A ultraviolet (UV) intensity indicator might use a UV responsive lumiphore to provide a converted, visible light level proportional to received UV light intensity for comparison to a visible brightness reference. For a desired UV intensity, the converted light should normally appear at least as bright as the reference light. For undesired UV, e.g. in a harmful wavelength range, the converted light should appear dimmer than the reference for normal operation and/or appear as bright as or brighter than the reference during excessive emission of the potentially hazardous UV emission. Alternatively, saturable lumiphores may provide different color outputs responsive to UV intensities for comparison to a multi-colored reference. Other examples contemplate use of a lumiphore to convert UV light to provide a visible light input to a visible light meter, such that an illuminance or brightness measurement by the meter gives a proportional representation of intensity of the UV light.

A ultraviolet (UV) intensity indicator might use a UV responsive lumiphore to provide a converted, visible light level proportional to received UV light intensity for comparison to a visible brightness reference. For a desired UV intensity, the converted light should normally appear at least as bright as the reference light. For undesired UV, e.g. in a harmful wavelength range, the converted light should appear dimmer than the reference for normal operation and/or appear as bright as or brighter than the reference during excessive emission of the potentially hazardous UV emission. Alternatively, saturable lumiphores may provide different color outputs responsive to UV intensities for comparison to a multi-colored reference. Other examples contemplate use of a lumiphore to convert UV light to provide a visible light input to a visible light meter, such that an illuminance or brightness measurement by the meter gives a proportional representation of intensity of the UV light.

A ultraviolet (UV) intensity indicator might use a UV responsive lumiphore to provide a converted, visible light level proportional to received UV light intensity for comparison to a visible brightness reference. For a desired UV intensity, the converted light should normally appear at least as bright as the reference light. For undesired UV, e.g. in a harmful wavelength range, the converted light should appear dimmer than the reference for normal operation and/or appear as bright as or brighter than the reference during excessive emission of the potentially hazardous UV emission. Alternatively, saturable lumiphores may provide different color outputs responsive to UV intensities for comparison to a multi-colored reference. Other examples contemplate use of a lumiphore to convert UV light to provide a visible light input to a visible light meter, such that an illuminance or brightness measurement by the meter gives a proportional representation of intensity of the UV light.

A fluorescence imaging system for imaging an object, the system includes a white light provider that emits white light, an excitation light provider that emits excitation light in a plurality of excitation wavebands for causing the object to emit fluorescent light, a component that directs the white light and excitation light to the object and collects reflected white light and emitted fluorescent light from the object, a filter that blocks light in the excitation wavebands and transmits at least a portion of the reflected white light and fluorescent light, and an image sensor assembly that receives the transmitted reflected white light and the fluorescent light.

A fluorescence imaging system for imaging an object, the system includes a white light provider that emits white light, an excitation light provider that emits excitation light in a plurality of excitation wavebands for causing the object to emit fluorescent light, a component that directs the white light and excitation light to the object and collects reflected white light and emitted fluorescent light from the object, a filter that blocks light in the excitation wavebands and transmits at least a portion of the reflected white light and fluorescent light, and an image sensor assembly that receives the transmitted reflected white light and the fluorescent light.

A sensor device for determining a position of seeds while sowing. The sensor device includes a radiation assembly which generates an illumination radiation oriented towards a target area, and a detection assembly. The radiation assembly includes a radiation source which provides an emission spectrum of the illumination radiation covering a spectral range. The detection assembly includes a radiation detector which detects an incident radiation, and a filter member with an attenuation band and a pass band. The radiation detector includes a field of view. The pass band has an attenuation which is less than an attenuation of the attenuation band in a wavelength range where the wavelengths are longer than those of the attenuation band. The target area and the field of view intersect. The radiation source and the radiation detector form a triangulation arrangement so that a distance from the target area to the detection assembly can be determined.

A sensor device for determining a position of seeds while sowing. The sensor device includes a radiation assembly which generates an illumination radiation oriented towards a target area, and a detection assembly. The radiation assembly includes a radiation source which provides an emission spectrum of the illumination radiation covering a spectral range. The detection assembly includes a radiation detector which detects an incident radiation, and a filter member with an attenuation band and a pass band. The radiation detector includes a field of view. The pass band has an attenuation which is less than an attenuation of the attenuation band in a wavelength range where the wavelengths are longer than those of the attenuation band. The target area and the field of view intersect. The radiation source and the radiation detector form a triangulation arrangement so that a distance from the target area to the detection assembly can be determined.

Apparatuses and methods as described herein can be used to help stabilize the gain of a semiconductor-based photomultiplier. In an embodiment, an apparatus can include a semiconductor-based photomultiplier. The apparatus can be configured to inject a first input pulse into the semiconductor-based photomultiplier; determine a revised bias voltage for the semiconductor-based photomultiplier based at least in part on a first output pulse corresponding to the first input pulse and a second output pulse from the semiconductor-based photomultiplier that is obtained at another time as compared to the first output pulse; and adjust a bias voltage for the semiconductor-based photomultiplier to the revised bias voltage. A calibration light source, a temperature sensor, and temperature information are not required to be used for the method.

A screening system includes a modulated light source, a wavelength-shifting filter, and a photosensor. The light source is operable to emit light into a screening region through which people or objects move. The photosensor is adjacent the screening region and is operable to emit sensor signals from scattered light received through the wavelength-shifting filter from interaction of the light with the people or objects in the screening region.

A laser beam profile measurement device includes: a plate-like or block-like fluorescence generation element including an incidence surface on which a laser light is incident and an emission surface from which the laser light is emitted; a light separation element for separating fluorescence from the laser light, the fluorescence generated in the fluorescence generation element and emitted from the emission surface; and an image element for receiving the fluorescence. The fluorescence generation element includes a first film formed on the incidence surface thereof. The first film has a wavelength-to-reflectance characteristic of transmitting a wavelength λ1 of the laser light and reflecting a wavelength λ2 of the fluorescence. The first film has a wavelength-to-reflectance characteristic of transmitting a wavelength λ1 of the laser light and reflecting a wavelength λ2 of the fluorescence. The light separation element may include a second film having a wavelength-to-reflectance characteristic of transmitting the wavelength λ2 and reflecting the wavelength λ1 or a third film having a wavelength-to-reflectance characteristic of reflecting the wavelength λ2 and transmitting the wavelength λ1. The first film may further have a wavelength-to-reflectance characteristic of reflecting a wavelength λ0 between the wavelength λ1 and the wavelength λ2, while the second film may further have a wavelength-to-reflectance characteristic of reflecting the wavelength λ0. Alternatively, the first film may further have the wavelength-to-reflectance characteristic of reflecting the wavelength λ0 between the wavelength λ1 and the wavelength λ2, while the third film may further have a wavelength-to-reflectance characteristic of transmitting the wavelength λ0.