Realization of the all-optical phase modulator, filter, splitter, and self-consistent logic gates based on assembled magneto-optical heterostructures

TL;DR

This paper presents the design and simulation of four all-optical devices—phase modulator, filter, splitter, and logic gates—based on magneto-optical heterostructures utilizing one-way edge modes, enabling multifunctionality without external magnetic fields.

Contribution

It introduces a novel approach to multifunctional all-optical devices using assembled magneto-optical heterostructures with one-way modes, achieving subwavelength scale and multifunctionality without external magnetic fields.

Findings

Achieved a phase modulation range of -π to π.

Designed a perfect filter dividing one-way regions with equal bandwidth.

Developed a multi-frequency splitter with 50/50 splitting ratio.

Abstract

All-optical computing has recently emerged as a vibrant research field in response to the energy crisis and the growing demand for information processing. However, the efficiency of subwavelength-scale all-optical devices remains relatively low due to challenges such as back-scattering reflections and strict surface roughness. Furthermore, achieving multifunctionality through the reassembly of all-optical structures has thus far been rarely accomplished. One promising approach to address these issues is the utilization of one-way edge modes. In this study, we propose four types of deep-subwavelength ($\sim 10^{-2} \lambda_0$, where $\lambda_0$ is the wavelength in vacuum) all-optical functional devices: a phase modulator, a filter, a splitter, and logic gates. These devices are based on robust one-way modes but do not require an external magnetic field, which can allow for flexible assembly. In particular, we investigate a phase modulation range spanning from $-\pi$ to $\pi$, a perfect filter that divides the input port's one-way region into two output one-way regions with equal bandwidth, a multi-frequency splitter with an equal splitting ratio (e.g., 50/50), and self-consistent logic gates. We validate these theoretical findings through comprehensive full-wave numerical simulations. Our findings may find applications in minimal optical calculations and integrated optical circuits.