Printable Graphene–Insulator–Semiconductor (GIS) Heterostructures for Active Control of Infrared Q‐Switched Laser

Abstract 2D materials have recently attracted extensive attention in solid‐state laser devices due to the improvement of their beam quality and service life. However, most conventional devices suffer from the fixed saturable absorption properties of certain 2D materials and are confined to the determined operation state. Herein, on‐chip electrically tunable infrared laser signals are realized by introducing a novel 2D nanomesh saturable absorber (SA) interaction layer without other tuning elements based on printable graphene–insulator–semiconductor (GIS) heterostructures. The pulse width can be highly controllable ranging from 1 µs to 360 ns under ultralow electrical modulation power (≈10 pA current and <0.5 nW power), thanks to the high conductivity and tunability of graphene. Furthermore, the precise regulation mechanism of the Fermi level of graphene by the heterostructures is comprehensively explored through opto‐electrical characterization with spectroscopic methods. The GIS device introduces a promising way to achieve actively controlled solid‐state optoelectronic and nonlinear photonic devices in the future.