Resonant phase modulator
US4998255A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Oct 11, 1989 |
| Grant date | Mar 5, 1991 |
| Priority date | — |
| Expiry date | Oct 11, 2009 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG02F1/212
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
Apparatus and method for modulating the phase or the amplitude of a monochromatic light beam, the apparatus including in one embodiment a Mach-Zehnder interferometer that consists of two beam splitters or beam combiners, a fully reflective mirror and an electro-optical crystal for modulation of one of two beam components. The electro-optical crystal serves as an optical resonator for the portion of the light beam admitted into the crystal material, using total internal reflection of the light beam from two or more of the crystal surfaces. The crystal has a high finesse so that a relatively small change in voltage applied across the crystal produces a large (.apprxeq.180.degree.) change in the external phase shift associated with the modulated component of the light beam. The modulated and unmodulated light beam components may be recombined for purposes of communication of information, using the mutual extinction of the two beam components when the optical phase shift between the two beam components is approximately 180.degree.. Transverse or longitudinal electro-optical materials can be used for the crystal, and the driving voltages required are less than 50 volts in some configura…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.