| 摘要 |
An interferometer for length measurement, which operates using a high-intensity IR laser diode, contains a small beam splitter and a 90 DEG deflecting prism connected thereto by means of which an incident laser beam is coupled onto two parallel planes. One plane contains a measuring interferometer, and the other plane, which is located therebelow or thereabove, a control interferometer. The first of these contains a beam splitter in which an incident laser beam polarised by 45 DEG is split into a reference beam and a measuring beam at right angles thereto, as well as a 90 DEG prism or triple prism in which the two beams are reflected displaced in parallel, whereupon they are reunited in the beam splitter and then split into two signals phase-shifted by 180 DEG . Arranged to follow is a polarising beam splitter through which one portion of the signals is guided directly and the other portion is guided via a 90 DEG prism, four signals with a phase shift advancing by 90 DEG in each case being produced by splitting into a horizontal and a vertical component, respectively. The control interferometer likewise contains a beam splitter, in which the same laser beam is split into a reference beam and a measuring beam at right angles thereto, as well as a 90 DEG prism or two prisms in which the two beams are reflected displaced in parallel, whereupon they are reunited in the beam splitter and then ... Original abstract incomplete.
|
