Optical waveguide based surface profiling apparatus
US7221814B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jul 23, 2003 |
| Grant date | May 22, 2007 |
| Priority date | — |
| Expiry date | Jul 23, 2023 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG02B6/29356
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
Surface profiling apparatus (10) according to one embodiment comprises three long period gratings (LPGs) (12, 14, 16) fabricated in progressive three layered (PTL) fibre (18) and embedded within a deformable carrier member (40) comprising a skeleton (42) provided between two sheets of flexible rubber skin (44, 46). The LPGs (12, 14, 16) are illuminated by three wavelength modulated, narrow bandwidth optical signals, each having a different wavelength and modulation frequency. A photodetector (26) connected to three lock-in amplifiers (28, 30, 32) measures the amplitudes of the first and second harmonic frequency components of the photodetector output signal corresponding to each LPG (12, 14, 16). Similar surface profiling apparatus (10) forms the basis for respiratory function monitoring apparatus (100) in which five LPGs are provided within each of four PTL fibres (104, 106, 108, 110) and embedded in four carrier members (40a–d) attached to a garment (114) to be worn by a subject.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.