Atomically Thin Yellow Pearl: An Impetus for Thermal Nonlinear Optical Effect Assisted Continuous Wave Random Lasing

TL;DR

This study demonstrates that atomically thin yellow pearl enhances thermal nonlinear optical effects, enabling efficient continuous wave random lasing with low threshold and tunable emission, through the creation of a novel 2D heterostructure.

Contribution

The paper introduces a defect-free 2D yellow pearl material synthesized via liquid-phase exfoliation that significantly improves random lasing performance compared to other passive scatterers.

Findings

~25 times gain volume enhancement with 2D-YP@RhB

Incoherent RL emission at ~591 nm with low threshold

Transition from incoherent to mode-tunable coherent RL achieved

Abstract

Above cryogenic temperatures, random laser (RL) emission under continuous wave (CW) optical pumping is often challenging for materials having plenty of lattice defects. Thus, intensive care is required while fabricating the RL device. Synthesis of 2D materials having unique functionality at the atomic limit is necessary for use in such devices. In this work, defects-free 2D yellow pearl (2D-YP) has been synthesized from bulk south sea pearl using liquid-phase exfoliation (LPE) technique. Thereafter, 2D-YP has been employed as passive scatterer to achieve CW pumped RL emission from a conventional gain molecule, i.e., Rhodamine B (RhB). Compared to other semiconductor (TiO2) and 2D (Graphene and h-BN) passive scatterers, ~25 times improvement in gain volume is observed for the disordered system consisting of RhB and 2D-YP, i.e., 2D-YP@RhB, which is found to be due to the formation of a large refractive index gradient, as induced by the thermal nonlinear optical (NLO) interaction. Hence, incoherent RL (ic-RL) emission ~591 nm is reported for 2D-YP@RhB at a lowest threshold input pump power and a linewidth of 65 mW and 3 nm, respectively. Additionaly, a clear transition from ic-RL to mode tunable coherent RL (c-RL) emission is also possible by altering the configuration of the 2D-YP@RhB container. Therefore, the newly designed Van der Waals heterostructure, i.e., 2D-YP with intrinsic photon trapping capability may pave an avenue towards developing future exciting optoelectronic devices.