Abstract

Feedback loops constitute a powerful instrument in optics: a light field can be re-injected in a nonlinear device simply by partial reflection on an external mirror. Examples of experimental achievements allowed by the presence of a feedback loop include pattern formation with Kerr slices in single mirror arrangements and chaos in lasers with delayed feedback. In this paper we consider a broad class of systems whose feedback loop is -misaligned. This is the case, for instance, when the external mirror is not perfectly orthogonal to the beam axis, so that the transverse profile of the re-injected beam is laterally shifted. The optical field in a point E(x) within the device is then coupled with E_Δx = E(x + Δx), with Δx lateral shift. This nonlocal coupling is the spatial analogous of temporal delay where the field at time t is coupled with the delayed field at t + Δt. In this work we focus on spatial effects, assuming that the time delay in the feedback loop is negligible as compared with temporal scales of the dynamics of the nonlinear device.

© 2007 IEEE