2026/07/23 by Aris Koulas-Simos, Pietro Metuh, Athanasios Paralikis +7
#physics.optics #cond-mat.mes-hall
Transition-metal dichalcogenides offer a promising platform for integrated coherent light sources, yet lasing has largely relied on hybrid photonic architectures without direct quantum-optical verification. Here, we demonstrate an all-van der Waals (all-vdW) high-β nanobeam laser based on a WS2/MoSe2/WS2 heterostructure, with the MoSe2 monolayer directly integrated in the WS2-based optical resonator for optimal gain-mode overlap. The devices exhibit efficient exciton-cavity coupling at cryogenic temperatures, strongly directional and linearly polarized emission, soft nonlinear input-output characteristics and linewidth narrowing, enabling lasing operation with β near unity. Excitation-power-dependent photon-autocorrelation measurements reveal a transition from thermal to Poissonian photon statistics, with gpeak(2)(0) decreasing from (1.28 ± 0.09) near threshold to (1.07 ± 0.07) above threshold, directly verifying lasing operation. Furthermore, temporal broadening of the autocorrelation uncovers fluctuation-dominated lasing dynamics. These results establish all-vdW heterostructures as a highly attractive platform for integrated coherent light sources in layered-material photonic architectures and scalable quantum-photonic circuits.