266 results about "Single-photon avalanche diode" patented technology

An integrated imager circuit comprising a monolithic array of single photon avalanche diodes (SPADs) for capturing an image of a scene when said scene is hit by an optical pulse, said array comprising: a plurality of SPADs connected to 2D readout circuits determines the intensity of the light reflected by said scene by counting the number of photons received by said SPADs during a period of time, a plurality of SPADs connected to 3D readout circuits determines the distance to said scene by determining the elapsed time between the emission of each pulse and reception of the corresponding reflected photons.

An integrated circuit (1) has an array of single photon avalanche diodes (SPADS), a plurality of read-out circuits, each SPADS being coupled to one read-out circuit, wherein at least some of the read-out circuits comprise time-to-digital converters (TDC) and/or a digital asynchronous counter. The plurality of SPADS are coupled to one single read-out circuit. The read-out circuit may have a transformer for decoupling the SPAD from other parts of the read-out circuit.

A single photon avalanche diode for use in a CMOS integrated circuit includes a deep n-well region formed above a p-type substrate and an n-well region formed above and in contact with the deep n-well region. A cathode contact is connected to the n-well region via a heavily doped n-type implant. A lightly doped region forms a guard ring around the n-well and deep n-well regions. A p-well region is adjacent to the lightly doped region. An anode contact is connected to the p-well region via a heavily doped p-type implant. The junction between the bottom of the deep n-well region and the substrate forms a multiplication region when an appropriate bias voltage is applied between the anode and cathode and the guard ring breakdown voltage is controlled with appropriate control of the lateral doping concentration gradient such that the breakdown voltage is higher than that of the multiplication region.

A measuring device for optically measuring a distance to a target object includes an emitter device for emitting an optical measuring beam to the target object, a capturing device including a detection surface for detecting an optical beam returned by the target object, and an evaluation device. The detection surface has a plurality of pixels, each pixel having at least one SPAD (single photon avalanche diode) and each of the plurality of pixels is connected to the evaluation device. The emitting device and the capturing device are configured in such a manner that the optical measurement beam returned by the target object simultaneously illuminates a plurality of pixels. The evaluation device is configured in order to determine the distance between the measuring device and the target object based on the evaluation of detection signals of several pixels.

A Raman spectrometer that employs a time-gated single photon avalanche diode array as a sensor is described. The spectrometer can also perform fluorescence spectroscopy and laser induced breakdown spectroscopy (LIBS). A laser is used to provide an excitation signal to excite a specimen of interest. A spectrometer is used to separate the various intensities over a range of wavelengths, which are then caused to impinge on the array to be recorded. The time-gated single photon avalanche diode array is triggered in synchrony with the excitation signal so as to allow time resolution of the response of the sample of interest to the excitation. The array can be time-gated to resolve signals that have shorter durations as a function of time while excluding signals that have a longer time duration. Raman and LIBS signals can be observed even from specimens that fluoresce strongly.

The invention discloses an integrated gating active quenching/restoring circuit. The integrated gating active quenching/restoring circuit comprises a quick detection circuit, a pulse generation circuit, a pixel control circuit, a quenching circuit and a restoring circuit, wherein the quick detection circuit is used for processing a detected anode current signal of an SPAD (Single Photon Avalanche Diode) into a pulse signal, the pulse signal can be output through the pulse generation circuit, the pixel control circuit is controlled by an output signal and a gating signal of the pulse generation circuit, the restoring circuit and the quenching circuit are respectively controlled by outputs of the pixel generation circuit, outputs of the restoring circuit and the quenching circuit can be fed back to an anode of the SPAD, and the restoring and the quenching of the SPAD can be controlled. According to the integrated gating active quenching/restoring circuit disclosed by the invention, by adopting a gating control method, the dark counting rate of the SPAD can be effectively reduced, the quenching time can be controlled by the pulse generation circuit, and the integrated gating active quenching/restoring circuit has the advantages of compact area and low power consumption.

