| 摘要 |
<p>A grazing incidence interferometer (1) includes a laser (10) and a beamsplitter (16) for splitting an output of the laser into a reference beam (B) and into a sample beam (A). A surface (18) to be examined is disposed at a first angle such that the sample beam is incident on and reflects from the surface at an angle of incidence other than normal, thereby providing a grazing incidence configuration. A beam combiner (22) combines the reference beam and the sample beam that reflects from the surface into a combined beam (C). An image plane (24) is disposed for receiving the combined beam such that an interference pattern is formed at the image plane. The image plane is disposed at a second angle to the combined beam, the second angle being selected to compensate for a reduction in an aspect ratio of the interference pattern that results from the surface being disposed at the first angle. The second angle may be approximately equal to the first angle, or may differ from the first angle to obtain a desired aspect ratio. <IMAGE></p> |
