An optical keyswitch includes a casing having a movable portion, a shaft movably disposed on the casing, a resilient member accommodated in the casing, and a switch module including a circuit board, an emitter, and a receiver. The emitter emits an optical signal along an optical path to the receiver. When the shaft is at a non-pressed position, the movable portion has a first spatial relation with the optical path, and the receiver receives the optical signal of a first intensity. When the shaft moves, in response to a pressing force, to a pressed position, the shaft compresses the resilient member and pushes the movable portion to move, so the movable portion no longer has the first spatial relation with the optical path, the optical signal received by the receiver has a second intensity different from the first intensity, and the switch module is triggered to generate a triggering signal.

Systems and methods are disclosed for protecting a UV-transmissive window. The system includes a first light source for emitting UV energy. The system also includes a UV transmissive window having a planar dimension and a thickness direction perpendicular to the planar dimension, the window positioned so that UV energy from the UV light source passes through the thickness dimension of the window. The system further includes a second light source for introducing a beam of light transverse to the thickness dimension of the window, a detector for detecting light received from the second light source after the light passes through the thickness dimension, and a control system responsive to changes in the detected light received from the second light source and configured to transmit an alert when a change in the detected light exceeds a threshold.

The invention relates to a method for determining the thickness of a contaminating layer and/or the type of a contaminating material on a surface (7) in an optical system, in particular on a surface (7) in an EUV lithography system, comprising: irradiating the surface (7) on which plasmonic nanoparticles (8a,b) are formed with measurement radiation (10), detecting the measurement radiation (10a) scattered at the plasmonic nanoparticles (8a,b), and determining the thickness of the contaminating layer and/or the type of the contaminating material on the basis of the detected measurement radiation (10a). The invention also relates to an optical element (1) for reflecting EUV radiation (4), and to an EUV lithography system.

An optical safety beam method and system has a transmitter that periodically sends bursts of light pulses with varying strengths. The receiver analyzes the received light pulses to automatically adjust its sensitivity and to detect when the light path is partially obstructed even when there are stray light pulse reflections that reach the receiver.

Eyewear having monitoring capability, such as for radiation or motion, is disclosed. Radiation, such as ultraviolet (UV) radiation, infrared (IR) radiation or light, can be measured by a detector. The measured radiation can then be used in providing radiation-related information to a user of the eyewear. Motion can be measure by a detector, and the measured motion can be used to determine whether the eyewear is being worn.

A system is capable of detecting substrates and can differentiate between zero, one, or multiple transparent or semi-transparent substrates in a stack. The system can include an optical sensor, an optically anti-reflective element, and a detector. The optical sensor outputs light towards the optically anti-reflective element. The light detector is positioned to detect light from the light source that is reflected by substrates, if any, positioned within a detection zone between the optically anti-reflective element and the detector.

Signal processing method for histogram generation, and corresponding device and use. The method generates the histogram from a plurality of event detectors that generate event signals as a response to external events, and are connected to a current injection module which is connected to a plurality of capacitors, wherein each histogram bin is univocally assigned to a capacitor. The method includes: during an event time interval corresponding to a bin, the event detectors generate event signals as a response to external events; the current injection module detects said event signals and, for each event signal, generates a corresponding current signal, which is injected in a capacitor assigned to said bin, and stored therein; repeating steps for each successive bin of said histogram; and reading the charge accumulated in each of said capacitors.

Eyewear having monitoring capability, such as for radiation, is disclosed. Radiation, such as ultraviolet (UV) radiation, infrared (IR) radiation or light, can be measured by a detector. The measured radiation can then be used in providing radiation-related information to a user of the eyewear. Advantageously, the user of the eyewear is able to easily monitor their exposure to radiation.

A biometric sensor for detecting wrist blood vessels in a wristband or wristwatch. The sensor has a substrate and an array of thermal detectors arranged on the substrate. Suitable detectors include near infrared photodetectors or temperature detectors. Advantageously, the array has printed organic components on the substrate.

This disclosure provides systems, methods, and apparatus for controlling transitions in an optically switchable device. In one aspect, a controller for a tintable window may include a processor, an input for receiving output signals from sensors, and instructions for causing the processor to determine a level of tint of the tintable window, and an output for controlling the level of tint in the tintable window. The instructions may include a relationship between the received output signals and the level of tint, with the relationship employing output signals from an exterior photosensor, an interior photosensor, an occupancy sensor, an exterior temperature sensor, and a transmissivity sensor. In some instances, the controller may receive output signals over a network and/or be interfaced with a network, and in some instances, the controller may be a standalone controller that is not interfaced with a network.