Abstract: An inspection system that includes a memory; a configurable acquisition channel; a controller that is adapted to: (a) determine, in response to a first frequency wise relationship between the first noise power spectrum and the first signal power spectrum, a first configuration of the configurable acquisition channel; and (b) determine, in response to a second frequency wise relationship between the second noise power spectrum and the second signal power spectrum, a second configuration of the configurable acquisition channel; and wherein the configurable acquisition channel is adapted to: (a) acquire the image of the first area of the inspected object while being configured according to the first area configuration, and (b) acquire the image of the second area while being configured according to the second area configuration.

Abstract: A sensing element that may include (a) a PIN diode that may include an anode that is coupled to an anode contact; a cathode that is coupled to a cathode contact; a semiconductor portion that has a sensing region; and an insulator that is positioned between the cathode contact and the anode contact; and (b) a shielding element. The insulator, the cathode contact and the anode contact are positioned between the shielding element and the semiconductor portion. The shielding element is shaped and positioned to facilitate radiation to impinge onto the sensing region of the semiconductor portion while at least partially shielding the insulator from electrons that are emitted from the sensing region.

Abstract: A device that may include a DC power supply coupled to a fixed current source; an APD; a DC voltage regulator that comprises a regulating transistor, arranged to maintain a regulated voltage at a fixed value over different APD currents; a temperature control module that is arranged to maintain a portion of the temperature control module at a fixed temperature; and compensation circuit that comprises a compensation component that is thermally coupled to the APD. A voltage drop over the compensation component is smaller than a voltage drop over the APD. A sum of (a) a current that pass through the APD and (b) a current that passes through the compensation component is fixed.

Abstract: A device that may include A DC power supply coupled to a fixed current source; an avalanche photo-diode (APD); a DC voltage regulator that comprises a regulating transistor; wherein the DC voltage regulator is arranged to (a) maintain a regulated voltage at a fixed value, and (b) output the regulated voltage; and a temperature control module that is arranged to maintain a portion of the temperature control module at a fixed temperature; wherein the DC voltage regulator and the APD are electrically coupled in parallel to each other, so that a sum of currents that pass through the APD and the regulating transistor equals a fixed current supplied by the fixed current source; and wherein the portion of the temperature control module is thermally coupled to the DC voltage regulator and to the APD, and wherein APD and the regulating transistor are thermally coupled to each other.

Abstract: A device that may include A DC power supply coupled to a fixed current source; an avalanche photo-diode (APD); a DC voltage regulator that comprises a regulating transistor; wherein the DC voltage regulator is arranged to (a) maintain a regulated voltage at a fixed value, and (b) output the regulated voltage; and a temperature control module that is arranged to maintain a portion of the temperature control module at a fixed temperature; wherein the DC voltage regulator and the APD are electrically coupled in parallel to each other, so that a sum of currents that pass through the APD and the regulating transistor equals a fixed current supplied by the fixed current source; and wherein the portion of the temperature control module is thermally coupled to the DC voltage regulator and to the APD, and wherein APD and the regulating transistor are thermally coupled to each other.

Abstract: A sensing element that may include (a) a PIN diode that may include an anode that is coupled to an anode contact; a cathode that is coupled to a cathode contact; a semiconductor portion that has a sensing region; and an insulator that is positioned between the cathode contact and the anode contact; and (b) a shielding element. The insulator, the cathode contact and the anode contact are positioned between the shielding element and the semiconductor portion. The shielding element is shaped and positioned to facilitate radiation to impinge onto the sensing region of the semiconductor portion while at least partially shielding the insulator from electrons that are emitted from the sensing region.

Abstract: A photo-detector and method for operating same: the photo-detector comprises a photomultiplier tube comprising a plurality of electrodes, each having a photocathode, an anode, a first dynode, intermediate dynodes and a last dynode; and a biasing circuit that comprises a sequence of voltage follower elements, a voltage divider and a current source. The voltage divider is coupled across a high voltage power supply and different dynodes are coupled to different ones of the voltage follower elements, control inputs of which are coupled to different junctions of the voltage divider. The current source is coupled to the voltage divider, to the sequence of the voltage follower elements and to the cathode. The anode is coupled to a load element coupled to a positive pole of the high voltage power supply and arranged to receive an output signal of the anode and convert it to an output signal of the photo-detector.

Abstract: A photo-detector and method for operating same: the photo-detector comprises a photomultiplier tube comprising a plurality of electrodes, each having a photocathode, an anode, a first dynode, intermediate dynodes and a last dynode; and a biasing circuit that comprises a sequence of voltage follower elements, a voltage divider and a current source. The voltage divider is coupled across a high voltage power supply and different dynodes are coupled to different ones of the voltage follower elements, control inputs of which are coupled to different junctions of the voltage divider. The current source is coupled to the voltage divider, to the sequence of the voltage follower elements and to the cathode. The anode is coupled to a load element coupled to a positive pole of the high voltage power supply and arranged to receive an output signal of the anode and convert it to an output signal of the photo-detector.

Abstract: A method and system for the compensation of nonuniformity among a plurality of light sensing diodes adapted to convert light to a current output. A system embodiment includes a plurality of trans-impedance amplifier circuits, each trans-impedance amplifier circuit having an op-amp, and an impedance connecting an output of the op-amp to a first input of the op-amp, and a plurality of variable voltage source. The current output of each sensing diode is coupled to a corresponding trans-impedance amplifier circuit by an electrical connection to the first input of corresponding op-amp. A second input of the corresponding op-amp is coupled to a corresponding adjustable voltage source. The output of the corresponding op-amp is a signal responsive to a sensing voltage, and to a voltage signal provided by the corresponding adjustable voltage source, the sensing voltage being responsive to the current output of a corresponding sensing diode.

Abstract: A method and system for controlling the characteristics of multiple sensors. The system includes: multiple sensing diodes adapted to convert light to current; whereas each sensing diode is connected to an output circuit that includes a trans-impedance amplifier connected to an adjustable voltage source; wherein changes in a voltage signal provided by the adjustable voltage source affect a sensing diode characteristic.

Abstract: In a method and apparatus for compensating for static and dynamic inaccuracies in an optical scanner used in a typical surface inspection system, the scanner may have a scanning axis and a cross-scanning axis. A surface of an inspection article is scanned along a scanning axis and a scanning axis signal is output at predetermined distances along this axis. The scanning axis signal may be used to determine a speed of relative movement between the scanner and the inspection article. A jitter signal may be output whenever the scanner deviates from the scanning axis, and this signal may be used to calculate the amount of deviation. Information, such as the speed of relative movement, scan line resolution, and a scanning axis static position error may be used to generate a scan line. A generated scan line may be shifted to compensate for a cross-scanning axis error.

Abstract: In a method and apparatus for compensating for static and dynamic inaccuracies in an optical scanner used in a typical surface inspection system, the scanner may have a scanning axis and a cross-scanning axis. A surface of an inspection article is scanned along a scanning axis and a scanning axis signal is output at predetermined distances along this axis. The scanning axis signal may be used to determine a speed of relative movement between the scanner and the inspection article. A jitter signal may be output whenever the scanner deviates from the scanning axis, and this signal may be used to calculate the amount of deviation. Information, such as the speed of relative movement, scan line resolution, and a scanning axis static position error may be used to generate a scan line. A generated scan line may be shifted to compensate for a cross-scanning axis error.