Measuring apparatus and a measuring method for measuring a polarization characteristic of an optical system

A measuring apparatus configured to measure a polarization characteristic and a transmission wavefront of a test object, the measuring apparatus comprising:

• a beam splitter configured to split light from a light source into reference light and light under test;
• a light shielding member;
• and a spherical mirror which reflects the light under test which has passed the test object and directs the light under test again to the test object;
• and a detector configured to detect the light under test, wherein said detector also detects the reference light when said light shielding member does not shield the reference light, wherein the transmission wavefront of the test object is measured when the detector detects an interference pattern formed by interference between the light under test and the reference light, wherein a polarization characteristic matrix in a pupil plane of the test object is measured when a light shielding member shields the reference light and the detector detects only the light under test:
• wherein the light shielding member includes a spatial filter which is disposed on a plane where the reference light is converged, and wherein the reference light is blocked by the spatial filter when the spherical mirror and the spatial filter are moved.