Nonlinear optical properties of graphdiyne/graphene van der Waals heterostructure for laser modulations

Abstract

The construction of van der Waals heterostructures (vdWHs) is emerging as a promising approach for creating new materials with exotic functionalities and extraordinary optical properties in the field of laser modulations. However, the comprehensive research of vdWHs is still at an early stage that it needs further investigation of the corresponding optical properties and applications. In this paper, graphdiyne/graphene vdWH (GDY/G) is successfully fabricated through liquid-phase epitaxial growth method and its optical nonlinearities are investigated for both pulse laser generation and spatial self-phase modulation (SSPM). Using GDY/G as saturable absorber, the outputs of the passively Q-switched (PQS) Nd:Lu0.5Y0.5VO4 laser at 1343 nm under 878 nm direct pumping are investigated in detail, delivering a better performance than pristine graphdiyne or graphene. Moreover, as carrier for SSPM, GDY/G demonstrates a large nonlinear refractive index in the order of 10−5 cm2 W−1. These advantages can be attribute mainly to accelerated carrier relaxation and enhanced nonlinear optical properties due to synergistic effect of graphdiyne and graphene, which are stacked together to form the vdWH with interlayer coupling. The experimental results indicate that GDY/G possesses large potentials and bright prospects in laser modulations.