Measuring method and measuring apparatus for coherent crosstalk light
US7208722B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Mar 18, 2005 |
| Grant date | Apr 24, 2007 |
| Priority date | — |
| Expiry date | Oct 15, 2025 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01M11/333
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
An apparatus for measuring coherent crosstalk (CXT) light of the invention generates in a light source section, measurement light which has been modulated to a sawtooth wave shape and applies this to an object of measurement; sends transmission light and CXT light emerging from the object of measurement to a light receiving section via a variable optical attenuator; applies an electrical signal photoelectric-converted in an optical receiver, to a frequency filter, to thereby extract a beat component corresponding to a frequency difference between the transmission light and CXT light; controls the modulation period of the measurement light so that the power of the beat component becomes a local maximum; varies an optical attenuation amount of a variable optical attenuator, while keeping constant the optimized modulation period; and measures with high accuracy the amount of CXT light generated in the object of measurement, based on a rate of variation in the power of the beat component caused at that time.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.