Interferometer control and laser frequency locking
US6801324B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | May 29, 2002 |
| Grant date | Oct 5, 2004 |
| Priority date | — |
| Expiry date | Jul 28, 2022 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01S7/4911
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
This invention provides a method and an optical system for sensing and controlling the frequency for a laser with respect to an optical cavity and for sensing and controlling the length difference of interferometer paths in a two beam interferometer. A misalignment is introduced in the incident laser radiation to produce a fundamental mode (TEM00) in the cavity or interferometer and the reflection of a least one higher order mode (TEM01). A split photodetector (10) allows the interference between these two modes to be measured separately by detecting two spatially distinct portions of the single reflected beam. An error signal indicative of the difference between the fundamental mode frequency and the cavity resonant frequency is obtained by substracting the outputs from the two parts of the photodetector.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.