On the Photorefractive Gunn Effect

TL;DR

This paper models the photorefractive Gunn effect, revealing complex nonlinear behaviors such as wave shedding, suppression, and chaos, influenced by interference fringes and nonlinear dynamics.

Contribution

It introduces a numerical model of the photorefractive Gunn effect, highlighting the limitations of linear stability predictions and uncovering complex nonlinear phenomena.

Findings

High field domains triggered by interference fringes

Complex wave behaviors including chaos and wave suppression

Linear stability estimates are only approximate

Abstract

We present and numerically solve a model of the photorefractive Gunn effect. We find that high field domains can be triggered by phase-locked interference fringes, as it has been recently predicted on the basis of linear stability considerations. Since the Gunn effect is intrinsically nonlinear, we find that such considerations give at best order-of-magnitude estimations of the parameters critical to the photorefractive Gunn effect. The response of the system is much more complex including multiple wave shedding from the injecting contact, wave suppression and chaos with spatial structure.