High channel density, broad bandwidth wavelength division multiplexer with highly non-uniform Bragg-Littrow holographic grating
US5026131A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Nov 13, 1989 |
| Grant date | Jun 25, 1991 |
| Priority date | — |
| Expiry date | Nov 13, 2009 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG02B6/2938
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
A wavelength division multiplexer/demultiplexer having optical path lengths between a fiber array and a Fourier transform lens, and between a dispersion grating and the lens equal to the focal length of the lens. The equal optical path lengths reduce losses due to angular acceptance mismatch in the multiplexer. Close orientation of the fiber array about the optical axis and the use of a holographic dispersion grating reduces other losses in the system. Multi-exposure holographic dispersion gratings enable the multiplexer/demultiplexer for extremely broad-band simultaneous transmission and reflection operation. Individual Bragg plane sets recorded in the grating are dedicated to and operate efficiently on discrete wavelength ranges. A volume Bragg vertically non-uniform holographic grating enables operation of the multiplexer or other devices that act on light waves according to wavelength over nearly the full usable 0.8-1.3 .mu.m wavelength range.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.