Strong Ultrafast Saturable Absorption and Nonlinear Refraction of Some Non-van der Waals 2D Hematene and Magnetene Nanoplatelets for Ultrafast Photonic Applications.

In the present work, some non-van der Waals (non-vdW) 2D materials, namely, hematene and magnetene nanoplatelets, were synthesized starting from hematite and magnetite ores, respectively, using a green synthesis method, and they were dispersed in water. Then, their ultrafast nonlinear optical (NLO) response was studied under 50 fs, 400 nm laser excitation. Both non-vdW 2D materials revealed strong saturable absorption with NLO absorption coefficient β, saturable intensity, and modulation depth of about -33.2 × 10