Optical logic device
US4992654A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Aug 1, 1988 |
| Grant date | Feb 12, 1991 |
| Priority date | — |
| Expiry date | Aug 1, 2008 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG02F3/022
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
An optical logic device consists of a bistable liquid crystal layer (BOD 1) of the thermally-induced birefringent (TIB) type settable by one or more write beams and rfead by a beam of a different wavelength or different light polarization. Thus the read and write beams are optically decoupled. Two such devices (BOD 1 and BOD 2) in tandem form a 3-input AND gate. Here beams A and B are write beams for the first device, (BOD 1), and beam C is the read beam for the first device. For the second device (BOD 2) the write beams are the output of the first device (BOD 1) and beam D, the read beam being beam E. The two read beams have different wavelengths from the write beam. In a second version, the liquid crystal layer is on the base of a prism via which the beams reads it. Write beams go right through the layer, while a read beam is "reflected" from the layer but is modulated by the state thereof. This is an OR gate. Logic assemblies can use combinations of such AND or OR gates.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.