Collimator lens for optical fiber
US4815807A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Sep 11, 1987 |
| Grant date | Mar 28, 1989 |
| Priority date | — |
| Expiry date | Sep 11, 2007 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG02B6/32
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
A collimator lens for an optical fiber is disclosed. The collimator lens comprises a cylindrical member having an effective radius R and effective axial length L. The cylindrical member is formed of optically transparent material having refractive index n.sub.1. The cylindrical member has one circular end portion provided with a connecting portion connectable with a light emitting end face of an optical fiber and the other circular end portion provided with a fresnel lens pattern having a positive focal length F. The focal length F, the effective length L, the effective radius R and the refractive index n.sub.1 are satisfied with the following formula (I) and (II); EQU F/L=tan {sin.sup.-1 (NA/n.sub.1 }/tan {sin.sup.-1 (NA)} (I) EQU R.gtoreq.L.multidot.tan {sin.sup.-1 (NA/n.sub.1)} (II) in which NA is numerical aperture of the optical fiber.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.