Switchable plasmonic scattering of nanogaps for linewidth-tunable random lasing

TL;DR

This paper presents a method to achieve linewidth-tunable random lasers using switchable plasmonic scattering in nanogaps, enabling dynamic control over laser linewidth for advanced imaging and detection applications.

Contribution

It introduces a novel approach utilizing nonlinear optical effects to switch between different scattering regimes, allowing continuous linewidth tuning over two orders of magnitude.

Findings

Linewidth can be tuned from narrow to broad by adjusting pump power.

Switchable scattering mechanisms enable dynamic linewidth control.

The method offers potential for high-resolution imaging and biological detection.

Abstract

Linewidth-tunable lasers have great application requirements in the fields of high-resolution spectroscopy, optical communications and other industry and scientific research. Here, the switchable plasmonic scattering of the metal particles with plenty of nanogaps is proposed as an effective method to achieve linewidth-tunable random lasers. By using the nonlinear optical effect of the environment medium, the metal particles demonstrate the transition from local scattering of nanogaps with high spatial frequency to traditional Mie scattering free from detail information with increasing the pump power density. Based on these two scattering processes, random lasers can be continuously driven from a narrow-linewidth configuration exhibiting nanogap effect dominated resonances to a broad-linewidth regime of collectively coupling oscillating among nanowires (or nanoflowers), demonstrating the dynamic range of linewidth exceeds two orders of magnitude. This phenomenon may provide a platform for further studying of the conclusive mechanism of random lasing and supply a new approach to tune the linewidth of random lasers for further applications in high-illumination imaging and biology detection.