1. Third-Order Nonlinear Optical Response near the Plasmon Resonance Band of Cu 2- x Se Nanocrystals
- Author
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Huai-Zhe Xu, Guo-Zhi Jia, Teng-Fei Yan, Lan-Qing Zhou, Yan-Bang Zhang, Xin-Hui Zhang, and Ying Li
- Subjects
Materials science ,Physics::Optics ,General Physics and Astronomy ,02 engineering and technology ,010402 general chemistry ,01 natural sciences ,law.invention ,Condensed Matter::Materials Science ,Optics ,Nanosensor ,law ,Physics::Atomic and Molecular Clusters ,Surface plasmon resonance ,Absorption (electromagnetic radiation) ,Plasmon ,Condensed Matter::Other ,business.industry ,Condensed Matter::Mesoscopic Systems and Quantum Hall Effect ,021001 nanoscience & nanotechnology ,Laser ,0104 chemical sciences ,Nanocrystal ,Femtosecond ,Optoelectronics ,0210 nano-technology ,business ,Excitation - Abstract
The third-order nonlinear optical properties of water-soluble Cu Se nanocrystals are studied in the near infrared range of 700–980 nm using a femtosecond pulsed laser by the Z-scan technique. It is observed that the nonlinear optical response of Cu Se nanocrystals is sensitively dependent on the excitation wavelength and exhibits the enhanced nonlinearity compared with other selenides such as ZnSe and CdSe. The W-shaped Z-scan trace, a mixture of the reversed saturated absorption and saturated absorption, is observed near the plasmon resonance band of Cu Se nanocrystals, which is attributed to the state-filling of free carriers generated by copper vacancies (self-doping effect) of Cu Se nanocrystals as well as the hot carrier thermal effect upon intense femtosecond laser excitation. The large nonlinear optical response and tunable plasmonic band make Cu Se nanocrystals promising materials for applications in ultra-fast all-optical switching devices as well as nonlinear nanosensors.
- Published
- 2017
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