342 results about "Avalanche photodiode" patented technology

The invention provides a bias voltage providing circuit of an avalanche photodiode and a PON gateway, and relates to the technical field of optical communication. The bias voltage providing circuit of the avalanche photodiode comprises a bias voltage input unit, a bias voltage control input processing unit and an avalanche photodiode protection unit. When the illumination intensity of the target avalanche photodiode exceeds the preset illumination intensity, the photo-generated current of the target avalanche photodiode exceeds the preset current, and the avalanche photodiode protection unit responds to the situation that the photo-generated current of the target avalanche photodiode exceeds the preset current. The diode bias voltage applied to the target avalanche photodiode is reduced, so that the photo-generated current of the target avalanche photodiode is reduced, and overload protection of the target avalanche photodiode is completed. Based on the above content, the problem that the target avalanche photodiode is easy to damage due to overload in the prior art can be improved.

A photoelectric conversion apparatus includes a plurality of avalanche photodiodes. Each of the plurality of avalanche photodiodes includes an avalanche multiplication unit formed by a first semiconductor region of a first conductivity type that is arranged at a first depth, and a second semiconductor region of a second conductivity type different from the first conductivity type and which is arranged at a second depth deeper than the first depth. A fourth semiconductor region at least one of a conductivity type and an impurity concentration of which is different from those of a third semiconductor region of the second conductivity type is arranged at a position shallower than the third semiconductor region, and a depth of a boundary portion between the third semiconductor region and the fourth semiconductor region is deeper than that of the avalanche multiplication unit.

The invention is suitable for the technical field of distance measurement, and provides a distance detection method and device for an underwater target, electronic equipment and a program product. The method is applied to a frequency-modulated continuous wave laser detection system, and a signal receiving end of the frequency-modulated continuous wave laser detection system comprises a two-dimensional matrix detector array composed of a plurality of single-photon avalanche photodiodes. The method comprises the following steps: transmitting a plurality of first laser signals with different frequencies to an underwater target through a signal transmitting end of a frequency-modulated continuous wave laser detection system; receiving second laser signals with different frequencies through a plurality of single-photon avalanche photodiodes; performing two-dimensional discrete synthesis processing on the second laser signals with different frequencies to obtain target echo signals; and determining the distance between the underwater target and the frequency-modulated continuous wave laser detection system according to the target echo signal. According to the frequency-modulated continuous wave laser detection system, a plurality of laser signals with different frequencies can be transmitted and received, so that the detection distance and the resolution ratio of an underwater target can be improved.

A visualization system for dynamically visualizing an eye includes a laser module operable for outputting a primary laser beam along a beam axis, a beam splitter positioned in the beam axis and configured to direct a first beam portion along the beam axis and a second beam portion along a detection axis that is orthogonal to the beam axis. A microelectromechanical system (MEMS) scanner is arranged on the beam axis and configured, in response to the first beam portion, to output a scanning laser along a visualization path. An avalanche photodiode (APD) detector receives the second beam portion. A 4F correlator optical system has a spatial filter arranged along the visualization path. An optional optical flat may be disposed between the eye and the 4F correlator optical system to achieve stereo parallax.

According to one embodiment of the present disclosure, a multipath interference correction system for a coaxial scanning LIDAR, includes a scanner driving unit configured to drive a scanner included in a coaxial scanning LIDAR and obtain a position signal of the scanner, a measurement light modulation signal input unit configured to obtain a demodulation signal of measurement light emitted from laser of the coaxial scanning LIDAR, a detection light input unit configured to receive detection light mixed with reflection light and multiple interference light from an avalanche photodiode of the coaxial scanning LIDAR and output a detection light signal, and a real-time processor for outputting a depth map based on the detection light signal, the demodulation signal of the measurement light, and the position signal of the scanner.

The invention provides a single-photon detector gating signal generation system and generation method. The system comprises a bias voltage source; the gating circuit is provided with a first sine branch and a second sine branch, the first sine branch is configured to output a first sine voltage signal, and the second sine branch is configured to output a second sine voltage signal; the frequency of the first sinusoidal voltage signal is greater than that of the second sinusoidal voltage signal; the second sinusoidal voltage signal, the first sinusoidal voltage signal and the bias voltage signal are matched to generate a gating signal acting on the avalanche photodiode; based on the period of the first sinusoidal voltage signal, the gating signal has an amplitude greater than a preset value in a continuous first number of periods, and the gating signal does not have an amplitude greater than the preset value in a subsequent continuous second number of periods. The generated gating signal can accelerate the carrier removal process from the physical mechanism level, the post-pulse probability is suppressed, the required dead time is effectively shortened, and the data rate of the detector is further improved.

