A thermal radiation light detection device includes: a housing including a plurality of wall portions; a light entrance unit attached to a wall portion and configured to cause thermal radiation light to enter the housing; a light extraction unit disposed inside housing and configured to extract light of a first wavelength and light of a second wavelength from the thermal radiation light, the second wavelength being different from the first wavelength; a first light detection unit attached to a wall portion and configured to detect the light of the first wavelength; a second light detection unit attached to a wall portion and configured to detect the light of the second wavelength; and a first temperature detection unit attached to a wall portion, the wall portion to which the first temperature detection unit is attached being different from the wall portion to which the first light detection unit is attached.

A method and apparatus are provided for generating a thermal image of a target. The method comprises: at one or more electro-magnetic transducers, receiving long wave infra-red (LWIR) radiation emitted from the target; illuminating the electro-magnetic transducers with radiation being transmitted wavelengths that belong to Near Infra-Red (NIR) band and/or that belong to the visible (VIS) band; converting at least part of the radiation received as LWIR radiation to energy at the NIR band and/or at the VIS band; and generating a thermal image based on the energy retrieved after converting at least part of the LWIR radiation received, to energy at the NIR band and/or at the VIS band, and wherein receiving the LWIR radiation and illuminating the electro-magnetic transducers, are carried out simultaneously.

Methods and systems for converting an image contrast evolution of an object to a temperature contrast evolution and vice versa are disclosed, including methods for assessing an emissivity of the object; calculating an afterglow heat flux evolution; calculating a measurement region of interest temperature change; calculating a reference region of interest temperature change; calculating a reflection temperature change; calculating the image contrast evolution or the temperature contrast evolution; and converting the image contrast evolution to the temperature contrast evolution or vice versa, respectively.

Methods and systems for converting an image contrast evolution of an object to a temperature contrast evolution and vice versa are disclosed, including methods for assessing an emissivity of the object; calculating an afterglow heat flux evolution; calculating a measurement region of interest temperature change; calculating a reference region of interest temperature change; calculating a reflection temperature change; calculating the image contrast evolution or the temperature contrast evolution; and converting the image contrast evolution to the temperature contrast evolution or vice versa, respectively.

The present application discloses a light-emitting element comprising a semiconductor light-emitting stack emitting a first light which has a first color coordinate, a first wavelength conversion material on the semiconductor light-emitting stack converting the first light to emit a second light, and a second wavelength conversion material on the first wavelength conversion material converting the second light to emit a third light. The first light and the second light are mixed to be a fourth light having a second color coordinate. The third light and the fourth light are mixed to be a fifth light having a third color coordinate, and the second color coordinate locates at the top right of the first color coordinate and the third color coordinate locates at the top right of the second color coordinate.

According to an embodiment there is provided a distributed optical sensing apparatus for determining of a primary quantity along a waveguide, the distributed optical sensing apparatus comprising: an electromagnetic radiation source adapted for coupling electromagnetic radiation into the waveguide to thereby generate in the waveguide (e.g. by interaction with the waveguide) a first response radiation and a different second response radiation; a detector device adapted for providing a first measurement signal indicative of the first response radiation and a second measurement signal indicative of the second response radiation; an evaluation unit adapted for deriving a secondary quantity (e.g. a loss) based on the first measurement signal and the second measurement signal; the evaluation unit being further adapted for deriving the primary quantity based on the secondary quantity and at least one of the first measurement signal and the second measurement signal.

According to an embodiment there is provided a distributed optical sensing apparatus for determining of a primary quantity along a waveguide, the distributed optical sensing apparatus comprising: an electromagnetic radiation source adapted for coupling electromagnetic radiation into the waveguide to thereby generate in the waveguide (e.g. by interaction with the waveguide) a first response radiation and a different second response radiation; a detector device adapted for providing a first measurement signal indicative of the first response radiation and a second measurement signal indicative of the second response radiation; an evaluation unit adapted for deriving a secondary quantity (e.g. a loss) based on the first measurement signal and the second measurement signal; the evaluation unit being further adapted for deriving the primary quantity based on the secondary quantity and at least one of the first measurement signal and the second measurement signal.

Described herein is a method and a device for monitoring radiation emitted by a radiation emitting element of a thermal radiation source within the visible and the infrared spectral ranges, specifically for determining an emission spectrum of the thermal radiation source. The method includes the following steps: a) providing a thermal radiation source including a radiation emitting element; b) providing at least one radiation sensitive element; c) measuring a spectral radiance of the radiation emitted by the radiation emitting element at at least two individual wavelengths; and d) determining an emission temperature of the radiation emitting element by providing a ratio of the measured values of the spectral radiance of the radiation at the at least two individual wavelengths.

Described herein is a method and a device for monitoring radiation emitted by a radiation emitting element of a thermal radiation source within the visible and the infrared spectral ranges, specifically for determining an emission spectrum of the thermal radiation source. The method includes the following steps: a) providing a thermal radiation source including a radiation emitting element; b) providing at least one radiation sensitive element; c) measuring a spectral radiance of the radiation emitted by the radiation emitting element at at least two individual wavelengths; and d) determining an emission temperature of the radiation emitting element by providing a ratio of the measured values of the spectral radiance of the radiation at the at least two individual wavelengths.

Process for measuring emission for a flame in an open combustion environment. A captured image is received from each of a plurality of image capturing devices in at least one selected spectral band. Each of the plurality of image capturing devices is trained on the flame from the combustion process from a different perspective view angle. A spectral path length of the flame in the at least one spectral band is estimated from the captured images. Emitted radiance of the flame is estimated from the captured images, and a temperature of the flame is estimated from the estimated emitted radiance. A gas species concentration of the flame is estimated from the temperature of the flame and the spectral path length of the flame. Emission for the flame is measured from the gas species concentration.