Method of determining changes in the refractive index of an optical waveguide
US5550948A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Mar 8, 1995 |
| Grant date | Aug 27, 1996 |
| Priority date | — |
| Expiry date | Mar 8, 2015 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG02B6/02152
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
A method of controlling the polarization properties of a photo-induced device in an optical waveguide and a method of investigating the structure of a light guiding body such as an optical waveguide are disclosed. A device, such as gratings, is written by exposing one side of the optical waveguide to light. The unexposed side is then exposed to an amount of light sufficient to impart the desired birefringence to the written devices. The birefringence can be minimized in the written device by exposing the opposite side to light in an amount sufficient to minimize the amount of birefringence. The light guiding body is investigated by cleaving the elongated light guiding body, such as an optical waveguide, to expose its cross-section. The cleaved section is then treated to expose difference between the core and cladding. Treatment may include etching in an acid or base. The cross-section is then profiled with a scanning probe microscope such as an atomic force microscope to investigate the structure of the light guiding body. The difference in refractive index can be determined across the cleaved endface based on differences in the etched depth.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.