Optical power meter with automatic switching of photodetectors having different wavelength sensitivity characteristics
US4749275A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Sep 30, 1986 |
| Grant date | Jun 7, 1988 |
| Priority date | — |
| Expiry date | Sep 30, 2006 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01J1/0488
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
An optical power meter system comprises a chopper with a semicircular total reflection mirror along an incident light path, two photo-detectors of different characteristics of wavelength sensitivity, and a comparator for comparing the levels of the photo-detection signals derived from the two photo-detectors and for outputting the optical detection signal of a higher level. The photo-detectors are positioned in a first path of the light passing through the chopper and a second path of the light reflected by the chopper, respectively. The comparator may be replaced by an adder for adding the photo-detection signals derived from the two photo-detectors.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.