-time positioning and focusing of human eye pupils, and the laser imaging light path is used for three-dimensional tomography of retinas. The objective of the invention is to solve the problem that existing medical equipment cannot acquire fundus color three-dimensional images.

A positron emission tomography (PET) scanner includes a plurality of gamma radiation detector modules arranged to form a detector ring. Each detector module includes an array of scintillator detectors. Each scintillator detector comprises a monolithic scintillation crystal and a plurality of photodetector arrays, such as silicon photomultipliers (SiPMs). A photodetector array is positioned on at least two nonparallel faces of each scintillation crystal. In some examples, a photodetector array is positioned on each of three orthogonal faces of each scintillation crystal.

The present disclosure relates to an active graded magnetic compensation system and method for an unshielded SERF magnetometer. The system comprises: a detection laser, a half-wave plate, a magnetic field compensation coil, a magnetic field modulation coil, a non-magnetic heating assembly, an alkali-metal atomic vapor cell, a polarizing beam splitter prism, a balanced photodetector, a graded feedback control module, a pump laser, a quarter-wave plate, a focusing lens and a photodetector. By means of the present disclosure, a graded compensation system is used to realize high-precision compensation for a magnetic field within a large dynamic range in a geomagnetic environment, thereby ensuring that an instrument carries out high-sensitivity magnetic field measurement under geomagnetic conditions.

An on-chip mid-infrared micro-ring resonant cavity microfluidic spectrometer is integrated on a substrate material and comprises a spot size converter, an optical coupler, a microfluidic module, a micro-ring resonant cavity, a miniature thin-film resistance heater, a sequential control power supply module, an optical filtering system and a photoelectric detector array. Selective filtering is performed on an input optical signal, and the flow and flow velocity of liquid or gas to be detected are controlled by using the microfluidic module, so that selective absorption of spectral components of the liquid or gas to be detected is realized. In addition, the invention also discloses a mid-infrared integrated optical chip micro-fluidic multiphase detection device comprising the spectrometer and a detection method thereof, the device also comprises a pumping and reference light source module and an on-chip mid-infrared frequency comb generation module, a broadband frequency comb is generated as a light source, a photoelectric detector array is used for collecting signals, and the detection precision is improved. The detection and inversion of the type and concentration of multi-component liquid or gas to be detected are realized, and the on-chip, real-time and micro detection of multi-component substances is realized.

The invention relates to an optical acoustic sensor, in particular to a high-sensitivity acoustic sensor based on Fano resonance and a measuring method. The problem that an existing optical acoustic sensor is low in sensitivity is solved. A high-sensitivity acoustic sensor based on Fano resonance comprises a 1550nm laser, a phase modulator, a first polarization controller, a conical optical fiber, a CaF2 crystal resonant cavity, a second polarization controller, a photoelectric detector, an oscilloscope and a computer. The emergent end of the 1550nm laser is connected with the head end of the conical optical fiber through the phase modulator and the first polarization controller in sequence; the conical optical fiber is coupled with the CaF2 crystal resonant cavity; the tail end of the conical optical fiber is connected with the incident end of the photoelectric detector through the second polarization controller; the signal output end of the photoelectric detector is connected with the signal input end of the oscilloscope; the signal output end of the oscilloscope is connected with the signal input end of the computer. The method is suitable for acoustic signal measurement in the fields of industry, traffic, environmental protection, medical treatment and the like.

Data are optically transmitted from a power tool device, such as a power tool, a power tool battery charger, power tool pack adapter, and / or a battery pack. The data are stored in a memory of the power tool device and are encoded as optical signal data to provide an encoded representation of the stored data. An optical transmitter (e.g., a light emitting diode or a flat panel display) transmits the optical signal data, which are detected or otherwise received by an optical receiver device, which may include a camera or other photodetector. The optical signal data may include light signals generated by an LED, where the data are encoded using an encoding scheme that modulates one or more characteristics (e.g., amplitude, wavelength, color) of the generated light signals. The optical signal data may also include images (e.g., barcodes, QR codes) or characters.

The invention discloses a method for detecting the strain of a key part of a wind turbine generator based on a temperature compensation OFDR demodulation weak fiber bragg grating array, and relates to the technical field of wind turbine generator detection, and the method comprises the steps: installing a weak fiber bragg grating sensor array at the key strain part according to the structural characteristics of the wind turbine generator, a temperature reference grating is arranged in the non-strain area or the constant-temperature area so as to monitor the temperature change in real time; a tunable laser, an optical fiber coupler and a photoelectric detector are utilized to construct an optical frequency domain reflection demodulation system, and system calibration is completed; based on an optical frequency domain reflection demodulation system, reflection spectrum signals are collected, the relation between wind turbine generator strain and temperature change is analyzed through a temperature compensation mechanism, and strain information of key parts of the wind turbine generator is obtained. According to the method, the accuracy and reliability of strain detection are effectively improved, and the problem of measurement errors caused by neglecting the influence of temperature change in a traditional method is solved.

