COMPACT SPECTROGRAPH HAVING A WIDE SPECTRAL BAND INCLUDING A PLURALITY OF DIFFRACTION GRATINGS

摘要

The present invention relates to a spectrograph having diffraction gratings including an input slit (3), suitable for transmitting an input light beam including a plurality of wavelengths; a visible matrix detector (4) including at least N rows of photodetectors, where N is no lower than two; and a plurality of N diffraction gratings, said gratings being concave reflection diffraction gratings. According to the invention, the diffraction gratings (1a, 1b) are placed and positioned such that each grating (1a, 1b) receives a part of the light beam transmitted by the input slit (3), angularly diffracts said part of the input beam according to the wavelength in a spectral domain ([λa1,... λaM], [λbi,... λbM] - - -) and forms a spectrum on the visible matrix detector, said spectrum extending according to a separate row of photodetectors respectively for each diffraction grating (1a, 1b).