Coherent random laser based on liquid waveguide gain channels

Abstract

A coherent random laser (RL) is constructed by a sandwich structure consisting of two MgF₂ plates and a highly transparent ultra-thin liquid active layer embedded with Ag nanoparticles, which provides twofold optical confinement by Ag nanoparticle scattering and waveguide structure. Due to the strong optical confinement and the gain-induced effect, a unidirectional low threshold (~1.5 μJ) RL was obtained, which is comparable with conventional optofluidic dye laser. The linewidth of this RL is ~1 nm just above threshold. Compared with polymer film doped with dye molecules, the thin liquid layer is difficult to be bleached due to its fluidity.

Keywords:

• random laser
• multiple scattering
• optofluidic
• waveguide
• laser dye

Additional information

Funding

This work was supported by Major Program of National Natural Science Foundation of China [grant number 60890200]; National Natural Science Foundation of China [grant number 10976017].