Nonlinear Coherent Light–Matter Interaction in 2D MoSe2 Nanoflakes for All‐Optical Switching and Logic Applications

Abstract

AbstractA strong nonlinear optical response of 2D MoSe2 nanoflakes (NFs) through spatial self‐phase modulation (SSPM) and cross‐phase modulation (XPM) induced by nonlocal coherent light–matter interactions is reported. The coherent interaction of light and MoSe2 NFs creates the SSPM of laser beams, forming concentric diffraction rings. The nonlinear refractive index (n2) and third‐order broadband nonlinear optical susceptibility (χ(3)) of MoSe2 NFs are determined from the self‐diffraction pattern at different exciting wavelengths of 405, 532, and 671 nm with varying laser intensity. The evolution and deformation of diffraction ring patterns are observed and analyzed by the “wind‐chime” model and thermal effect. By taking advantage of the reverse saturated absorption of 2D SnS2 NFs compared to MoSe2, an all‐optical diode has been designed with MoSe2/SnS2 hybrid structure to demonstrate the nonreciprocal light propagation. Few other optical devices based on MoSe2 and semiconducting materials such as Bi2Se3, CuPc, and graphene have been investigated. The all‐optical logic gates and all‐optical information conversion have been demonstrated through the XPM technique using two laser beams. The proposed optical scheme based on MoSe2 NFs has been demonstrated as a potential candidate for all‐optical nonlinear photonic devices such as all‐optical diodes and all‐optical switches.