Patent ID: 7291829
Filing Date: 2007-11-06
Classification: G01J,G02B,G02F

Abstract:
1. A light intensity detector comprising: a polarization separating element receiving a first polarized light, said polarization separating element deriving a second polarized light from the first polarized light, the second polarized light having a polarization plane set perpendicular to a polarization plane of the first polarized light; and a photoelectric element receiving the second polarized light; wherein said polarization separating element is a beam splitter, the beam splitter including a polarization film intersecting a datum imaginary plane along an inclined imaginary line, the datum imaginary plane set perpendicular to an optical axis of the first polarized light and intersecting the polarization plane of the first polarized light along a reference imaginary line, the inclined imaginary line shifting from the reference imaginary line around the optical axis of the first polarized light by a predetermined rotation angle.