According to embodiments of the present invention, a pixel arrangement is provided. The pixel arrangement includes a plurality of pixels arranged adjacent to each other; and a substrate configured to receive the plurality of pixels, wherein each pixel of the plurality of pixels comprises a plurality of optical cells electrically coupled to each other; and an electrical interconnection electrically isolated from the plurality of optical cells, the electrical interconnection arranged to provide electrical communication between two separate conducting terminals external to the pixel.

A silicon photomultiplier device is provided. The device comprises a plurality of photosensitive cells each having a photo-detector, a quench resistive load and a first stage capacitive load. The device is arranged in a three electrode connection configuration comprising first and second electrodes arranged to operably provide a biasing of the device and a third electrode operably used to readout a signal from the device. A second stage capacitive load is operably coupled to two or more photosensitive cells.

The present disclosure includes devices for detecting photons, including avalanche photon detectors, arrays of such detectors, and circuits including such arrays. In some aspects, the detectors and arrays include a virtual beveled edge mesa structure surrounded by resistive material damaged by ion implantation and having side wall profiles that taper inwardly towards the top of the mesa structures, or towards the direction from which the ion implantation occurred. Other aspects are directed to masking and multiple implantation and/or annealing steps. Furthermore, methods for fabricating and using such devices, circuits and arrays are disclosed.

A Ge-on-Si photodetector constructed without doping or contacting Germanium by metal is described. Despite the simplified fabrication process, the device has responsivity of 1.24 A/W, corresponding to 99.2% quantum efficiency. Dark current is 40 nA at 4 V reverse bias. 3-dB bandwidth is 30 GHz.

A high sensitivity image sensor comprises an epitaxial layer of silicon that is intrinsic or lightly p doped (such as a doping level less than about 10.sup.13 cm.sup.3). CMOS or CCD circuits are fabricated on the front-side of the epitaxial layer. Epitaxial p and n type layers are grown on the backside of the epitaxial layer. A pure boron layer is deposited on the n-type epitaxial layer. Some boron is driven a few nm into the n-type epitaxial layer from the backside during the boron deposition process. An anti-reflection coating may be applied to the pure boron layer. During operation of the sensor a negative bias voltage of several tens to a few hundred volts is applied to the boron layer to accelerate photo-electrons away from the backside surface and create additional electrons by an avalanche effect. Grounded p-wells protect active circuits as needed from the reversed biased epitaxial layer.

An ultraviolet sensor includes a silicon photodiode array having a plurality of first pixel regions and a plurality of second pixel regions. A filter film is disposed on each of the first pixel regions so as to cover each first pixel region, except on each second pixel region. The filter film lowers transmittance in a detection target wavelength range in the ultraviolet region. Each of each first pixel region and each second pixel region includes at least one pixel having an avalanche photodiode to operate in Geiger mode, and a quenching resistor connected in series to the avalanche photodiode. Each of the quenching resistors in the plurality of first pixel regions is connected through a first signal line to a first output terminal. Each of the quenching resistors in the plurality of second pixel regions is connected through a second signal line to a second output terminal.

An avalanche photodiode for detecting ultraviolet radiation, including: a silicon carbide body having a first type of conductivity, which is delimited by a front surface and forms a cathode region; an anode region having a second type of conductivity, which extends into the body starting from the front surface and contacts the cathode region; and a guard ring having the second type of conductivity, which extends into the body starting from the front surface and surrounds the anode region.

A method of detecting an optical signal, comprising the steps of: providing an avalanche photodiode (APD) comprising a multiplication region capable of amplifying an electric current, said multiplication region, in operation, having a first ionization rate for electrons and a second ionization rate for holes, wherein said first ionization rate is different in magnitude from said second ionization rate, and exposure to the optical signal causes an impulse response; exposing the APD to a modulating optical signal; providing an external circuit that induces an APD bias to the multiplication region; providing an external circuit for amplifying and processing an electric signal from the avalanche photodiode; and modulating the APD bias in a manner that is correlated with the optical signal.

A p.sup. type semiconductor substrate 20 has a first principal surface 20a and a second principal surface 20b opposed to each other and includes a photosensitive region 21. The photosensitive region 21 is composed of an n.sup.+ type impurity region 23, a p.sup.+ type impurity region 25, and a region to be depleted with application of a bias voltage in the p.sup. type semiconductor substrate 20. An irregular asperity 10 is formed in the second principal surface 20b of the p.sup. type semiconductor substrate 20. An accumulation layer 37 is formed on the second principal surface 20b side of the p.sup. type semiconductor substrate 20 and a region in the accumulation layer 37 opposed to the photosensitive region 21 is optically exposed.

A sensing apparatus includes a sensor and a processor. The sensor includes at least one light sensitive detector. The processor determines a first control value to control a voltage differential across the at least one light sensitive detector, and compares the first control value with a reference value associated with a reference temperature. Based on the comparison, the processor provides adjustment information for adjusting at least one output of the sensing apparatus, and an operating parameter of the sensing apparatus other than the voltage differential.