Lasing from single, stationary, dye-doped glycerol/water microdroplets located on a superhydrophobic surface

TL;DR

This study demonstrates laser emission from single dye-doped glycerol/water microdroplets on superhydrophobic surfaces, highlighting low-threshold lasing, multimode behavior, and photobleaching effects.

Contribution

It presents the first observation of lasing from stationary microdroplets on superhydrophobic surfaces with detailed analysis of lasing characteristics.

Findings

Lasing achieved with threshold fluence as low as 750 J/cm2

Multimode lasing observed from whispering gallery modes

Photobleaching occurs at pump fluences above threshold

Abstract

We report laser emission from single, stationary, Rhodamine B-doped glycerol/water microdroplets located on a superhydrophobic surface. In the experiments, a pulsed, frequency-doubled Nd:YAG laser operating at 532 nm was used as the excitation source. The microdroplets ranged in diameter from a few to 20 um. Lasing was achieved in the red-shifted portion of the dye emission spectrum with threshold fluences as low as 750 J/cm2. Photobleaching was observed when the microdroplets were pumped above threshold. In certain cases, multimode lasing was also observed and attributed to the simultaneous lasing of two modes belonging to different sets of whispering gallery modes.