# Deterministic and stochastic coarsening control in optically-addressed spatial light modulators subject to optical feedback

## TL;DR

This paper presents two methods, deterministic and stochastic, for controlling domain coarsening in bistable optical systems, demonstrating how to manipulate the speed and direction of domain fronts using parameter variation and noise.

## Contribution

It introduces novel deterministic and stochastic control techniques for domain coarsening in bistable systems, applicable to optical modulators and potentially other systems.

## Key findings

- Deterministic control can steer domain front dynamics in bistable systems.
- Stochastic control uses noise to influence front propagation.
- Both methods effectively manipulate domain growth and coarsening.

## Abstract

Phase separation accompanied by further domain growth and coarsening is a phenomenon common to a broad variety of dynamical systems. In this connection, controlling such processes represents a relevant interdisciplinary problem. Using methods of numerical modelling, we demonstrate two approaches for the coarsening control in bistable systems based on the example of a spatially-extended model describing an optically-addressed spatial light modulator with two color illumination subject to optical feedback. The first method implies varying system parameters such that the system evolves as the pitchfork or saddle-node normal forms. The second method leverages noise whose intensity is used as an additional system parameter. Both, deterministic and stochastic schemes allow to control the direction and speed of the fronts separating spatial domains. The considered stochastic control represents a particular case of the noise-sustained front propagation in bistable systems and involves the properties of the optical system under study. In contrast, the proposed deterministic control technique can be applied to bistable systems of different nature.