Dispersion of nonlinear refractive index in layered WS2and WSe2semiconductor films induced by two-photon absorption.
Both the nonlinear absorption and nonlinear refraction properties of WS2and WSe2semiconductor films have been characterized by using Z-scan technique with femtosecond pulses at the wavelength of 1040 nm. It is found that these films have two-photon absorption response with the nonlinear absorption coefficient of ∼103cm GW-1, and a dispersion of nonlinear refractive index in the WS2films that translated from positive in the monolayer to negative in bulk materials.
Ningning
N
Dong
Yuanxin
Y
Li
Saifeng
S
Zhang
Niall
N
McEvoy
Xiaoyan
X
Zhang
Yun
Y
Cui
Long
L
Zhang
Georg S
GS
Duesberg
Jun
J
Wang