The present invention relates generally to methods and devices of generating an electrical representation of at least one object in a scene in the real word. The detail real-time imager for the representation of a scene of a real world comprises:—at least an illuminator (0501-0511) of said scene providing at least a series of ultra-short power laser pulses with time-related positions; and—a receiver (0515-0523) of a SPAD Single Photon Avalanche Diode detector array according to the method of the invention and associated to at least said series of ultra-short power laser pulses of said illuminator.

The invention aims at providing a quenching and reading circuit for a single photon avalanche diode imaging device, which is composed of three modules including a quenching circuit, a holding circuit and a reading circuit, wherein the quenching circuit is used for generating a pulse signal having the same frequency with an incident photon signal, the holding circuit is used for generating a reset signal, the phase of the reset signal is different from the phase of quenching output, the frequency of the reset signal is the same with the frequency of the quenching output, and the reading circuit is used for performing count processing on the quenching output pulse signal and outputting the signal in a linear and logarithmic mode. Quenching processing is performed on an avalanche diode after photon incidence by utilizing the quenching circuit, pulse signal output with the same frequency as incident photons is generated and directly sent into the reading circuit, the reading circuit selects to output a final result in a linear or a logarithmic mode according to the control of a plus signal, and simultaneously the quenching output pulse is delayed to keep the frequency unchanged and the phase changed to serve as the reset signal for controlling the staring or stopping of quenching.

Disclosed is a single-photon-level resolution ratio sensor unit structure based on the standard CMOS technology. The single-photon-level resolution ratio sensor unit structure uses an SPAD. According to the single-photon-level resolution ratio sensor unit structure, basically, a deep N-well (3) is arranged above a P-type silicon substrate (4), a P-well area (2) is formed above the deep N-well (3) and wrapped by the deep N-well (3), an anode contact (9) is connected to the P-well area (2) through a heavy-doping P-well area (1), a cathode contact (10) is connected to an N-well area (6) and the deep N-well (3) through a heavy-doping N-well area (5), a shallow trench isolation area (7) is located between the P-well area (2) and the N-well area (6) to isolate a P-well from an N-well, a P-type doped protection ring (8) surrounds the shallow trench isolation area (7) so as to restrain dark noise caused by defects in shallow trench isolation, and a PN junction (11) is arranged between the bottom of the P-well area (2) and the deep N-well (3); the PN junction generates a high-voltage area when proper bias voltage is applied between the cathode and the anode, and an SPAD multiplication area is formed so as to explore photons; the breakdown voltage of the edge of the PN junction is higher than that of the SPAD plane multiplication area by controlling the concentration gradient of the deep N-well (3).

The invention discloses a high-detective-efficiency single photon avalanche diode (SPAD) detector array unit. The array unit adopts a surrounded type SPAD structure with a deep P well protected by a P-injection layer, a P buried layer and a P-buried layer, i.e., the deep P well is formed in a P type substrate through ion injection, two buried layer regions, i.e., a P buried layer region 3 and a P-buried layer region 4, are arranged in the deep P well, and the upper part of the P-buried layer region 4 is surrounded by a P-injection region 8. The structure of the array unit can effectively improve the photon detection efficiency of an SPAD device, and the dark count rate is very low, so that the overall performance of an SPAD detector is improved very well.

The invention provides an analog signal reading method in terms of a single photon avalanche diode (SPAD) detector. The analog signal reading method comprises three successive processes of resetting, counting and signal reading. During the resetting, a capacitor is firstly charged to the power source voltage. During the counting after the resetting, a counting circuit counts for once every time an avalanche pulse signal generated by the SPAD detector is input, and charges on the capacitor are discharged for once. During a period of counting, the voltage changing value on the capacitor is proportional to changing of the quantity of photons detected by the SPAD detector during the time, and the number of the photons detected by the SPAD can be calculated. The signal reading stage can be entered after counting is finished, and the voltage value on the capacitor can be read through a voltage follower. Additionally, counting and reading of the analog signals can be performed for twice before and after exposure of the detector, and influence of dark counting can be eliminated by subtracting the analog signals read in two times to obtain accurate photon counting.