The invention discloses a double-comb non-cooperative target ranging system based on single photon detection, which is characterized in that an optical pulse output by a first optical frequency comb is divided into two paths of light through a first beam splitter, the first path of light is combined with one of two paths of light divided by a second optical frequency comb through a second beam splitter, and the combined light is transmitted to a first nonlinear frequency up-conversion module; a sum frequency light pulse in the wave band of 780 nm is generated and detected by a base avalanche diode photoelectric detector, and then a time-dependent single photon counter is triggered to start counting; the second path of light is output to a beam expanding collimator through the circulator and irradiates a target to be measured through spatial propagation, the beam expanding collimator collects diffuse reflection light and returns the diffuse reflection light to a third port of the circulator along the original path, and the diffuse reflection light and the other path of light split by the second optical frequency comb through the second beam splitter are combined and transmitted to a second nonlinear frequency up-conversion module; the up-conversion light after sum frequency conversion passes through the optical filter group and then is recorded by a stop end of the single photon counting module, multi-cycle accumulative statistics is carried out by the time correlation single photon counter, and finally a photon counting waveform is reconstructed and the flight time difference of the to-be-measured target is calculated by the computer.

To ensure stable transfer capability. A photodetector includes a semiconductor layer having a first surface and a second surface located on opposite sides, a photoelectric conversion unit in the semiconductor layer that converts, through photoelectric conversion, light incident from a second surface side of the semiconductor layer, a charge holding unit on a first surface side of the semiconductor layer, a transfer transistor that includes a gate electrode and that transfers signal charge generated by the photoelectric conversion unit through the photoelectric conversion to the charge holding unit, and an isolation region on the first surface side of the semiconductor layer. The gate electrode includes a head on the first surface side of the semiconductor layer and legs that extend from the head in a thickness direction of the semiconductor layer and that are in the isolation region adjacent to the semiconductor layer via a gate insulating film.

A circuit, including: a photodetector including a first readout terminal and a second readout terminal different than the first readout terminal; a first readout circuit coupled with the first readout terminal and configured to output a first readout voltage; a second readout circuit coupled with the second readout terminal and configured to output a second readout voltage; and a common-mode analog-to-digital converter (ADC) including: a first input terminal coupled with a first voltage source; a second input terminal coupled with a common-mode generator, the common-mode generator configured to receive the first readout voltage and the second readout voltage, and to generate a common-mode voltage between the first and second readout voltages; and a first output terminal configured to output a first output signal corresponding to a magnitude of a current generated by the photodetector.

The invention discloses an independent double-single-side-band direct detection system based on geometric shaping and digital chaotic encryption, and belongs to the field of terahertz communication. According to the detection system, an external cavity laser ECL of a sending end generates continuous optical carriers, the continuous optical carriers are input into an I / Q modulator, a TX-DSP module generates two independent vector radio frequency signals of GS-QPSK and GS-NQAM through geometric shaping and a three-dimensional multi-vortex chaos system technology, the I / Q modulator is driven to modulate the input optical carriers, and the optical carriers are transmitted to a receiver. After being amplified, the terahertz signals are input into a one-way carrier photoelectric detector for frequency beating to obtain independent double-sideband terahertz signals, the independent double-sideband terahertz signals are input into a frequency mixer of a receiving end for frequency mixing with generated local oscillation signals, down-conversion of the signals is achieved, and fundamental frequency signals are obtained; and then the data are input to an RX-DSP module, normalization, down-sampling, signal separation, de-mapping, symbol-level and bit-level decryption and other operations are carried out, and finally two paths of original data are obtained to solve the bit error rate. According to the invention, the system communication capacity is improved, and the security of independent double-sideband signal transmission is improved.

The invention belongs to the technical field of atmospheric environment monitoring, and particularly relates to an unmanned aerial vehicle laser radar calibration quality control system and method, and the system comprises an unmanned aerial vehicle flight platform, a laser radar module, a navigation positioning module, a control communication module, a data processing module and a ground station. The unmanned aerial vehicle flying platform comprises a shockproof holder and a protective pod; the laser radar module comprises a laser radar, a scanner module and a photoelectric detector module. According to the invention, one unmanned aerial vehicle is adopted to carry various different types of laser radars, the extinction coefficient is measured by combining optical beam splitting, signal processing and algorithm inversion technologies, and atmospheric particulate classification is effectively monitored through cooperation of a high-precision optical system and an algorithm; the extinction coefficient and the depolarization ratio work cooperatively, high-precision quantitative analysis and classification of pollutants can be achieved, the combined measurement function of the extinction coefficient and the depolarization ratio is achieved, and high-resolution three-dimensional monitoring of atmospheric particulates is achieved through multi-parameter cooperative inversion of the laser radar.

