| 摘要 |
An interferometer (10) employs diffractive optics (30 and 40) for measuring errors in test surfaces (14) that differ from planes and spheres. A beam of light (28) having a planar shape is separated into two portions (32 and 34). One of the diffractive optics (30) can be used to reshape the second portion (34) of a beam of light (28) into a non-planar shape along a path of grazing incidence to the test surface (14), and the other diffractive optic (40) can be used to further reshape the second portion (34) back into a planar shape in common with the first portion (32) of the beam of light (28). The two planar beam portions (32 and 34) are recombined to produce an interference pattern (44) representing the errors in the test surface (14).
|
