Continuously variable delay lines
US5247388A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | May 27, 1992 |
| Grant date | Sep 21, 1993 |
| Priority date | — |
| Expiry date | May 27, 2012 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG02F2201/20
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
An acousto-optic apparatus is described that varies the time delay of electrical signals over a continuum of delays. In the preferred embodiment, a light source, which can be either coherent or incoherent, emits an optical beam that is focused into an acousto-optic cell. An input electrical signal is used to drive the acousto-optic cell which, in turn, modulates the focused optical beam. Portions of the input optical beam are modulated and diffracted at angles proportional to the frequencies and phases contained in the input electrical signal. By appropriately choosing the cone of angles at which the light is focused into the acousto-optic cell, the diffracted optical beam can be made to overlap with portions of the undiffracted, unmodulated optical beam. All of the light exiting the acousto-optic cell is then collected onto a device for detection. Optical photomixing of the diffracted beam and the undiffracted beam is performed in order to derive the input electrical signal with a time delay. The approach to generating a continuously variable delay maintains a true time delay of the input electrical signal on its electrical carrier frequency, and does not suffer the limitations im…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.