| 摘要 |
<p>A two-stage inteferometer includes a laser light source (1) and a beam splitter (2) having a partially metallised surface (3) which acts as an interference plane for producing two separate light beams (4 and 5). A measuring reflector (6) and a reference reflector (7) are disposed in the paths of the beams (4 and 5), respectively. The beam splitter (2) has on each side of the surface (3) a further beam-splitting, partially metallised surface (8,9), the latter surfaces lying symmetrically of the interference plane (3). A deflecting element, which can comprise a one- part element (13) or multiple elements (11, 12-see Fig. 2 not shown), is disposed at the end of the beam splitter (2) facing the measuring and reference reflectors (6,7). The deflecting element has optically effective reflective surfaces (14, 15) which align the light beams (4,5) so that the latter are mutually parallel, and has a beam exit surface (16) extending at 90 DEG to the interference plane (3). <IMAGE></p> |
