Stretchable and Broadband Cavity‐Free Lasers Based on All 2D Metamaterials.

The development of two‐dimensional (2D) materials has brought the breakthrough for scientific discoveries and widespread applications in many emerging devices. However, the related study on lasers is rather limited. In this study, a stretchable and broadband cavity‐free laser device based on all 2D metamaterials consisting of molybdenum disulfide (MoS2)/graphene nanocomposites is designed and demonstrated. When the pumping power density of the device is more than 200 W cm−2, multiple pronounced narrow peaks with linewidth <0.5 nm superimpose on the spectra, providing the signature for laser actions. The optical properties of MoS2/graphene meta‐nanocomposites for MoS2 quantum dots (QDs) with different concentration of l‐histidine doping are also examined. It is emphasized that under optimized doping concentration of MoS2 QDs, the laser action of the device can be effectively enhanced. Furthermore, it is shown that the laser action of the devices is controllable by applying an external strain. It is demonstrated that after stretching for more than 200 times, the performance still remains the same with negligible change, indicating the robustness of the device. The presented stretchable laser devices based on all 2D meta‐nanocomposites therefore can open new possibilities for future developments of not‐yet realized optoelectronic devices. [ABSTRACT FROM AUTHOR]