CROSS-DISCIPLINARY PHYSICS AND RELATED AREAS OF SCIENCE AND TECHNOLOGY |
|
|
|
|
Nonresonant and Resonant Nonlinear Absorption of CdSe-Based Nanoplatelets |
Li-Bo Fang, Wei Pan**, Si-Hua Zhong, Wen-Zhong Shen** |
Laboratory of Condensed Matter Spectroscopy and Opto-Electronic Physics, and Key Laboratory of Artificial Structures and Quantum Control (Ministry of Education), School of Physics and Astronomy, Shanghai Jiao Tong University, Shanghai 200240
|
|
Cite this article: |
Li-Bo Fang, Wei Pan, Si-Hua Zhong et al 2017 Chin. Phys. Lett. 34 098101 |
|
|
Abstract We present a comprehensive understanding of the nonlinear absorption characteristics of CdSe-based nanoplatelets (NPLs) synthesized by the solution-phase method and the colloidal atomic layer deposition approach through $Z$-scan techniques at 532 nm with picosecond pulses. The CdSe NPLs exhibit strong two-photon induced free carrier absorption (effective three-photon absorption) upon the nonresonant excitation, resulting in a remarkable optical limiting behavior with the limiting threshold of approximately 75 GW/cm$^{2}$. A nonlinear optical switching from saturable absorption (SA) to reverse saturable absorption (RSA) with increasing the laser intensity is observed when coating CdSe NPLs with a monolayer of CdS shell to realize the resonant absorption. The SA behavior originates from the ground state bleaching and the RSA behavior is attributed to the free carrier absorption. These findings explicitly demonstrate the potential applications of CdSe-based NPLs in nonlinear optoelectronics such as optical limiting devices, optical pulse compressors and optical switching devices.
|
|
Received: 27 April 2017
Published: 15 August 2017
|
|
PACS: |
81.05.Dz
|
(II-VI semiconductors)
|
|
81.07.-b
|
(Nanoscale materials and structures: fabrication and characterization)
|
|
42.65.-k
|
(Nonlinear optics)
|
|
42.70.Nq
|
(Other nonlinear optical materials; photorefractive and semiconductor materials)
|
|
78.67.-n
|
(Optical properties of low-dimensional, mesoscopic, and nanoscale materials and structures)
|
|
|
Fund: Supported by the National Natural Science Foundation of China under Grant Nos 61234005 and 11304197. |
|
|
|
Viewed |
|
|
|
Full text
|
|
|
|
|
Abstract
|
|
|
|
|