37 results about "Geiger mode avalanche photodiode" patented technology

A light wave rangefinder includes a light transmitting optical system for directing a laser pulse at a target, and a light receiving optical system for receiving reflected light from the target, including a Geiger-mode avalanche photodiode (APD) array and a non-imaging optical device. The non-imaging optical device is positioned between the received reflected light and the APD array, and is configured to uniformly distribute the received reflected light across the APD array. The APD array is uniformly illuminated by a single received reflected laser pulse, producing a plurality of Geiger-mode avalanche events.

A photon-counting Geiger-mode avalanche photodiode intensity imaging array includes an array of pixels, each having an avalanche photodiode. A pixel senses an avalanche event and stores, in response to the sensed avalanche event, a single bit digital value therein. An array of accumulators are provided such that each accumulator is associated with a pixel. A row decoder circuit addresses a pixel row within the array of pixels. A bit sensing circuit converts a precharged capacitance into a digital value during read operations.

A Geiger-mode avalanche photodiode may include an anode, a cathode, an output pad electrically insulated from the anode and the cathode, a semiconductor layer having resistive anode and cathode regions, and a metal structure in the semiconductor layer and capacitively coupled to a region from the resistive anode and resistive cathode regions and connected to the output pad. The output pad is for detecting spikes correlated to avalanche events.

Following exposure to an external light source, determining: 1) the fertility of an avian egg by measuring the photon intensity (photons per second) of the egg's biophoton and luminescence; and 2) the gender of an avian egg by measuring the photon spectrum of the egg's biophoton emission and luminescence. The external light source is either an incandescent, fluorescent, LED, (pulsed or continuous wave) monochromatic or dichromatic laser light source. The detector of the photon intensity is either a low light sensing photomultiplier tube (PMT), silicon based photon counting sensor, or Geiger-mode avalanche photodiode detector. The detector of the photon spectrum is a spectrometer. Following exposure to the referenced light sources, fertile avian eggs will exhibit a higher intensity of photons than that of unfertilized avian eggs, and avian eggs of the female gender will emit a different spectrum of photons than will avian eggs of the male gender.

An avalanche photodiode detector is provided with a substrate including an array of avalanche photodiodes. An optical interface surface of the substrate is arranged for accepting external input radiation. There is provided at least one cross-talk blocking layer of material including apertures positioned to allow external input radiation to reach photodiodes and including material regions positioned for attenuating radiation in the substrate that is produced by photodiodes in the array. Alternatively at least one cross-talk blocking layer of material is disposed on the optical interface surface of the substrate to allow external input radiation to reach photodiodes and attenuate radiation in the substrate that is produced by photodiodes in the array. At least one cross-talk filter layer of material can be disposed in the substrate adjacent to the photodiode structures, including a material that absorbs radiation in the substrate that is produced by photodiodes in the array.

A multi-pixel photodetector array may include a semiconductor substrate having a back side and a front side, Geiger mode avalanche photodiodes (GM-APDs) on the semiconductor substrate, each including an anode contact, and a common cathode for the GM-APDs and having a first connection lead on the backside of the semiconductor substrate. The multi-pixel photodetector array may include a second connection lead, and a common anode on the front side of the semiconductor substrate and configured to couple in common the anode contacts of the GM-APDs to the second connection lead. Each GM-APD may be configured to generate, when a photon impinges thereon, a current pulse of different shape for discrimination by an external circuit connected to the common cathode and the common anode.

Embodiments of the present invention include complementary metal-oxide-semiconductor (CMOS) readout architectures for photon-counting arrays with a photon-counting detector, a digital counter, and an overflow bit in each of the sensing elements in the array. Typically, the photon-counting detector is a Geiger-mode avalanche photodiode (APD) that emits brief pulses every time it detects a photon. The pulse increments the digital counters, which, in turn, sets the overflow bit once it reaches a given count. A rolling readout system operably coupled to each sensing element polls the overflow bit, and, if the overflow bit is high, initiates a data transfer from the overflow bit to a frame store. Compared to other photo-counting imagers, photon-counting imagers with counters and overflow bits operate with decreased transfer bandwidth, high dynamic range, and fine spatial resolution.

