Polarizing interferometer using multiorder and zero order birefringence switches
US6100944A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Oct 10, 1997 |
| Grant date | Aug 8, 2000 |
| Priority date | — |
| Expiry date | Oct 10, 2017 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG02F1/21
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
The present invention provides a polarizing interferometer multiplex spectrometer using a zero-order switch, a multi-order switch and an output polarizer to multiplex the recovery of an entire input spectrum. The zero-order switch and multi-order switch require input light of a fixed polarization; thus the present invention provides a preferred embodiment that uses a zero-order switch and a multi-order switch positioned between an input polarizer and an output polarizer. For a sequence of time delays incremented by the multi-order and zero-order switches, the total transmitted power at all wavelengths is measured. From these, the coefficients of a Fourier series representation of the input spectrum are obtained, and the entire spectrum is mathematically reconstructed. Although the structure is similar to a tunable interference filter, the PIMS does not function as a filter, and more particularly, does not scan the transmission wavelength and measure power as a function of wavelength. The present invention further provides a multi-order switch that uses an active LC device to switch between summing and differencing the retardances of two fixed retarders. The present invention furthe…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.