Method of making a short-pass fiber with controlled cut-off wavelength
US6995900B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jan 21, 2003 |
| Grant date | Feb 7, 2006 |
| Priority date | — |
| Expiry date | Jun 12, 2024 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01S2301/02
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
A method of producing a short-pass fiber by drawing a preform for a depressed cladding fiber at a predetermined drawing ratio. The preform has a core of refractive index n0, a depressed cladding surrounding the core and having a refractive index n1, and a secondary cladding surrounding the depressed cladding and having a refractive index n2. The core has a core cross-section and the depressed cladding has a depressed cladding cross-section that is larger than the core cross-section. The drawing ratio is determined based on the parameters of the preform measured along the axis of the preform and based on a desired minimum fundamental mode cutoff wavelength λm. The final core cross-section defines a fundamental mode cutoff wavelength λc such that λc≧λm along the axis. Then the preform is pulled by the thus-determined drawing ratio to produce the short-pass fiber. In some embodiments a test section of the fiber is pulled first before pulling the short pass fiber.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.