Patent ID: 6552785
Filing Date: 2003-04-22
Classification: G01J

Abstract:
A reference wavelength light generating apparatus comprising:a light source for generating light having a predetermined wavelength range; an absorbing member for absorbing a predetermined wavelength component from incident light; a reflecting member for reflecting any light emitted from said absorbing member in a direction of said absorbing member; light branching unit for branching and emitting the light emitted from said light source in both a direction of said absorbing member and a direction different from that of said absorbing member and also branching and emitting the light incident from said absorbing member in both a direction of said light source and a direction different from that of said light source; and a collimator for converting the light emitted from said light branching unit to said absorbing member side via an optical fiber into parallel rays at an end of said optical fiber and letting said parallel rays into said absorbing member, wherein the light branched from said light branching unit in a direction different from that of said light source is emitted as reference wavelength light and the light branched from said light branching unit in a direction different from said absorbing member is emitted as a measuring beam.