Interferometers for measuring coherence length and high-speed switching of laser light
US5647032A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Aug 24, 1995 |
| Grant date | Jul 8, 1997 |
| Priority date | — |
| Expiry date | Aug 24, 2015 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG02B6/2861
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
To measure the coherence length of light, an incident beam (20) is caused to interfere with replicas of itself after having variable delays. Variable delays are generated by passing a beam (40) that is a part of the incident beam (20) around a loop (46). The beam partially leaves the loop (46) at each cycle and partially continues looping. A beam (44) with multiple delays leaving from the loop (46) is caused to interfere with a beam (56) that is another part of the incident beam (20) without delay, to create an output beam (60). The intensity of output beam (60) is affected by multiple delays caused by the loop (46), and depends on the coherence length of the incident beam (20). Therefore, the coherence length of the incident beam (20) can be obtained by detecting the intensity of output beam (60). When the coherence length of light is sufficiently large, by setting the resultant intensity of output beam (60) to be zero, the interferometer can also be used for high speed switching of laser light, based on a transient phenomenon.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.