Displacement detection apparatus
US9810521B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jan 27, 2016 |
| Grant date | Nov 7, 2017 |
| Priority date | — |
| Expiry date | Jan 27, 2036 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01D5/38
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A displacement detection apparatus capable of stably and accurately detecting the amount of displacement. The length of a polarization maintaining fiber for transmitting the light from a light source to a displacement detector is set not to be equal to a length obtained by dividing, by the wavelength of the light source, a product of an even integral multiple of a length, which is obtained by multiplying twice the length of a resonator by the refractive index of the resonator, and a beat length obtained by a difference between the propagation constants of two polarization modes. Alternatively, the length of the polarization maintaining fiber is set to be larger than a length, which is obtained by dividing, by the wavelength of the light source, a product of a coherence length and a beat length obtained from a difference between the propagation constants of two polarization modes.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.