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

We report a strong nonlinear optical response of 2D MoSe$_2$ nanoflakes (NFs) through spatial self-phase modulation (SSPM) and cross-phase (XPM) induced by nonlocal coherent light-matter interactions. The interaction light NFs creates the SSPM laser beams, forming concentric diffraction rings. refractive index ($n_2$) third-order broadband susceptibility ($\chi^{(3)}$) are determined from self pattern at different exciting wavelengths 405, 532, 671 nm with varying intensity. evolution deformation ring patterns observed analyzed `wind-chime' model thermal effect. By taking advantage reverse saturated absorption SnS$_2$ compared to MoSe$_2$, an all-optical diode has been designed MoSe$_2$/SnS$_2$ hybrid structure demonstrate nonreciprocal propagation. Also few other devices based on semiconducting materials such as Bi$_2$Se$_3$, CuPc, graphene have investigated. logic gates information conversion demonstrated XPM technique using two beams. proposed scheme potential candidate for photonic diodes switches.