Patent ID: 7256890

Claim:
A spectroscope comprising: an input portion; a spectroscopic element that disperses light come out from the input portion; an exit portion that exits the light dispersed by the spectroscopic element, or a detector that detects the light dispersed by the spectroscopic element; a polarization dividing element that divides the light from the input portion into a first optical path and a second optical path and gives each light of each optical path different direction of polarization with each other; a polarization rotator that is disposed in the first optical path and arranges the direction of polarization of the light in the first optical path into the direction of polarization of the light in the second optical path; and a beam deflector that is disposed in either one optical path of the first optical path and the second optical path and deflects the one optical path such that at least a portion of an area where the light proceeding through the one optical path is incident on the spectroscopic element and an area where the light proceeding through the other optical path is incident on the spectroscopic element overlap each other.