Absolute optical frequency calibrator for a variable frequency optical source
US5780843A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jul 16, 1996 |
| Grant date | Jul 14, 1998 |
| Priority date | — |
| Expiry date | Jul 16, 2016 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01J2003/2866
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
Calibration of a variable frequency light source is performed by a control unit which has a knowledge of the known transmission pattern of an optical filter, such as gas cell or a calibrated interferometer, having a number of known frequency dependent transmission characteristics in the tuning range of the optical source. This unit scans the frequency of the optical source via a frequency control signal over a frequency range and measures the optical intensity of the optical source output light after it has passed through the optical filter The measured transmission and frequency control signal values are processed and stored in memory and constitute a measured absorption pattern. Once acquired for a frequency range, this pattern is compared to the theoretical transmission pattern of the optical filter. Correspondences are made to identify the transmission features against their known counterparts. A relationship between the frequency control signal and actual frequency of the optical source is established. The frequency calibration of the optical source over many frequency points is achieved. The invention is especially suited to the frequency calibration of tunable laser sources,…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.