Non-Hermitian engineering of synthetic saturable absorbers

TL;DR

This paper presents a novel class of synthetic saturable absorbers using quantum-inspired photonic arrays, demonstrating tunable nonlinear optical filtering with sharp transition thresholds influenced by array size.

Contribution

It introduces a new approach to saturable absorbers based on non-Hermitian photonic arrays with engineered nonlinear optical responses.

Findings

Sharp transition in optical transmission regimes

Threshold intensity can be engineered by array size

Potential applications in laser and optical signal processing

Abstract

We introduce a new type of synthetic saturable absorbers based on quantum inspired photonic arrays whose linear light transport characteristics can be derived via bosonic algebra. We demonstrate that the interplay between optical Kerr nonlinearity, interference effects and non-Hermiticity through radiation loss leads to a nonlinear optical filtering response with two distinct regimes of small and large optical transmissions. More interestingly, we show that the boundary between these two regimes can be very sharp. The threshold optical intensity that marks this abrupt "phase transition" and its steepness can be engineered by varying the number of the guiding elements. The practical feasibility of these structures as well as their potential applications in laser systems and optical signal processing are also discussed.