A detecting device for indicating the intensity of a predetermined type of radiation present in electromagnetic radiation incident on the detecting device can include: a filter element for filtering the incident electromagnetic radiation, wherein the filter element is configured to filter off electromagnetic radiation with a wavelength of above 590 nm from the incident electromagnetic radiation; a converging element configured to increase the density of photons of the predetermined type of radiation present in the incident electromagnetic radiation; and a sensor element of material arranged to receive the incident electromagnetic radiation that has passed through the filter element and the converging element for indicating the intensity of the predetermined type of radiation present in the incident electromagnetic radiation by change of the color of the sensor element of material, wherein the material is represented by the following formula: (M)8(MM)6O24(X,S)2:M (formula (I)).

Systems, devices and methods for calibrating or increasing the accuracy of light sensing devices. The methods can include calibrating a light sensing device with a calibration source that is adapted to mimic at least one representative spectrum.

Stray and air scattered light can be reduced by configuring a size of the collection area of a sensor, which reduces a source of sensitivity-limiting noise in the system. By adjusting a size of the collection area, stray deep ultraviolet light and air-scattered deep ultraviolet light can be reduced. A servo can control a position of an illumination spot that is collected by the time delay and integration sensor.

A controller unit for controlling an ultraviolet (UV) sensor may be excited by an excitation voltage that enables the UV sensor to detect incoming UV light. The UV sensor may provide UV detection events that may be related to the intensity of the incoming UV light. The control unit may include an excitation voltage generator, an event detector, and a controller configured to cause the excitation voltage generator to produce an excitation voltage for a cumulative excitation time that is less than 50% of the time, which may significantly increase the operational lifetime and/or reliability of a UV sensor.

An optical detector device includes a housing with a projecting neck that is closed off towards the outside by a light-transmissive pane, under which at least one optical waveguide that tapers in the direction of an optical sensor is disposed. An optical waveguide arrangement has a plurality of optical waveguides which are retained in the neck by a holding mechanism.

System and methods for accurate measurement and real-time feedback of solar ultraviolet exposure for management of ultraviolet dose. The systems can include a wearable device and a mobile device, the system performing accurate measurement of UV exposure.

Radiation detectors based on high electron mobility transistors (HEMTs) are provided. Methods for detecting ultraviolet radiation using the HEMTs are also provided. The transistors are constructed from an intrinsic high bandgap semiconductor material with a built-in polarization field sandwiched between graphene and a two-dimensional electron gas (2DEG).

One variation of a method for measuring ambient ultraviolet light radiation including: calculating a target direct orientation of a light exposure device based on a location, a current date and time, and a direct solar position model; calculating a target diffuse orientation of the light exposure device based on the location, the current date and time, and a diffuse solar position model; in response to detecting alignment between orientation of the light exposure device and the target direct orientation, recording a direct ultraviolet value; in response to detecting alignment between orientation of the light exposure device and the target diffuse orientation, recording a diffuse ultraviolet value; in response to detecting alignment between orientation of the light exposure device and a target global orientation, recording a global ultraviolet value; and calculating an ultraviolet index based on the global ultraviolet value, the direct ultraviolet value, and the diffuse ultraviolet value.

Described herein are systems and methods for coupling environmental hazard detection and actuation of a wearable chemical sensor at a molecular level. The chemical sensor may be a wearable chemical sensor implemented as a powder, cream, lacquer or other wearable construct. The wearable chemical sensor may detect exposure to various environmental hazards and provide an analog means (e.g., a range of color changes) of indicating the level of environmental hazard exposure.

In accordance with at least one aspect of this disclosure, an ultraviolet radiation (UV) sensor includes a UV sensitive material and a first electrode and a second electrode connected in series through the UV sensitive material such that UV radiation can reach the UV sensitive material. The UV sensitive material can include at least one of zinc tin oxide, magnesium oxide, magnesium zinc oxide, or zinc oxide. The electrodes can be interdigitated comb electrodes.