Laser beam intensity and wavelength dependent nonlinear absorption in pulse laser deposited WS2 thin films

Dual functionality of surface plasmon resonance and barrier layer on the photosensing and optical nonlinearity of ZnO nanorod arrays

“…Open aperture (OA) z-scan trace was carried out to determine the induced nonlinear absorption (NLA) coefficient β of the samples. 37,50 There are two types of NLA in a NLO material, namely saturable absorption (SA) and reverse saturable absorption (RSA). The SA and RSA processes show a peak and a valley at the focus point in the transmittance, respectively.…”

“…37,42 Negative and positive types of absorptive nonlinearities exhibit SA and RSA processes, respectively. 34,37,50 Nonlinear absorption in NPs is due to various mechanisms such as TPA, RSA, transient absorption, FCA and nonlinear scattering. 37 In semiconductors, RSA is due to nonlinear mechanisms such as TPA, FCA, nonlinear scattering or a combination of these processes.…”