Patent ID: 6721057
Filing Date: 2004-04-13
Classification: G01J,G02B

Abstract:
A spectral resolving system comprising:an entrance slit structure having an entrance slit extending in a first direction for receiving a beam of light having a photon flux within a predetermined spectral pass band; a beam shearing system including: a beam splitter on the surface of a prism that is aligned at an angle to the first direction so that the received beam of light is split into two separate beams; an air gap adjacent the surface of the prism on which the beam splitter is located; a reflective subsystem having a plurality of reflective surfaces defining separate light paths of equal optical path length for the two separate beams, the reflective surfaces arranged such that when the two beams emerge from the beam shearing system they contain more than 50 percent of the photon flux and the chief rays of the two separate beams are substantially parallel to each other; and wherein the angle at which the beam splitter is aligned is less than the critical angle above which total internal reflection of a portion of the beam of light occurs; and an optical system configured to recombine the two separate beams of light emerging from the beam shearing system onto an exit pupil.