# Bistability, multistability and nonreciprocal light propagation in Thue-Morse multilayered structures

## TL;DR

This paper explores how quasiperiodic Thue-Morse multilayered structures exhibit bistability, multistability, and nonreciprocal light propagation, enabling the creation of all-optical diodes with potential passive and active implementations.

## Contribution

It demonstrates the nonlinear optical properties of Thue-Morse photonic crystals, revealing direction-sensitive bistability and nonreciprocal transmission for the first time.

## Key findings

- Thue-Morse structures exhibit bistability thresholds sensitive to propagation direction.
- Nonreciprocal light propagation enables all-optical diode functionality.
- Passive schemes achieve diode action without additional pump signals.

## Abstract

The nonlinear properties of quasiperiodic photonic crystals based on the Thue-Morse sequence are investigated. The intrinsic spatial asymmetry of these one-dimensional structures for odd generation numbers results in bistability thresholds which are sensitive to the propagation direction. Along with resonances of perfect transmission, this feature allows to achieve strongly non-reciprocal propagation and to create an all-optical diode. The salient qualitative features of such optical diode action is readily explained through a simple coupled resonator model. The efficiency of a passive scheme, which does not necessitate of an additional short pump signal, is compared to an active scheme, where such a signal is required.

---
Source: https://tomesphere.com/paper/0912.3203