Apparatus for measuring the refractive index of an optical fiber
US4572665A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Nov 9, 1983 |
| Grant date | Feb 25, 1986 |
| Priority date | — |
| Expiry date | Nov 9, 2003 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01N21/412
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
The apparatus described basically includes a vessel (10) which has a horizontal transparent window (11) and contains an index liquid (12). An optical fiber (13) is mounted in this vessel perpendicular to the window (11). Light (14) is launched and focused by a condenser (15) onto fiber (13). The light cone of aperture angle (2.beta.) due to the guided and leaky modes is eliminated using an annular mirror (16) that reflects the remaining portion of the aperture light cone (2.alpha.) escaping laterally from the fiber. This light reflected by the mirror (16) is focused by an annular condenser (18) and reflected onto a detector (20) by a flat mirror (19) with a hole in the center. Measuring the amount of light received by the detector (20) allows the refractive index of the fiber to be determined.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.