The invention provides a three-dimensional laser imaging method based on a photon counting compressive sampling phased array, which is applicable to the fields of all-weather target identification, high-precision terrain survey, precise nondestructive examination and the like, and belongs to the technical field of laser imaging and image processing. The three-dimensional laser imaging method includes steps that at first, a pulse signal generator generates pulse signals and drives a laser device to transmit laser pulse, and a liquid crystal optical phased array is adopted to modulate illuminating laser via a certain measurement matrix so as to illuminate for a target; optical pulse reflected by the target is received by a Geiger-mode avalanche photodiode, a time-correlated single photon counter is used for recording the numbers of photons returned at different time intervals, and the numbers of the photons returned at different time intervals are integrated so as to obtain a measured vector quantity; and the measured matrix and the measured vector quantity are brought into a compressive sampling recovery algorithm, so that a three-dimensional image of the target is reconstructed. The three-dimensional laser imaging method has a good practical value and a wide application prospect in the technical field of laser imaging and digital image processing.

An array of Geiger-mode avalanche photodiodes is formed in a die and includes: an internal dielectric structure, arranged on the die; and an external dielectric region arranged on the internal dielectric structure. The external dielectric region is formed by an external material that absorbs radiation having a wavelength that falls in a stop-band with low wavelength and transmits radiation having a wavelength that falls in a pass-band with high wavelength, at least part of the pass-band including wavelengths in the infrared. The internal dielectric structure is formed by one or more internal materials that substantially transmit radiation having a wavelength that falls in the stop-band and in the pass-band and have refractive indices that fall in an interval having an amplitude of 0.4. In the stop-band and in the pass-band the external dielectric region has a refractive index with the real part that falls in the above interval.

An array of Geiger-mode avalanche photodiodes is formed in a die and includes: an internal dielectric structure, arranged on the die; and an external dielectric region arranged on the internal dielectric structure. The external dielectric region is formed by an external material that absorbs radiation having a wavelength that falls in a stop-band with low wavelength and transmits radiation having a wavelength that falls in a pass-band with high wavelength, at least part of the pass-band including wavelengths in the infrared. The internal dielectric structure is formed by one or more internal materials that substantially transmit radiation having a wavelength that falls in the stop-band and in the pass-band and have refractive indices that fall in an interval having an amplitude of 0.4. In the stop-band and in the pass-band the external dielectric region has a refractive index with the real part that falls in the above interval.

The photo detector array is configured to generate pulses with short rise and fall times because each Geiger mode avalanche photodiode includes an anode contact, a cathode contact, an output contact electrically insulated from the anode and cathode contacts, a semiconductor layer, and at least one shield or metal structure in the semiconductor layer capacitively coupled to the semiconductor layer and coupled to the output contact. The output contacts of all Geiger mode avalanche photodiodes are connected in common and are configured to provide for detection of spikes correlated to avalanche events on any avalanche photodiode of the array.

A proximity sensor may include an array of Geiger mode avalanche photodiodes, each including an anode contact and a cathode contact. A common cathode contact may be coupled to the cathode contacts of the array to define a first connection lead at a back side of the array. A common anode collecting grid contact may be coupled to the anode contacts of the array to define a second connection lead of the array. Circuitry may be coupled with the first and second connection leads and configured to sense at least one of a dark current and a rate of current spikes generated in dark conditions, and generate an output signal representing, an estimated distance of an object from the array upon the sensing.

An imaging radiation detector includes a scintillator coupled to an array of photodiodes operating in Geiger mode. The array is divided into separate detector pixels, each of which is composed of a multiplicity of photodiode cells with their outputs tied together. While each of the cells operates independently in a binary or digital mode, by tying together the outputs of a multiplicity of adjacent photodiode cells forming a single pixel, the sum of the outputs is proportional to the intensity of generated scintillation photons, similar to the output of a PMT. Appropriate quenching circuitry is provided to rapidly reset the photodiodes after scintillation photon detection.

The invention provides a method and a laser radar system for measuring the depth of water, and relates to the technical field of laser detection, aiming at solving the problems that the prior art is high in cost, low in efficiency and low in measurement accuracy. The method is characterized in that liner polarization modulation is carried out on a laser pulse signal sent by a laser, and the laser pulse signal subjected to the liner polarization modulation is vertically transmitted to the water surface by an optical transmitting system; an echo signal is received by using an optical receiving system and is divided into two beams by using a polarization beam splitter; two Geiger mode-avalanche photodiode (Gm-APD) single-photon detectors are respectively used for detecting the arrival time of the two beams of light; a signal processing module calculates the depth of water according to the difference of the arrival time of the two beams of light. The method is low in cost of used optical devices, simple and easy in measurement process, simple in signal processing process and high in measurement efficiency. The Gm-APD single-photon detectors can effectively improve the measuring sensitivity and even also can be used for measuring a single-photon echo signal in a deeper water area, so that the application scopes of the method and the system which are provided by the invention are expanded.

