Patent ID: 6980303

Claim:
A light emitting/receiving composite unit, comprising: a light source for emitting a light; an optical splitting unit for splitting returning lights into a plurality of lights, the light from the light source going to and returning from an external optical system to be the returning lights; a polarizing unit for increasing and decreasing quantity of lights transmitted therefrom corresponding to polarization state of the returning lights; and an optical receiving unit which has a plurality of photo-detecting elements for detecting the lights transmitted through the polarizing unit; wherein the light source, the optical splitting unit, the polarizing unit, and the optical receiving unit are unitedly integrated into one unit, wherein the light source has a light emitting element, and an optical path deflecting means for deflecting the light emitted from the light emitting element along a set up optical axis of the light source, and when viewing from the direction of the optical axes of the light source and the optical receiving unit, a straight line including the light emission direction of the light emitting element and a straight line connecting the respective centers of the photo-detecting elements arranged in the optical receiving unit form a predetermined angle.