Patent ID: 7956987

Claim:
A measurement apparatus for measuring optical characteristics of a detection target, the measurement apparatus comprising: a polarization controller which controls polarization of light which is incident on the detection target; a wavefront dividing unit which divides a wavefront of the light from the polarization controller; a polarizing unit which polarizes the light transmitted through the detection target; a detector which detects the light transmitted through at least one of said wavefront dividing unit and said polarizing unit; a processor which calculates the optical characteristics of the detection target based on a detection result of said detector; and a first driving unit which moves said wavefront dividing unit with respect to said detector to position said wavefront dividing unit in or outside an optical path running from the detection target to said detector; a second driving unit which moves said polarizing unit with respect to said detector to position said polarizing unit in or outside the optical path, and a control unit which controls said first driving unit and said second driving unit so that said second driving unit positions said polarizing unit outside the optical path when said first driving unit positions said wavefront dividing unit in the optical path, and that said second driving unit positions said polarizing unit in the optical path when said first driving unit positions said wavefront dividing unit outside the optical path, wherein said processor calculates the optical characteristics of the detection target using a detection result obtained when said wavefront dividing unit is positioned in the optical path and a detection result obtained when said wavefront dividing unit is positioned outside the optical path.