Device for the Spectrally Resolved Detection of Optical Radiation

Device for the spectrally resolved detection of optical radiation during a thermal process, comprising an evaluation device, at least one, in a predefined wavelength range light-sensitive element, a reflective diffraction grating and at least one lens for collimation and/or focusing, wherein the at least one lens is arranged in front of the diffraction grating, and wherein the optical radiation is directed through the at least one lens onto the diffraction grating, is spectrally separated from the diffraction grating and is directed back through the at least one lens onto the at least one light-sensitive element,

• characterized in that,
• the device comprises a mirror arranged along the propagation direction of the optical radiation in front of the at least one lens and the diffraction grating, and two light-sensitive elements, each of which is sensitive to a predefined wavelength range that is different from the other light-sensitive element, wherein the mirror is a reflecting beam splitter which converts the incident optical radiation into two partial beams which are spectrally separated from the diffraction grating and are directed back through the at least one lens onto in each case one of the light-sensitive elements.