It is disclosed a method for controlling the spectral response of light sensitive semiconductor elements in an array (8) using an electric control signal (V_op) applied to said semiconductor elements. The light sensitive semiconductor elements could be a single photon avalanche diode (81) operating In Geiger mode. The invention as well refers to an Image sensor comprising at least one light sensitive semiconductor elements and a circuit for applying a control voltage (V_op) to said semiconductor element so as to change its spectral response. Without being limiting, the sensor of the invention could be part of a digital camera, video camera, 3D image sensors, scanner, video telephone, autofocus system, medical image acquisition system, etc.

The invention discloses a Brillouin optical time domain reflectometer for single-photon detection based on an edged filter method, which comprises a narrow linewidth laser (1), a pulse modulator (2), a circulator (3), a sensing optical fiber (4), an optical fiber module (5), 3dB coupler (6), a linear edged filter (7), an InGaAs/InP SPAD (single-photon avalanche diode) detector group (8), a signal generator (9), a data processing module (10) and a pulse signal generator (11), wherein the InGaAs/InP SPAD detector group (8) includes two or three InGaAs/InP SPAD detectors. The InGaAs/InP SPAD detector group with a high counting rate and high sensitivity is used as a detection unit, Brillouin frequency shift information is acquired by the edged filter method, time correlation single-photon counting technology is adopted by the data processing module (10), limitations on the bandwidth and sensitivity of a traditional detector are broken through, spatial resolution and measuring precision of the reflectometer can be simultaneously improved, and temperature and strain are simultaneously sensed.

The invention belongs to the technical field of electronic technologies and photoelectronic imaging technologies, in particular relates to a single-photon avalanche diode and a three-dimensional CMOS (Complementary Metal Oxide Semiconductor) image sensor based on the diode. The single-photon avalanche diode of the invention improves the traditional rectangular photosensitive PN junction into a regular octagon and can conveniently and simply weaken edge breakdown and improve gain uniformity. A two-dimensional pixel array of the three-dimensional CMOS image sensor based on the diode comprises unit pixels of the regular octagon-shaped single-photon avalanche diode and is arrayed in a honeycomb-shape, thereby being convenient for interpolation and improving resolution in horizontal and vertical direction.

An imaging sensor system includes a single photon avalanche diode (SPAD) imaging array including N pixels formed in a first semiconductor layer of a first wafer. Substantially an entire thickness of the first semiconductor layer of each pixel is fully depleted such that a multiplication region included in each pixel near a front side is configured to be illuminated with photons through a back side and through the substantially entire thickness of the fully depleted first semiconductor layer. Deep n type isolation regions are disposed in the first semiconductor layer between the pixels to isolate the pixels. N digital counters are formed in a second semiconductor layer of a second wafer that is bonded to the first wafer. Each of the N digital counters is coupled to the SPAD imaging array and coupled to count output pulses generated by a respective one of the pixels.

The invention discloses an annular-gate single-photon avalanche diode capable of preventing edge breakdown and a preparation method of the annular-gate single-photon avalanche diode capable of preventing edge breakdown. A heavily-doped N-region and a P-well region jointly form an N<+>/P-well type photodiode structure; the heavily-doped N-region also serves as a cathode contact region of an photoelectric detector; a P-well contact region is a heavily-doped P-type region and serves as an anode contact region of the photoelectric detector; in an electric field of an avalanche region, the heavily-doped N<+> region points to the P-well region, so that electrons generated below a depletion region drift into the avalanche regions more easily, and sensitivity of the detector is improved; a deep N-well serves as a local substrate of the photodiode and is used for isolating the photodiode from other electron devices; an oxidation layer region comprises a gate oxide portion and a field oxide portion; a polysilicon gate is an annular region enclosing the photodiode; a depletion layer of an N<+>/P-well type photodiode serves as a main photosensitive region during single-photon detection. The annular-gate single-photon avalanche diode is capable of preventing edge breakdown from affecting normal operation of an SPAD (single-photon avalanche diode).