Device for measuring of optical wavelengths
US6680472B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Mar 12, 2002 |
| Grant date | Jan 20, 2004 |
| Priority date | — |
| Expiry date | Mar 12, 2022 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01J9/00
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
Fibre optic apparatus for accurate and repeatable measurements of light comprising one or more wavelength ranges, and system employing the apparatus. The apparatus according to the invention comprises: a directional coupler adapted to lead the light into an optical fibre, said optical fibre containing at least one analysis filter for each wavelength range, said analysis filters consisting of at least one fibre-optical Bragg-grating (FBG) which reflects incident light with a chosen wavelength back through said directional coupler and onto a detector having an associated signal processing unit, a modulator device for pulsing the incident light with a chosen pulse width, and an optical fibre delay line in front of each analysis filter, with a length adapted to provide for a sufficient time delay larger than the pulse width, so that the pulses reflected from each analysis filter at different wavelengths can be separated in time and thereby be demodulated in the signal processing unit.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.