Fail-safe acousto-optic T-couplers for optical communication networks
US4867517A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Jun 1, 1984 |
| Grant date | Sep 19, 1989 |
| Priority date | — |
| Expiry date | Jun 1, 2004 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04B10/27
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
A fail-safe optical T-coupler for coupling a local terminal having at least one light source and at least one photodetector to a segmented optical data bus comprises an optically transparent acousto-optic cell, a pair of collimating lenses for coupling adjacent segments of the data bus to opposite ends of the acoustic-optic cell symmetrically with respect to the optical axis of the coupler so that there is a fail-safe path for transmitting remotely injected light from one segment of the bus to the next, and at least one acoustic driver for coupling acoustic bulk waves into the acousto-optic cell to selectively establish or intensify an ultrasonic grating along an acoustic axis. For interfacing the terminal with the data bus, the collimating lenses couple each light source and of the segments of the data bus to opposite ends of the acousto-optic cell symmetrically with respect to the acoustic axis of the coupler so that the ultrasonic grating Bragg reflects locally injected light from each light source into the data bus. A similar relationship may be maintained between each photodetector and a corresponding segment of the data bus for Bragg reflection of remotely injected light from…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.