Patent ID: 6870872
Filing Date: 2005-03-22
Classification: H01S

Abstract:
1. An etalon comprising: an analyzer configured to receive light; a first λ/4 plate, having an optical axis forming a 45 degree angle with respect to an optical axis of the analyzer, and configured to receive light transmitted via the analyzer; a second λ/4 plate, having an optical axis which is parallel to or 90 degrees to the optical axis of the first λ/4 plate, configured to receive light transmitted via the first λ/4 plate; a first reflection surface at a boundary between the first and second λ/4 plates; and a second reflection surface at a surface of the second λ/4 plate on an opposite side of a surface of the second λ/4 plate located at the boundary between the first and second λ/4 plates, wherein a reflection occurs between the first and second reflection surfaces.