Patent ID: 7688424
Filing Date: 2010-03-30
Classification: G03B,G03F

Abstract:
1. A measurement apparatus which measures optical characteristics of an optical system to be measured, comprising: a first polarization control unit configured to control a polarization state of light which enters the optical system to be measured to at least two different polarization states; an image sensor configured to measure light transmitted through the optical system to be measured; a wavefront splitting unit which is inserted between said first polarization control unit and the optical system to be measured or between the optical system to be measured and said image sensor, and is configured to split a wavefront of the light; a second polarization control unit which is inserted between the optical system to be measured and said image sensor, includes a phase plate which is rotatable about an optical axis, and is configured to control the polarization state of the light; and a processing unit configured to calculate a non-polarization aberration and a polarization aberration of the optical system to be measured, based on a plurality of interference patterns sequentially sensed by said image sensor by rotating the phase plate, wherein said wavefront splitting unit can be inserted into or removed from an optical path, wherein said processing unit calculates reference birefringence information based on a light intensity sensed by the image sensor when said wavefront splitting unit is not arranged in the optical path, and wherein said processing unit calculates the non-polarization aberration and the polarization aberration of the optical system to be measured, based on the reference birefringence information and interference patterns sensed by said image sensor when said wavefront splitting unit is arranged in the optical path.