Abstract

We present experimental and theoretical results on the diversity of pattern formation in linear and ring photorefractive oscillators. In a linear oscillator with plane parallel mirrors pumped by counterpropagating beams we observe both periodic patterns (rolls, rhomboids, tiles) and more complex irregular structures [1]. When the cavity is detuned from the pump radiation, so that on-axis emission is suppressed, periodic patterns are dominant. When the tuning is adjusted to b ring the cavity on resonance irregular dynamic structures are seen. In the unidirectional ring oscillator we observe characteristic rotating vortex patterns [2]. Introduction offield rotation into the ring using a dove prism leads to novel structures, including concentric counterrotating rings, each with different numbers of field dislocations. Periodic switching between different dynamics is also seen. A numerical model of the ring dynamics has been used to capture much of the observed behavior.

© 1996 Optical Society of America