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 tire tuning is adjusted to bring the cavity on resonance irregular dynamic structures are seen. In the unidirectional ring oscillator we observe characteristic rotating vortex patterns.² Introduction of field 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