Aspects of the present disclosure include methods for determining baseline noise of a photodetector (e.g., in a light detection system of a particle analyzer). Methods according to certain embodiments include irradiating a sample having particles in a flow stream, detecting light with the photodetector from the irradiated flow stream, generating data signals from the detected light and calculating a moving average mean squared error of the generated data signals to determine the baseline of the photodetector. Systems (e.g., particle analyzers) having a light source and a light detection system that includes a photodetector for practicing the subject methods are also described. Integrated circuits and non-transitory computer readable storage medium are also provided.

The problem of forming a deep trench isolation structure suitable for photodetectors with small pitch is solved by a process in which a grid of trenches is etched from the front side using high energy plasma followed by annealing. The trenches are filled with an oxide followed by etching to recess the oxide. The trench recesses are filled with semiconductor to form a grid-shaped semiconductor structure. After FEOL processing, BEOL processing, attachment to a second substrate, and thinning from the back side, an etch removes the oxide from the back side. The etch stops on the grid-shaped semiconductor structure. The trenches are then lined and filled from the back side. The front side etch allows the trenches to be made narrow and with highly vertical sidewalls. Lining and filling the trenches from the back side provides good optical and electrical isolation.

A positron emission tomography (PET) scanner includes a plurality of gamma radiation detector modules arranged to form a detector ring. Each detector module includes an array of scintillator detectors. Each scintillator detector comprises a monolithic scintillation crystal and a plurality of photodetector arrays, such as silicon photomultipliers (SiPMs). A photodetector array is positioned on at least two nonparallel faces of each scintillation crystal. In some examples, a photodetector array is positioned on each of three orthogonal faces of each scintillation crystal.

The invention relates to a multi-degree-of-freedom motion synchronous measurement system and method based on time-space domain information fusion, which utilize a heterodyne interference phenomenon generated by a double-frequency light source to realize accurate measurement of displacement and angle by analyzing phase change of an interference signal generated by interaction of a measurement grating and a reference grating. The system comprises a double-frequency light source, an optical element, a measuring grating, a reference grating and a photoelectric detector, and the photoelectric detector comprises an array detector and a common photoelectric detector and is used for receiving interference light signals of different diffraction orders. The processing device at least comprises an angle measuring module. The angle module is used for resolving by fusing phase spatial-temporal characteristics and light spot displacement of signals on the array detector; a displacement module can be further included, calculation is carried out through the phase change of heterodyne interference signals on the detector along with time, and finally synchronous measurement of six-degree-of-freedom motion parameters can be achieved. The system has the advantages of being accurate, compact in size, high in light source efficiency and the like, and is suitable for multiple fields of photoetching machine wafer table positioning, ultra-precision machine tool machining and the like.

A method is disclosed for use in detecting a pulsed optical beam when the pulsed optical beam is transmitted through a scattering medium, wherein the pulsed optical beam comprises a plurality of optical pulses and the method comprises using a plurality of photodetectors of a photodetector array to detect light which is scattered progressively from the same optical pulse as the optical pulse propagates through a plurality of regions of the scattering medium and which is then received progressively on different photodetectors of the photodetector array. The method may be used in particular, though not exclusively, for non-line-of-sight free-space optical communications. An optical receiver for use in detecting the pulsed optical beam and an associated optical system are also disclosed.

The invention discloses an ultra-compact near-infrared circularly polarized photoelectric detector, which comprises an upper metal electrode plating layer, a lower metal electrode plating layer, a semiconductor substrate, a hexagonal close packing array substrate and a chiral super-surface layer, and can realize rapid and high-responsivity near-infrared circular polarization dependent light detection, and light signals can be directly converted into visible electric signals under zero bias voltage; different photoelectric signal conversion effects can be generated from different directions under irradiation of light with different wavelengths, and reference is provided for preparation of a multi-mode near-infrared circularly polarized photoelectric detector. The invention also discloses a preparation method of the ultra-compact near-infrared circularly polarized photoelectric detector, the preparation method is simple and convenient, the cost is relatively low, batch preparation can be realized, and the produced ultra-compact near-infrared circularly polarized photoelectric detector has the characteristics of high light absorbance, quick response and ultrahigh integration level.

