Dual beam interferometer with rotary mirror system - has beam splitter(s) for amplitude splitting of incident measuring beam and detectors evaluating partial beams mixed by reflectors

摘要

The rotary mirror system (8) has two plane-parallel reflective surfaces (9,10) and is rotatable about an axis (11) parallel to the latter (9,10) and traverse to the beam path. One partial beam (3) split from the measuring beam (1) by the splitter (2), at least partially, passes through the mirror system. A reflector system (5,6) is provided for each partial beam (3,4). A detector system (D) evaluates the partial beams (3'4') reflected and interference-mixed. The beam splitter (2) is fixed w.r.t. the reflector systems and installed before the mirror system such that at least one partial beam on the way to the reflector fully passes through the mirror system by being reflected from both surfaces (9,10). ADVANTAGE - Simple construction with relatively large optical wavelength change.