Intensity Dependent Thresholding and Switching in the Photorefractive 'Bridge' Mutually Pumped Phase Conjugator,
Abstract
The large electro-optic coefficient of photorefractive material such as barium titanate has allowed the observation of exotic phase conjugators such as the Self-Pumped Phase Conjugator(SPPC) and, more recently, the Mutually Pumped Phase Conjugator (MPPC), in which two simultaneous phase conjugate (PC) outputs are produced by the interaction of two mutually incoherent beams within a photorefractive crystal. Several generic MPPC configurations have been reported, differing more in their exact beam geometry rather than the physical mechanism responsible for the effect. These geometries include the Double Phase Conjugate Mirror (DPCM), the Mutually incoherent beam coupler (MIBC), the Bird-Wing Phase Conjugator (BWPC), the Frogs Legs Conjugator and the Bridge Conjugator. Both the DPCM and MIBC have been shown to possess input beam intensity ratio dependent reflectivities and thresholds, and these properties have been utilised in the DPCM for image processing applications. Here we report the observation of total input intensity, rather than intensity ratio, dependent reflectivity from the Bridge MPPC, which has allowed the investigation of effects such as optical thresholding, bistable and hysteretic switching, and optical flip-flop type behaviour.
Document Details
- Document Type
- Technical Report
- Publication Date
- May 22, 1992
- Accession Number
- ADP006795
Entities
People
- Robert W. Eason
- Stephen W. James
Organizations
- University of Southampton