The invention discloses a photon counting laser radar based on true random coding, and belongs to the technical field of the laser radar. The true random coding greatly reduces the system volume and cost and overcomes the influence on the system ranging performance by the detector dead time while reserving the advantage that the traditional pseudo random coding photon counting laser radar system is low in transmitting power, fast in imaging speed and capable of overcoming distance ambiguity, and the true random coding photon counting laser radar system has extremely high crosstalk-resisting capacity. The radar mainly comprises two avalanche photodiodes in Geiger model, a pulse shaping circuit, a laser device, an optical system, an external clock, a photon counting module, and a signal processing module. The traditional signal generator is replaced with the single-photon detector, the practical value of the system is greatly improved, and the laser radar is extensively applied to the target ranging and imaging field.

An embodiment of array of Geiger-mode avalanche photodiodes, wherein each photodiode is formed by a body of semiconductor material, having a first conductivity type and housing an anode region, of a second conductivity type, facing a top surface of the body, a cathode-contact region, having the first conductivity type and a higher doping level than the body, facing a bottom surface of the body, an insulation region extending through the body and insulating an active area from the rest of the body, the active area housing the anode region and the cathode-contact region. The insulation region is formed by a first mirror region of polycrystalline silicon, a second mirror region of metal material, and a channel-stopper region of dielectric material, surrounding the first and second mirror regions.

A photodetector includes a Geiger mode avalanche photodiode, which includes a body of semiconductor material, which is delimited by a front surface. The avalanche photodiode further includes: a cathode region having a first type of conductivity, which forms the front surface; and an anode region having a second type of conductivity, which extends in the cathode region starting from the front surface. The photodetector further includes: a dielectric region, arranged on the front surface; a quenching resistor, which extends on the dielectric region, is electrically connected to the anode region, and is laterally spaced apart with respect to the anode region; and an optical-isolation region, which extends through the dielectric region and laterally delimits a portion of the dielectric region, the anode region extending underneath the portion of the dielectric region, the optical-isolation region being moreover interposed between the portion of the dielectric region and the quenching resistor.

In at least one embodiment, a Geiger-mode avalanche photodiode, including a semiconductor body, is provided. The semiconductor body includes a semiconductive structure and a front epitaxial layer on the semiconductive structure. The front epitaxial layer has a first conductivity type. An anode region having a second conductivity type that is different from the first conductivity type extends into the front epitaxial layer. The photodiode further includes a plurality of gettering regions in the semiconductive structure.

A device for detecting a chemical species including a Geiger mode avalanche photodiode, which comprises a body of semiconductor material delimited by a front surface. The semiconductor body includes: a cathode region having a first type of conductivity, which forms the front surface; and an anode region having a second type of conductivity, which extends within the cathode region starting from the front surface. The detection device further includes: a dielectric region, which extends on the front surface; and a sensitive region, which is arranged on top of the dielectric region and electrically coupled to the anode region and has a resistance that depends upon the concentration of the chemical species.

A system for generating a 3D image of a scene includes a transmitter, a receiver, a scanning system and a data processing computer. The transmitter includes a pulsed laser generating optical pulses for illuminating the scene, and the optical pulses have a pulse width of less than 20 nanoseconds and a pulse repetition frequency in the range of 20 kHz to 200 kHz. The receiver includes a sensor to detect light scattered and reflected from the scene, and the sensor comprises one or more arrays of Geiger-mode avalanche photodiodes. The scanning system allows the transmitter and receiver subsystem field-of-view (FOV) to interrogate a field-of-regard (FOR) of at least 30 degrees, with update rates faster than once per 5 seconds, resolution higher than 1 million resolution elements per second, and FOR aspect ratios of 1:10 to 1:1. The data processing computer continuously generates 3D point clouds with latency less than 5 seconds, and generates alarms indicating anomalous activity within the scene.