Monitoring and controlling source stability
US4817100A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Sep 11, 1987 |
| Grant date | Mar 28, 1989 |
| Priority date | — |
| Expiry date | Sep 11, 2007 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01S5/0687
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
A method and apparatus for monitoring and/or controlling the frequency of a beam of coherent radiation. The apparatus comprises a reference source (1) which is controlled to generate reference radiation beam with a frequency which is repeatedly swept through a range of operating frequencies. This reference beam is combined with a beam of coherent radiation from a test source and the combined beams are fed to a photodiode (9). The output of the photodiode (9) can be displayed so that the upper and lower beat frequencies can be determined enabling the variation of the average of the upper and lower beat frequencies with time to be monitored. Alternatively, the average beat frequency can be fed back as a control signal to control the test beam source (8). In this latter case, the frequency of the test beam will be locked.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.