Long period chiral fiber grating apparatus
US6925230B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Mar 21, 2003 |
| Grant date | Aug 2, 2005 |
| Priority date | — |
| Expiry date | Mar 21, 2023 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG02B2006/0209
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
A long period chiral fiber grating (“LPCFG”) that has a number of advantageous properties that can be readily utilized in a number of different applications is provided. The inventive LPCFG is a fiber grating having a pitch that exceeds the wavelength of light propagating therethrough. The LPCFG includes a number of dips in its transmission spectrum, but does not reflect any portion of the signal passing therethrough. The LPCFG is sensitive to changes in the refractive index of its external environment (or in the refractive index of a coating covering the LPCFG cladding). In response to changes in the external refractive index, the transmission dips shift proportionally to changes in the index, thus enabling the use of LPCFG as a fiber sensor element. In addition, the LPCFG is polarization sensitive—one circular polarized wave of one handedness is coupled to the cladding mode stronger than the wave of the other polarization handedness. This enables the LPCFG to be readily utilized in polarizers and for shaping the polarization spectra of signals passing therethrough (in one embodiment configured as multiple LPCFG elements having different pitches). The polarization sensitivity of t…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.