Polarization-independent reflectometry and polarization-independent reflectometer
US6476919B1 · kind B1 · utility
Assignees
Inventors
Key dates
| Filing date | Sep 24, 1999 |
| Grant date | Nov 5, 2002 |
| Priority date | — |
| Expiry date | Sep 24, 2019 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01M11/3181
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
Emitted light from a light source 1 is separated into two parts through an optical fiber coupler 2, one is entered in a measured optical module 3 as measurement light, and the other is given a group delay by means of an optical fiber delay line 5, a reflector 25, etc., as local light signal, then the local light signal is combined with reflected light signal from the measured optical module 3 through an optical fiber coupler 21 and the reflected light signal and the local light signal are caused to interfere with each other. A polarization controller 100 comprising a polarizer and a polarization rotation device for arbitrarily rotating the polarization state 0 degrees and 90 degrees at the time is used to generate beat signals at the polarization rotation angles, and the sum of the intensities of the beat signals is found, making it possible to measure the light power of the reflected light signal regardless of the polarization state of the local light signal or reflected light signal.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.