A sensor for discriminating between wavelength regions in an electromagnetic spectrum is disclosed. The sensor comprising a substrate, a sensing element supported on a surface of the substrate, and at least one pair of terminal electrodes disposed on the substrate surface in mutually spaced apart and opposing relation, and in electrical contact with the sensing element, wherein the sensing element is responsive to electromagnetic radiation to yield a change in photocurrent measured between the terminal electrodes as a function of an intensity of the electromagnetic radiation impinging thereon, wherein a positive dependency on the intensity corresponds to a first wavelength region and a negative dependency on the intensity corresponds to a second wavelength region.

Method, sterilization system and robotic system for improving duty cycle of Ultraviolet (UV) emitter modules disinfecting closed environment. Sterilization system includes robotic system and plurality of UV emitter modules. Robotic system receives signal corresponding to discharge of battery from one of plurality of UV emitter modules. Each of plurality of UV emitter modules includes UV light source for disinfecting closed environment. Robotic system detects location of UV emitter module amongst plurality of UV emitter modules and maneuvers to location of UV emitter module, mounts UV emitter module and maneuvers UV emitter module to charging dock for charging battery of UV emitter module. After charging, robotic system maneuvers UV emitter module to pre-defined area for disinfecting pre-defined area of closed environment. Robotic system includes battery charged through UV emitter module when UV emitter module is getting charged, or when UV emitter module mounted to robotic system includes battery that is fully charged.

A UV sensor includes a GaN stack including a low-resistance GaN layer formed over a nucleation layer, and a high-resistance GaN layer formed over the low-resistance GaN layer, wherein a 2DEG conductive channel exists at the upper surface of the high-resistance GaN layer. An AlGaN layer is formed over the upper surface of the high-resistance GaN layer. A source contact and a drain contact extend through the AlGaN layer and contact the upper surface of the high-resistance GaN layer (and are thereby electrically coupled to the 2DEG channel). A drain depletion region extends entirely from the upper surface of the high-resistance GaN layer to the low-resistance GaN layer under the drain contact. An electrical current between the source and drain contacts is a function of UV light received by the GaN stack. An electrode is connected to the low-resistance GaN layer to allow for electrical refresh of the UV sensor.

To calculate a probability of an optical sensor's irregular discharge, a light detection system includes an optical sensor, an application voltage generating circuit that applies a drive pulse voltage to the optical sensor, a discharge determining portion that detects the optical sensor's discharge, a discharge probability calculating portion that calculates a discharge probability for each of first and second states in which the optical sensor is shielded from light and the drive pulse voltage's width in the second state is different from the first state, a sensitivity parameter storing portion storing the drive pulse voltage's reference pulse width as the optical sensor's sensitivity parameter, and another discharge probability calculating portion that calculates an irregular discharge's probability that occurs without depending on the optical sensor's received light quantity, based on the sensitivity parameter, and the discharge probabilities calculated and the drive pulse voltage's widths in the first and second states.

In various aspects, an apparatus for an electron-beam powder bed fusion (EB-PBF) printer includes a radiation collector configured to collect radiation in an ultraviolet (UV) spectrum at a powder bed surface within a vacuum chamber during an electron beam scanning cycle of EB-PBF operation, an optical fiber configured to be transparent to the radiation in the UV spectrum and configured to receive the radiation at the powder bed surface via the radiation collector, and a processor configured to receive one or more extracted wavelengths of radiation in the UV spectrum based on the radiation carried on the optical fiber.

Method, product and blocking element of short wavelengths in LED-type light sources consisting of a substrate with a pigment distributed on its surface and, in that said pigment has an optical density such that it allows the selective absorption of short wavelengths between 380 nm and 500 nm in a range between 1 and 99 %.

An ultraviolet ray detecting device is provided. The ultraviolet ray detecting device comprises: a substrate; a buffer layer disposed on the substrate; a light absorption layer disposed on the buffer layer; a capping layer disposed on the light absorption layer; and a Schottky layer disposed on a partial region of the capping layer, wherein the capping layer has an energy bandgap larger than that of the light absorption layer.

A method and a corresponding assembly for detecting corona discharges of a system of equipment includes a sensor assembly that is guided along the system by a vehicle, a first camera for detecting UV radiation is used with a daylight filter for blocking daylight for the sensor assembly, and images of the system are captured by the sensor assembly. The captured images of the camera are provided with a three-dimensional position using an analysis device. Possible corona discharges are detected in each individual image using the analysis device and are transferred into a single three-dimensional space using the respective three-dimensional position. A spatial statistic regarding the frequency of possible current discharges is generated using the analysis device, and the spatial statistic is used to detect actual corona discharges as occurring frequently and at a fixed location in contrast to random noise.

An extreme ultraviolet light sensor unit according to one aspect of the present disclosure includes: a mirror configured to reflect extreme ultraviolet light; a wavelength filter configured to selectively transmit the extreme ultraviolet light reflected by the mirror; an optical sensor configured to detect the extreme ultraviolet light having transmitted through the wavelength filter; and a purge gas supply unit disposed to supply purge gas to a space between the wavelength filter and the optical sensor.

To calculate a regular-discharge probability of an optical sensor, a light detection system includes an optical sensor, an application voltage generating circuit that applies a drive pulse voltage to the optical sensor, a discharge determining portion that detects the optical sensor's discharge, a discharge probability calculating portion that calculates a discharge probability in a first state in which light from an additional light source having a known light quantity is incident on the optical sensor or the additional light source is turned off, and in a second state in which the additional light source's turning-on/turning-off state is different from the first state with a pulse width of the drive pulse voltage the same as the first state, a sensitivity parameter storing portion that stores sensitivity parameters of the optical sensor, and another discharge probability calculating portion that calculates a discharge probability of the optical sensor's regular discharge.