SPATIAL-RESOLUTION AND CHANNEL COUPLING IN A PHASE-CONJUGATE RING-RESONATOR

We describe our study of the spatial resolution of a phase-conjugating ring-resonator (PCR) consisting of a Sagnac interferometer and a phas e-conjugating mirror based on four-wave mixing in photorefractive BaTi O3. The use of optical image processing systems depends on the amount of information channels and the nonlinear coupling between the channel s. The spatial resolution or the number of independent pixels is impor tant to describe any image processing system. If the gain of the phase -conjugating mirror is higher than the losses in the passive part of t he system, then the system exceeds the threshold, and without any exte rnally incident signal the resonator shows the effect of self-oscillat ion. From the analysis of this self-oscillation pattern we have calcul ated the spatial resolution of the PCR. Additionally, we try to invest igate the pixel coupling of the system by defining channels in the res onator. By changing the geometrical set-up of the system it is possibl e to observe a controlled coupling between neighbouring channels.