Patent ID: 8507866

Claim:
A dispersive infrared spectrometer comprising: a substrate defining at least one slit, the substrate having a first reflective surface; telecentric flat-field foreoptics configured to direct light rays through the at least one slit; a telecentric flat-field collimator positioned facing the first reflective surface of the substrate and configured to collimate the light rays from the at least one slit to provide collimated light rays; a dispersive element optically coupled to the telecentric flat-field collimator, the telecentric flat-field collimator being positioned between the substrate and the dispersive element, the dispersive element configured to receive and spectrally disperse the collimated light rays to provide dispersed light; a detector housed within a cryogenic dewar; and a flat-field relayed imager positioned between the dispersive element and the detector and configured to receive the dispersed light from the dispersive element and to image the dispersed light onto the detector; wherein the substrate, the telecentric flat-field foreoptics, the dispersive element, the telecentric flat-field collimator and the flat-field relayed imager are located outside the cryogenic dewar and, during operation of the spectrometer, are at ambient temperature.