Crossover from Reverse Saturable to Saturable Absorptions in Two-Dimensional Tungsten Disulfide

The Tungsten disulfide atomic layer has enormous scientific merits that play a key role in the nonlinear absorption process. Four distinct excitonic peaks spectra are crucial for identifying polarity of by virtue resonant or non-resonant excitation source 532 nm is enough one-photon optical transition at both low-energy and two-photon higher-energy peaks. exhibited reverse saturable (or positive nonlinear) through two-step process which could be possible due to higher energy In addition, coefficient its interchange have been analytically studied with aid magnitude excited-state cross-section Ground-state cross-section. Besides, various factors affecting Z-scan results discussed.