The invention provides a detection system and method for an avalanche photodiode, and the system comprises an arbitrary signal generator, a laser, an adjustable attenuator, a time-to-digital converter and a test processor, the first output end of the arbitrary signal generator is connected with the laser, the laser is connected with the adjustable attenuator, and outputs a light pulse to the adjustable attenuator; the adjustable attenuator inputs the attenuated optical signal to the input end of the avalanche photodiode to be tested; a second output end of the arbitrary signal generator is connected with a time-to-digital converter; the time-to-digital converter receives an output signal of the avalanche photodiode to be tested; the test processor is connected with a to-be-tested avalanche photodiode and is used for debugging and configuring parameters of the to-be-tested avalanche photodiode; a to-be-detected avalanche photodiode is placed on the detection tool, and the detection tool and the semiconductor refrigerator are packaged together. According to the invention, the compatibility and integration degree of the system can be improved, the stability of the system is improved, and the sensitivity to detected photons is high.

A photoelectric conversion apparatus including a first substrate including a first semiconductor layer and a first wiring structure stacked on the first semiconductor layer, and a second substrate including a second semiconductor layer and a second wiring structure stacked on the second semiconductor layer, includes an avalanche photodiode arranged on the first semiconductor layer, a first resistive element arranged on the first substrate and connected to the avalanche photodiode, a waveform shaping portion arranged on the second semiconductor layer and configured to shape an output signal of the avalanche photodiode, and a second resistive element arranged on the first substrate and connected to the avalanche photodiode, the waveform shaping portion, and the first resistive element.

The invention provides an FSO multi-sensor fusion method based on unscented Kalman filtering and an RBF neural network, and the method comprises the steps: carrying out the unscented Kalman filtering time updating, and carrying out the measurement of a noise covariance adjustment mechanism and an event triggering mechanism based on light intensity self-adaption; the unscented Kalman filter measures and adjusts confidence weights of the infrared camera and the four-quadrant detector according to the channel state provided by the avalanche photodiode, and processes data output by the infrared camera and the four-quadrant detector according to the confidence weights; then, the posterior state estimation of the unscented Kalman filter at the current moment is output, and a position component is extracted and transmitted. Normalized light intensity reflecting channel quality is used as a key state to carry out synchronous estimation, an RBF neural network is used to carry out dynamic modeling and compensation on nonlinear errors of a four-quadrant detector, and a self-adaptive unscented Kalman filtering framework with a line learning capability is constructed. And finally, a virtual sensor output with high update rate, high precision and high sensitivity is generated.

The photoelectric conversion device includes a semiconductor layer provided with an avalanche photodiode, and an interconnection structure layer provided on a side of a first surface of the semiconductor layer. The interconnection structure layer includes an interconnection structure made of a metal material and overlapping with the avalanche multiplication region of the avalanche photodiode in a plan view. The interconnection structure includes a first interconnection, a second interconnection disposed farther from the first surface than the first interconnection, and a contact electrode electrically connecting the first interconnection and the second interconnection. An opening is provided in the first interconnection in a portion overlapping with the avalanche multiplication region in the plan view. The second interconnection is disposed so as to overlap an entire of the opening in the plan view. The contact electrode is arranged around the opening in the plan view.

A radiation detector includes: a scintillator including a pair of end surfaces opposing each other in a first direction and one side surface coupling the end surfaces; a semiconductor photodetector including a semiconductor substrate; and a wiring member electrically connected to the semiconductor photodetector. A length of the scintillator in the first direction is longer than that of the scintillator in a second direction orthogonal to the one side surface. A length of the one side surface in the first direction is longer than a width of the one side surface in a third direction. The semiconductor substrate includes a plurality of photodetection regions disposed in a first portion and first electrodes and a second electrode disposed in a second portion. Each of the photodetection regions includes a plurality of avalanche photodiodes arranged to operate in Geiger mode and a plurality of quenching resistors.

