Nonlinear optical response, all optical switching, and all optical information conversion in NbSe nanosheets based on spatial self-phase modulation.

An efficient liquid phase exfoliation method has been developed for the preparation of high quality NbSe2 nanosheets. The pure nonlinear optical properties of these nanosheets have been investigated using three different wavelength continuous wave (CW) lasers. The spatial self-phase modulation (SSPM) effect can be observed clearly in solution dispersions of (NbSe2). The experimental data show that the diffraction is caused by the third-order optical nonlinearity of NbSe2. The third-order nonlinearity susceptibility χ(3) of NbSe2 is about 10-9 e.s.u. by analyzing the experimental results. The relaxation time in the dynamic relaxation is about 1.38 s, 1.58 s, and 1.15 s for 532 nm, 671 nm, and 457 nm, respectively. In addition, the realization of all-optical switching based on SSPM, particularly two-color intrachromatic coherence, indicates that the generation of electron coherence is a universal characteristic of layered quantum materials. All optical information conversion based on the SSPM is also confirmed experimentally. Our experimental results have simple potential application prospects for NbSe2 based on its nonlinear optical response.