Patent ID: 9534953
Date: 2017-01-03
CPC Classifications: G01J

Claim:
1. A laser output measuring apparatus comprising: a lens that converges a laser beam incident thereon; an optical separator that reflects a part of the laser beam according to a polarization direction of the laser beam converged by the lens and a Fresnel reflectivity that depends on an incident angle of the laser beam; a photodetector that measures an intensity of the laser beam reflected by the optical separator; a first angle adjusting actuator that rotates the optical separator by a predetermined angle about an optical axis of the laser beam converged by the lens; and a second angle adjusting actuator that rotates the optical separator by a predetermined angle about an axis being a straight line perpendicular to the optical axis of the laser beam and an incident surface of the laser beam, wherein the optical separator is disposed by the first and second angle adjusting actuators such that the reflectivity of the optical separator is averaged with respect to a deviation of the laser beam from the optical axis.