A semiconductor element including an array in which a plurality of avalanche photodiodes is arranged includes a plurality of first electrodes configured to receive supply of a first voltage to be used by the plurality of avalanche photodiodes from outside, and at least one second electrode configured to receive supply of a second voltage from outside different from the first voltage. The plurality of first electrodes and the at least one second electrode are disposed outside the array. The at least one second electrode is disposed between one and another one of the plurality of first electrodes.

The present disclosure aims to provide a photoelectric conversion device capable of suppressing an increase in power consumption of a SPAD pixel. For example, a photoelectric conversion device may include an avalanche photodiode including an anode and a cathode in each pixel of a pixel array. The device may include a recharger configured to recharge the anode or the cathode once per unit exposure time, a gating circuit configured to generate a pulse signal based on an output of the avalanche photodiode at a plurality of different timings within the unit exposure time, and a counter configured to count the pulse signal from the gating circuit.

The present disclosure relates to a light reception element with which it is possible to perform inspection in a shorter time. Provided is a light reception element comprising a pixel array unit in which pixels are arranged in an array form, each of the pixels comprising an avalanche photodiode element, a waveform shaping circuit that shapes the output of the avalanche photodiode element into a pulse, and a counter circuit that counts a detection pulse outputted by the waveform shaping circuit or an inspection pulse outputted by an inspection pulse generation circuit, wherein the pixel has a determination circuit that determines whether the counter circuit is normal or not on the basis of a count value outputted from the counter circuit. The present disclosure can be applied, for example, to a light reception element in which a counter circuit for counting the number of photons is provided for each pixel.

Photoelectric conversion devices and apparatuses are disclosed. An apparatus in which a photoelectric conversion unit is disposed on a semiconductor substrate including a first surface and a second surface on an opposite side of the first surface. The photoelectric conversion unit includes: a first region of a first conductivity type, the first region constituting a part of the first surface and being connected to a detection circuit configured to detect an avalanche breakdown; a second region of the first conductivity type, the second region disposed away from the first region; a third region of a second conductivity type opposite to the first conductivity type, the third region being disposed at a position closer to the second surface than the first region and the second region; and a fourth region disposed between the first region and the second region. The second and third regions serve as avalanche photodiodes. The first region and the second region are configured to be conductive to each other via the fourth region.

To provide a photoelectric conversion device that has an avalanche photodiode and can suppress image quality deterioration, in a photoelectric conversion device, a photoelectric conversion element including an avalanche photodiode for photoelectrically converting an optical image, an image generation unit configured to generate a first image based on a signal acquired by the photoelectric conversion element, an acquisition unit configured to acquire first characteristic information of the photoelectric conversion element, and a correction processing unit configured to perform first correction processing on the first image by using the first characteristic information are provided, and in the correction processing unit, weighting of the first correction processing is made different according to a magnitude of a pixel signal in the first image.

A controller for an avalanche photodiode sensor, including circuitry configured to: control a latch circuit to store one or more least significant bits of a counter value of a counter circuit at the end of a first frame, wherein the counter circuit is configured to count exposure time intervals of a frame in which an avalanche photodiode pixel has generated a light detection event; enable readout of the one or more least significant bits from the latch circuit in a second frame following the first frame; and enable readout of one or more most significant bits of the counter value from the counter circuit in the second frame.

A photodetector (90) having an exposure surface (91) has a first photodiode array (1) having a first light entry surface (11) and a second photodiode array (2) having a second light entry surface (21). The first photodiode array (1) has an avalanche photodiode (10). The second photodiode array (2) has a non-amplifying photodiode (10). The first light entry surface (11) and the second light entry surface (21) form sub-surfaces of the exposure surface (91).

