Wavelength determining apparatus and method
US6992774B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jul 3, 2003 |
| Grant date | Jan 31, 2006 |
| Priority date | — |
| Expiry date | Jun 23, 2024 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01J9/0246
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
An apparatus for determining the wavelength of light emitted by, for example, a laser, includes three photodiodes. One photodiode receives a proportion of the light redirected from the main optical path by a beam splitter. A second photodiode receives a proportion of the light redirected from the main optical path by the beam splitter and passing through a broadband filter. A third photodiode receives light that has been caused to interfere by an interferometric device. The ratio of the light intensities at the first and second photodiodes provide a coarse determination of wavelength, when compared to a lookup table, and the ratio of the light intensities at the first and third photodiodes provide a more exact determination of the wavelength.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.