| 摘要 |
PROBLEM TO BE SOLVED: To readily perform a precise length measurement in a production site, a research department or the like, in various industrial and technical fields. SOLUTION: A first interferometer 2, which constitutes a tandem interferometer 1, is installed inside a standard chamber 3, a second interferometer 4 is arranged at a site 5 at a factory or in a laboratory, and both are connected by an optical fiber 6. As a light source installed inside the standard chamber 3, a low-coherence light source 10 is used. As a reference material in the first interferometer 2 inside the standard chamber 3, a step difference gage or the like is used. If its step is used as a reference length standard L, its length information is input to the second interferometer 4 at the site 5 via the optical fiber 6, so as to be transferred to a specimen 9. When a length L' is detected, on the basis of an output from the second interferometer 4 in such a way that a measured value L-L' becomes zero, the reference length in the standard chamber can be transmitted to the site as it is, without bringing the reference length into the site. |