The present invention discloses a visible light communication device based on a power line carrier circuit and a communication method thereof. The device includes: an Ethernet interface circuit, a power line carrier circuit, a switching switch, a signal attenuation circuit, a light source driving circuit, a light source, an avalanche photodiode, a photoelectric conversion circuit, a linear amplifier circuit, and a power detection circuit. The switching switch can switch the signal transmission mode from visible light communication to power line communication when the optical communication quality is poor, thereby improving the stability of the communication system. The power line carrier circuit modulates the signal in various ways, including OFDM, QPSK, BPSK, and ROBO. Compared with traditional visible light communication systems using OOK modulation, the communication rate and stability are significantly improved. The power detection circuit, the signal attenuation circuit, and the light source driving circuit cooperate to effectively control the power of the transmitted signal, enabling the signal to be transmitted without distortion. In addition, the power line can be replaced with a wire, twisted pair, etc., further improving the anti-interference capability and mobility.

The present invention provides a novel near-infrared single-photon detection system. The system is characterized in that it is composed of a gated signal output circuit (1), a switch control signal circuit (2), a logic gate control circuit (3), a capacitor (4), a bias voltage generation circuit (5), a near-infrared single-photon avalanche photodiode (6) and a signal readout circuit (7), wherein the signal readout circuit is composed of an amplifier (71) and a resistor (72). The present invention can be used to solve the signal loss problem generated when the near-infrared single-photon avalanche diode collects light signals in a gated quenching mode; and can be widely used in the field of extremely weak light detection such as optical time domain reflectometry, laser radar detection and medical imaging.

An optical sensor includes an integrated circuit including an array of time-to-digital converters and a first array of interconnects connected to the array of time-to-digital converters. A plurality of single photon avalanche photodiode circuits includes a second interconnect. Each of the plurality of single photon avalanche photodiode circuits corresponds to a single pixel. The plurality of single photon avalanche photodiode circuits are individually arranged on the integrated circuit with the second interconnect of the plurality of single photon avalanche photodiode circuits connected to a corresponding one of the first interconnects of the integrated circuit.

A photodetector device includes an avalanche photodiode array substrate 10 formed from compound semiconductor. A plurality of avalanche photodiodes 20 arranged to operate in a Geiger mode are two-dimensionally arranged on the avalanche photodiode array substrate 10. A circuit substrate 50 includes a plurality of output units 30 which are connected to each other in parallel to form at least one channel 40. Each of the output units 30 includes a passive quenching element 31 and a capacitative element 32. The passive quenching element 31 is connected in series to at least one of the plurality of avalanche photodiodes 20. The capacitative element 32 is connected in series to at least one of the avalanche photodiodes 20 and is connected in parallel to the passive quenching element 31.

In a signal processing circuit, an input terminal is configured to receive an analog signal output from an avalanche photodiode operating in Geiger mode. A comparison circuit outputs a signal based on a component exceeding a threshold among components a signal input to the comparison circuit. The adjustment circuit includes an AC coupling unit, a level shifter unit, and a reference value adjustment unit. The AC coupling unit establishes AC coupling between the input terminal and the comparison circuit. The level shifter unit adjusts the voltage of the signal input to the comparison circuit to a value lower than a reverse bias voltage applied to the avalanche photodiode. The reference value adjustment unit adjusts the reference value of the signal input to the comparison circuit.

The invention discloses a single-polarization self-coherent optical communication system and a polarization control method thereof, and relates to the field of optical fiber communication. The single-polarization self-coherent optical communication system mainly comprises a laser, a first polarization controller, an IQ modulator, a digital-to-analog converter, a second polarization controller, a polarization beam combiner, a lithium niobate polarization controller, a polarization beam splitter, a polarization-maintaining coupler, a coherent receiver, a variable optical attenuator, an avalanche photodiode and an analog-to-digital converter. By implementing the single-polarization self-coherent optical communication system and the polarization control method thereof provided by the invention, the complexity of a DSP (Digital Signal Processor) algorithm can be reduced, the power consumption and the cost of the system are reduced, and the stability of the system is improved.

The application relates to an avalanche diode single-photon detector and a preparation method thereof, in particular to a quantum dot-vertical linear avalanche diode single-photon detector and a preparation method thereof, and solves the problems of low detection efficiency of the existing single-photon detector and high preparation difficulty, high cost and limited effect of the existing method. + The detector comprises a detector N + substrate, a back electrode grown on the lower surface thereof, a plurality of quantum dot-vertical linear units arranged at intervals on the upper surface thereof, a passivation layer and a front electrode; the quantum dot-vertical linear unit comprises a semiconductor vertical linear structure, a porous nanomaterial layer and a quantum dot material layer; the semiconductor vertical linear structure is grown on the upper surface of the detector N + substrate; the porous nanomaterial layer covers the semiconductor vertical linear structure; the quantum dot material layer covers the porous nanomaterial layer; the passivation layer is filled between the quantum dot-vertical linear units; and the front electrode is grown on the part of the quantum dot-vertical linear unit extending out of the passivation layer.

