Nonlinear Optical Absorption in Nanostructures: Progress and Challenges

In the past two decades, there has been a growing interest in studying the nonlinear optical absorption properties of nanostructures, such as zero-dimensional, one-dimensional (1D), and two-dimensional (2D) materials. These nanostructures possess unique optical properties and have potential applications as saturable absorbers and optical limiters. To meet the demands of optoelectronic devices, extensive research has been conducted on various nanomaterials, including graphdiyne, transition metal dichalcogenides, metal-organic frameworks (MOFs), perovskites, black phosphorus (BP), and hybrid nanostructures incorporating 0D, 1D, or 2D materials. However, current materials have certain limitations.

In recent years, there has been significant progress in utilizing low-dimensional materials for optical devices such as saturable absorbers, optical switches, and optical limiters. Despite this progress, these materials still face limitations in terms of their non-linear optical response, stability, saturation intensity, and exciton decay times. Research scientists are constantly working towards discovering low-dimensional materials with strong and rapid nonlinear optical response, adjustable optical absorption, fast recovery time, high optical and thermal damage thresholds, as well as excellent chemical and mechanical stability.