Optical data link
US4330870A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Sep 5, 1980 |
| Grant date | May 18, 1982 |
| Priority date | — |
| Expiry date | Sep 5, 2000 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04B10/1127
- WIPO fieldTelecommunications
- WIPO sectorElectrical engineering
Abstract
The disclosed optical data link provides full-duplex, high-data rate optical communications between geographically separate data processing facilities by means of identical optical transceivers. Transmitter optics include an LED and a collimating Fresnel lens for providing a collimated, modulated light beam. Receiver optics include a focusing Fresnel lens and a photoreceptor for converting the impinging modulated light beam into corresponding electrical signals, which are amplified by a gain-controlled amplifier. The LED is selectively translatable along its optical axis to provide focal length correction for temperature-induced focal length distortion, while the photoreceptor is selectively translatable along its optical axis to provide, in addition to focal length correction, a preselected amount of optical energy attenuation. To control the output signal level from the gain-controlled amplifier, a microprocessor in the gain control loop is responsive to a signal level code to selectively enable successive levels of electronic attenuation in the gain-controlled amplifier, and, if the dynamic range of electronic attenuation is exhausted without achieving an optimum output signal l…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.