Fourier transform spectroscopy by varying the path length difference between the paths in each of a plurality of pairs of optical paths
US5422721A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Apr 11, 1994 |
| Grant date | Jun 6, 1995 |
| Priority date | — |
| Expiry date | Apr 11, 2014 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01J3/4535
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A Fourier-transform spectrometer includes a plurality of detectors (118-1 through 118-L), each of which receives light from a pair of optical paths of different optical path lengths. A movable mirror (116) varies the difference between the path lengths of each pair. Analog-to-digital converters (124-1 through 124-L) sample the resultant outputs at regular distance-difference intervals so as to generate sequences of sample values. The distance-difference ranges for the pairs of paths associated with different detectors are different, and the sequences together make up a synthetic interferogram that covers a range of distance differences 2L times the range of motion of the movable mirror (116). A Fourier transformation circuit (126) computes the Fourier transform of the synthetic interferogram, thereby determining the power spectrum of the incoming light, and operates a display (128) to indicate the result.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.