Gain measurement and low-threshold laser operation in non-doped thin films made of a small-molecule organic red-emitter

TL;DR

This paper reports high net gain and low-threshold laser operation in non-doped small-molecule organic films emitting at 640 nm, overcoming fluorescence quenching issues and enabling stable, single-mode organic lasers.

Contribution

It demonstrates high net gain and laser action in non-doped organic films at red wavelengths, a significant advancement over previous fluorescence quenching limitations.

Findings

Achieved net gain up to 50 cm-1 at 640 nm

Demonstrated laser operation with low thresholds

Showed stable lasing in both resonator and random configurations

Abstract

Stimulated emission in small-molecule organic films at a high dye concentration is generally hindered by fluorescence quenching, especially in the red region of the spectrum. Here we demonstrate the achievement of high net gains (up to 50 cm-1) around 640 nm in thermally evaporated non-doped films of 4-di(4'-tert-butylbiphenyl-4-yl)amino-4'-dicyanovinylbenzene, which makes this material suitable for green-light pumped single-mode organic lasers with low threshold and superior stability. Lasing effect is demonstrated in a DBR resonator configuration, as well as under the form of random lasing at high pump intensities.