A photoionization detector (100) comprises an ultraviolet radiation source (130); one or more detector electrodes (204 and 205); and a shielding material (206) located between the ultraviolet radiation source (130) and the one or more detector electrodes (204 and 205), wherein the ultraviolet radiation (240) does not directly impinge on any part of the one or more detector electrodes (204 and 205). A method for gas detection comprises exposing a photoionization detector (100) to an environment containing a target gas; and shielding the one or more detector electrodes (204 and 205) from direct impingement from the ultraviolet radiation (240) via the shielding material (206).

An imaging system includes: an image sensor sensitive to ultraviolet light and visible light; a lens configured to focus light from a subject onto the image sensor; and an image processor configured to process image signals output from the image sensor. The image processor obtains the difference between image signals A1 and A2 output from the image sensor at times t1 and t2, respectively. If the differential signal A3 is greater than or equal to a predetermined value, the image processor determines that light from the subject contains the ultraviolet light, and generates an image signal CI based on the differential signal A3.

The exemplified systems, and method thereof, includes PLZT thin film (Pb.sub.0.95La.sub.0.05Zr.sub.0.54Ti.sub.0.46O.sub.3) paired with a bottom metal and top transparent conductive oxide, that forms a capacitor structure with enhanced photocurrent and power conversion efficiency. The exemplified systems use metal electrode (platinum) as bottom electrode and a transparent oxide (Indium Tin OxideITO) as the top electrode. In some embodiments, the capacitor structure are used in a solar cells, ultraviolet sensors, or UV indexing sensors. In some embodiments, the capacitor structure are energy generation or for medical diagnostics (e.g., for skin care application).

A flame detection system includes a determiner and an outputter. The determiner is configured to, when image processing performed on image data detects ultraviolet light, determine that a light emitting source is a fire flame. The outputter is configured to output a determination result by the determiner.

Apparatus for measuring a dosage of disinfection light. The apparatus includes: a measurement pad including a photochromic material that changes its color in response to a dosage of disinfection light incident on the measurement pad; and a dosage scale bar having a plurality of units that have different colors, wherein the dosage of the disinfection light is determined by comparing the color of the measurement pad with the different colors of the plurality of units.

According to one embodiment, a superconducting element used as a pixel for detecting a particle is disclosed. The superconducting element includes at least one superconducting strip. The at least one superconducting strip includes a meandering structure. The meandering structure includes a first portion extending in a first direction and made of a superconducting material, a second portion connected to the first portion, extending in a second direction perpendicular to the first direction, and being conductive, and a third portion connected to the second portion, extending in a direction opposite to the first direction, and made of a superconducting material. A superconducting region of any one of the first portion and the third portion is configured to be divided when the particle is radiated to the first portion.

This disclosure is directed to devices, systems, and methods for skin damage protection and detection, including providing images and recommendations and images to users to assist them with proper application of an applied-to-skin sunscreen. Disclosed devices include personal user devices that are operable to emit ultraviolet light and to measure the degree of ultraviolet light reflected from skin, upon which images can be presented on a device screen to give visual indications of sunscreen coverage and/or skin aging. Measured ultraviolet images and visible light images can further be presented to device users in an overlay, side-by-side, or other fashion, to further assist in detection of sunscreen coverage and/or degrees of skin damage. Further, the user of the device may be able to view real-time video in the same ultraviolet/visible light overlay fashion, and assess the state of photo-protective effects of an applied-to-skin sunscreen.

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.

The present disclosure provides a fluorescent nitrogen-vacancy diamond (FNVD) having a plurality of nitrogen-vacancy centers with a concentration about 1 ppm to 10,000 ppm. The FNVD as built-in fluorophores exhibit a nearly constant emission profile over 540 nm to 850 nm upon excitation by vacuum ultraviolet (VUV), extreme ultraviolet (EUV) and X-rays for the energy larger than 6.2 eV. Applying the FNVD sensor can measure VUV/EUV/X-rays as a sensing sheet, manufacturing method and uses thereof, sensor and lithography apparatus. The superb photostability and broad applicability of FNVDs offer a promising solution for the long-standing problem of lacking robust and reliable detectors for VUV, EUV, and X-rays.

A down-converted light emitting combination that generates a visible light when an ultraviolet light is incident is provided. The down-converted light emitting combination includes a first structure made of a first material that generates a visible light of a first color when an ultraviolet light of a first wavelength range is incident and a second structure made of a second material that generates a visible light of a second color different from the first color when the ultraviolet light of a second wavelength range different from the first wavelength range is incident, and the first material and the second material have different emission colors and distributions of intensities of the visible lights generated depending on a wavelength of the incident ultraviolet light.