摘要 |
<p>An interferometer comprises a non-uniform beam splitter (34) which splits an incoming beam (30) of energy into two beams (36, 38). The two beams (36, 38) are taken from parts of the incoming beam (30) which overlap. The two beams (36, 38) are fed spacially separated energy feeds (44, 46) and then fed to a comparator to produce sum and difference channels (54, 58). The sum and difference channels (54, 58) are guided to a means for detecting a difference in phase (60) between the sum and difference channels (54, 58).</p> |