Gold Nanomaterial‐Based Optical Modulators for Wideband Pulse Laser Generation

Abstract

Pulsed lasers have wide applications in several fields, such as basic research, telecommunications, and industrial materials processing. A saturable absorber (SA) is a key component for pulse laser generation. However, the current SAs exhibit certain limitations. Hence, developing new nonlinear optical materials as SAs for pulse lasers generation is significantly important in ultrafast photonics and related applications. Metallic nanomaterials have attracted considerable attention because of their higher nonlinearity coefficients and wideband nonlinear response, which are induced by the surface plasmon resonance (SPR) effect. The SPR effect depends on the size and morphology of materials. Thus, the nonlinear optical absorption effect of gold nanomaterials for pulse laser generation must be explored. In this review, the optical properties of gold nanomaterials are introduced, including SPR absorption, photoluminescence properties, and surface‐enhanced Raman scattering effect. Then, the synthesis and characterization of different gold nanomaterials are reviewed. Subsequently, the nonlinear optical characteristics and devices based on gold nanomaterials are also introduced. Furthermore, the generation of different types of lasers using gold nanomaterial‐based devices is also reviewed. A comparison between gold nanomaterials and other SA materials is presented. Finally, the conclusion and outlook on gold nanomaterial‐based nonlinear optical devices are presented.