| 摘要 |
A full-field, geometrically-desensitized interferometer (GDI) instrument incorporates a combination of reflecting and refracting optics to perform beam splitting and recombining operations for surface profilometry. Symmetrically-positioned inbound and outbound optical subassemblies typically are arranged to direct inbound collimated beams from a light generator to the profiled surface of a test object and to direct outbound reflected beams to an imaging device as a single recombined outbound interference beam. Every point on the detector has a corresponding point on the object from which reflected illumination originated from both reflected beams. The optical path difference between the two inbound beams or between the two reflected outbound beams can be substantially independent of field position. The resultant instrument, in addition to being capable of full-field imaging, exhibits several advantages including 1) a large working distance, 2) the employment of readily-available non-diffractive elements, and 3) the ability to transmit light with high efficiency.
|
