发明名称 |
Interference measurement apparatus |
摘要 |
<p>A first beam having high coherence and a second beam having low coherence and having a central wavelength difference from that of the first beam are multiplexed onto the same optical axis. First and second multiplexed beams obtained by beam splitting are emitted at a measurement reflection plane and a reference plane, respectively. The reflected first and second multiplexed beams are multiplexed and interfere with each other. The interference generates a first interference signal that is obtained from the first beams at the interference unit and that relates to information on the distance to the measurement reflection plane and a second interference signal that is obtained from the second beams. The first and second interference signals are used to carry out calculations for determining the position of a measurement origin for the measurement reflection plane.</p> |
申请公布号 |
EP1748276(A1) |
申请公布日期 |
2007.01.31 |
申请号 |
EP20060253842 |
申请日期 |
2006.07.21 |
申请人 |
CANON KABUSHIKI KAISHA |
发明人 |
KADOWAKI, HIDEJIRO;ISHIZUKA, KO;KATO, SHIGEKI |
分类号 |
G01B9/02 |
主分类号 |
G01B9/02 |
代理机构 |
|
代理人 |
|
主权项 |
|
地址 |
|