Fibre optic single mode rotary joint
US5039193A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Apr 3, 1990 |
| Grant date | Aug 13, 1991 |
| Priority date | — |
| Expiry date | Apr 3, 2010 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04B10/801
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
The invention is a rotary joint for singlemode optical fibers, having a fixed and a rotating part to permit the transmission of optical signals across a rotational interface (such as a winch or turret) with minimal insertion loss and, in particular, low reflections (good return loss). There is no need of conversion to electrical signals; the device is passive. It may be use an oil of refractive index matched to that of the glass fibers and to that of fiber tapers or lenses used to expand the beam emitted from one fiber and contract it for transmission into the other fiber. The device is bidirectional. By use foil, through precision techniques for building and mounting the optical and mechanical components, and by use of advanced bearings, both the insertion loss and unwanted reflections (return loss) can be minimized, thereby making it suitable for use with singlemode fiber. Insertion loss can be further reduced in conjunction with index-matching fluid by using optical elements (lenses, tapers, fibers) having angled or curved facets rather than perpendicular facets. Oil filling has the further advantage of pressure compensation allowing the device to operate at any ambient pressure…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.