Dual-wavelength amplified spontaneous emission from interface-engineered polymer films using atomically thin red coral

Abstract

Naturally available two-dimensional (2D) materials having van der Waal's heterostructure are an impetus for generating amplified spontaneous emission (ASE) from dye-based polymer films. Under continuous wave (CW) laser pumping, the problem of scatterer mobility due to induced thermal gradient can be mitigated by such films. In this work, liquid-phase exfoliation (LPE) method has been used to synthesize 2D red coral (2D-RC) from its bulk form. In order to obtain CW-pumped ASE from a rhodamine B (RhB) dye mixed polyvinyl alcohol (PVA) film, 2D-RC has been used as a passive scatterer. Dual-wavelength ASE at ∼591 nm and ∼626 nm has been obtained by designing a step on the film and by introducing film-glass interfaces. Enhanced ASE has been obtained by designing a film-based Fabry-Pérot (FP) cavity in addition to the interfaces. Far-field diffraction patterns obtained due to induced optical non-linearity and thermal lensing in the system have been used to demonstrate scatterer ability by comparing with other commonly used passive scatterers. Thus, dual-wavelength ASE from dye-mixed polymer films has been demonstrated by means of interface engineering and induced step using the newly synthesized van der Waal's heterostructure, namely 2D-RC, as a passive scatterer which may pave the way towards further exciting NLO effects based applications.