Ti2CTx MXene-based all-optical modulator

MXenes, a new class of 2D transition metal carbides, nitrides, and carbonitrides, have attracted much attention due to their outstanding properties. Here, we report the broadband spatial self-phase modulation of Ti2CTx MXene nanosheets dispersed in deionized water in the visible to near-infrared regime, highlighting the broadband nonlinear optical (NLO) response of Ti2CTx MXene. Using ultrafast pulsed laser excitation, the nonlinear refractive index n(2) and the third-order nonlinear susceptibility chi monolayer mml:mfenced open="(" close=")"3 ml:mfenced of Ti2CTx MXene were measured to be similar to 10(-13) m(2)/W and similar to 10(-10) esu, respectively. Leveraging the large optical nonlinearity of Ti2CTx MXene, an all-optical modulator in the visible regime was fabricated based on the spatial cross-phase modulation effect. This work suggests that 2D MXenes are ideal broadband NLO materials with excellent prospects in NLO applications.