Patent ID: 6560003
Filing Date: 2003-05-06
Classification: G01J,G02B

Abstract:
A light receiving module with reduced polarization dependence comprising:a first lens; a second lens; a first light transmission plate disposed between the first lens and the second lens; a second light transmission plate disposed between the first lens and the first light transmission plate; and a light receiving element having a light receiving surface, the light receiving element disposed adjacent to the first light transmission plate with the second lens sandwiched; wherein the light receiving element is disposed so that the light receiving surface is not perpendicular to an optical axis of an incident light beam; the first optical transmission plate is disposed so that a polarization dependence of the first optical transmission plate is equal to a polarization dependence of the light receiving surface, and the first optical transmission plate is rotated by 90Â° with respect to the optical axis; and the second optical transmission plate is disposed so that the sum of a polarization dependence of the second optical transmission plate and the polarization dependence of the first transmission plate is equal to the polarization dependence of the light receiving surface to cancel out the remaining polarization dependence, and the second optical transmission plate is rotated by 90Â° with respect to the optical axis.