A lithium battery detection device based on BB optical pump magnetic imaging comprises a magnetic shielding cylinder and a substrate arranged in the magnetic shielding cylinder, and a laser, an optical lens system, an atomic gas chamber system, an array lens and an array photoelectric detector are sequentially arranged on the working face of the substrate from left to right; the atomic gas chamber system contains alkali metal atoms and buffer gas; a non-magnetic objective table for placing a lithium battery to be tested is arranged above the atomic gas chamber; according to the device, the array lens is adopted to split and focus a single beam of detection laser into small light spots which are respectively irradiated on different photoelectric detectors, and magnetic field information of a plurality of space point locations is detected at one time, so that the consistency and imaging quality of a subsystem are improved, and the system cost is saved.

Various embodiments of the present disclosure are directed towards an image sensor comprising a pixel with a dual-PD layout for enhanced scaling down. The pixel spans a first integrated circuit (IC) die and a second IC die stacked with the first IC die. The pixel comprises a plurality of photodetectors in the first IC die, and further comprises a plurality of pixel transistors split amongst the first IC die and the second IC die. The plurality of photodetectors are grouped into one or more pairs, each having the dual-PD layout. A DTI structure completely and individually surrounds the plurality of photodetectors, and further extends completely through a substrate within which the plurality of photodetectors are arranged. As such, the DTI structure completely separates the plurality of photodetectors from each other.

Wearable devices for measuring health indicators such as bilirubin are provided. The device includes a skin-facing side including a circuit board. The circuit board includes a spectrometer integrated circuit, at least one light emitting diode (LED) configured to direct light at the subject's skin where the LED is operably connected to a power source, at least one photodetector configured to receive light reflected from the subject's skin, and a microcontroller configured to perform spectral subtraction of said reflected light.

The various embodiments described herein include methods, devices, and systems for detecting photons. As described herein, superconducting photodetectors may be coupled with a waveguide such that reflection is reduced / minimized. In one aspect, an optical circuit includes an optical waveguide and a plurality of photodetectors coupled to the optical waveguide, adjacent photodetectors of the plurality of photodetectors being spaced to meet one or more preset destructive interference criteria.

Disclosed herein is a method for determining at least one compensated detector signal for at least one photodetector. The at least one photodetector includes at least one detector element configured for generating at least one detector signal depending on an illumination of the at least one detector element. The method includes the following steps:a) determining at least one dark detector resistance by using the at least one detector element and inhibiting illumination of the at least one detector element;b) generating at least one bright detector signal by using the at least one detector element and allowing illumination of the at least one detector element; anddetermining at least one compensated detector signal for compensating at least one temperature drift of the at least one detector element by using at least one evaluation unit.Also disclosed herein are a method for determining at least one item of measurement information on at least one measurement object by using at least one photodetector, a photodetector and a spectrometer.

An adjustable bandwidth current-to-voltage converter for use in an optical receiver includes an input configured to receive current from a photodetector; an amplifier stage connected to the input; a feedback path connected to the amplifier stage and to an output, wherein the feedback path includes a feedback element and an operating mode switch configured to set one of photodetector amplifier with dynamic load (PADL) mode and an integrate-and-dump (I&D) mode. The PADL mode is for higher baud operation than the I&D mode.

The present invention relates to an SPAD-type photodetector, the SPAD-type photodetector comprising: an SPAD-type photodiode comprising, in a semiconductor substrate: a first doped region of a first conductivity type and a second doped region of a second conductivity type opposite to the first conductivity type to form a PN junction; and a quenching transistor including a channel of the second conductivity type in the substrate, a gate electrically isolated from the substrate by a dielectric layer, and a third doped region of the first conductivity type flush with an upper surface of the substrate. A dielectric layer is interposed between the gate and the first doped region, and a channel is defined by the first doped region and the third doped region.

The invention provides a signal acquisition system of a photoelectric detector. In the signal acquisition system, a transimpedance pre-amplification circuit is arranged at the output end of the photoelectric detector, and a passive high-pass filter circuit is connected between the transimpedance pre-amplification circuit and a post-voltage amplification circuit. And a feedback network is formed in the transimpedance pre-amplification circuit and is used for converting a current signal output by the photoelectric detector into a proportional first voltage signal and outputting the proportional first voltage signal. The filter circuit is a third-order LC high-pass filter circuit and is used for suppressing direct current, low frequency and self-beat frequency components and keeping a 10-90MHz pass band flat. The rear voltage amplification circuit adopts a voltage amplification structure of a voltage operational amplifier, the voltage gain Av is 6-10, and the super-band gain is limited through a shunt capacitor. According to the embodiment of the invention, through the structure and parameter setting, the noise gain peak value is suppressed, and the system stability is improved.