An echelle grating infrared spectrometer comprising:Ī dispersing grating which is cross-oriented with respect to said echelle grating A spectrometer constructed according to the teachings of the present invention will continuously cover the spectrum between one micron and fifteen microns and have a resolution of 0.1 cm. Also disclosed is use of a Schmidt camera for focusing the further ordered radiation from the echelle grating onto a detector array having individual detectors dispersed on a plane which substantially corresponds to a curved focal plane of the Schmidt camera. In a specific embodiment the cross-dispersing grating and echelle grating are in separate enclosed volumes having access to each other through a single intermediate aperture, reflected energy from the cross-dispersing grating being focused so as to pass through the intermediate aperture and then collimated and directed to the echelle grating for further ordering. Means are also disclosed for cooling the cross-dispersing grating, the echelle grating and the detecting means so that background radiation can be minimized. Ordered radiation from the echelle grating is sensed by a detecting means.
Means are disclosed to direct infrared energy to the cross-dispersing grating and then to the echelle grating.
More specifically, a spectrometer is disclosed having a cross-dispersing grating for ordering infrared energy, and an echelle grating for further ordering of the infrared energy. A cooled echelle grating spectrometer for detecting wavelengths between one micron and fifteen microns.