Nonlinear Optical Switching and all-Figures of Merit in Bi2S3-xSex/PMMA Nanocomposite Films Investigated by Z-Scan under Visible CW Laser
Bi2S3-xSex/PMMA nanocomposite films were prepared using a microwave assisted synthesis with different compositions of x. Crystal structure, surface morphology, and optical properties were performed to characterize the prepared nanocomposite films. The crystallinity and optical band gap of the prepared Bi2S3-xSex/PMMA were affected by x. The prepared samples showed a blue shift in the absorption edge. The laser power dependent nonlinear refraction and absorption of Bi2S3-xSex/PMMA nanocomposite films were investigated by using the Z-scan technique. The optical nonlinearity of the nanocomposite films exhibited switchover from negative nonlinear refraction to positive nonlinear refraction to negative nonlinear refraction effect, and from saturable absorption to reverse saturable absorption to saturable absorption with increase and decrease in the composition. An interesting of all-optical figures of merit was reported to assess the nanocomposite films for a practical device. It were calculated the device all-figures of merit based on the nonlinear response, which is important for all-optical switching device. The results demonstrate that the optimized all-optical figures of merit can be achieved by adjusting the composition and input laser power, which can be used for the design of different all-photonic devices, as well as the results of nonlinear switching behavior can be open new possibility of using the nanocomposite films in laser Q-switching and mode-locking.
作者单位：Department of Physics, College of Science
University of Basrah
Saadon Haitham,Abbas Saeed,Shubar Mohammed. Nonlinear Optical Switching and all-Figures of Merit in Bi2S3-xSex/PMMA Nanocomposite Films Investigated by Z-Scan under Visible CW Laser[J].Chinese Optics Letters,2020,18(1):01.