A four-dimensional (4D) light-detection-and-ranging sensor using frequency modulated continuous wave is provided with an ultra-high velocity resolution. At a transmitting terminal, the hybrid waveform of a driving laser is used to minimize the phase noise generated by a distributed-feedback laser during wavelength scanning. The hybrid waveform is obtained by combining direct-current signal (not modulated) and alternating-current (AC) signal. The AC signal is a predistorted triangle or AC waveform for extracting location. The continuous wave (CW) extracts velocity. At a receiving terminal, a radar radio-frequency receiver is combined with an avalanche photodiode (APD) with multiple layers accumulated in series to obtain excellent responsivity and saturated current. The mixed waveform coordinated with the APD prevents Doppler shift frequency from being contaminated by low-frequency flicker noise. Thus, a good-quality 4D image is provided; and the use of the APD improves the pixel contrast between the object and background.

A photodetector 1 includes a light detection element 22, a comparison unit 9, a time measurement unit 11, and an energy monitor unit 12. The light detection element 22 includes a plurality of APDs 4 which operate in a non-linear region and are connected in parallel with each other. The comparison part 9 includes a plurality of comparators 16. The threshold values of the plurality of comparators 16 are different from each other. The time measurement unit 11 outputs, on the basis of one output signal SC among a plurality of output signals SC respectively outputted from the plurality of comparators 16, first information A1 indicating a time from a predetermined timing to when the one output signal SC is inputted. The energy monitor unit 12 generates second information A2 indicating the magnitude of the energy of the light pulse incident on the light detection element 22 on the basis of the plurality of output signals SC.

Disclosed herein are avalanche photodiodes (APDs) particularly useful for high-sensitivity Geiger-mode APDs formed using an array of micro-cells. The photodetector is formed on a semiconductor substrate of indium phosphide (InP) having epitaxial layers, including indium gallium arsenide (InGaAs) as the photodetecting layer, with n-doped InP to one side, and layers of InP incorporating p-doped regions on the opposite side. The p-doped regions may serve to define an array of micro-cells, which may be arranged in a hexagonal pattern. A well may be etched through the epitaxial structures, allowing an electrode that contacts the n-doped InP layer and another that contacts the p-doped InP regions to be patterned on the same side of the detector. Flip-chip bonding techniques can then attach the semiconductor wafer to a stronger support substrate, which may additionally be configured with electronic circuitry positioned to electrically contact the electrodes on the semiconductor wafer surface.

A single Geiger avalanche photodiode pixel interconnected with a readout circuit is decomposed to form M * M parallel pixel structures, the M * M parallel pixel structures are connected to a single pixel input stage of the readout circuit, and the time complementation relation between pixel avalanche events is utilized to enlarge the pixel avalanche events. The detection probability of the array single-photon detector pixel is improved, the photon detection dynamic range is expanded, the upper limit of the pixel photon saturation counting rate of the array single-photon detector can be remarkably improved, and the method is applied to the fields of high-dynamic-range laser three-dimensional imaging, space laser communication and the like.

The invention discloses a GaN-based bidirectional dual-waveband avalanche photodetector based on a back-to-back p-i-n structure, which comprises two back-to-back dual photodiode structures which share a p-type layer and grow on a substrate, namely a p-i-n structure taking GaN as an intrinsic layer and an SACM structure taking Al < 0.45 > Ga < 0.55 > N as an intrinsic layer. Compared with a traditional ultraviolet avalanche photodiode, the bidirectional dual-band avalanche photodiode can achieve avalanche multiplication under the forward bias voltage and the reverse bias voltage, and different working modes can be achieved by adjusting the external bias voltage. In a forward bias mode, the device is cut off at 365 nm, and in a reverse bias mode, the cut-off wavelength of the device is 281 nm, so that dual-band ultraviolet signal detection is realized, and the dual-band detection method is beneficial to accurate identification of signals and further popularization and application.