title: Asymmetric light propagation in composition-graded semiconductor nanowires.
abstract: Asymmetric light propagation is crucial to the development of optical-based functional components in nanophotonics. Diverse configurations and structures have been proposed to allow asymmetrical propagation of photonic signal, but on-chip integration is difficult to achieve due to their complex structure and/or relatively large footprint. Here we report the first design and realization of asymmetric light propagation in single semiconductor nanowires with a composition gradient along the length. We show the asymmetric nanowire waveguides can be synthesized using a simple thermal evaporation and vapor transport approach without involving complicated and costly fabrication processes. Our studies demonstrate the asymmetric nanowire waveguides offer some significant advantages over previous designs, including ultra-low operation power, tunable working wavelength and nanoscale footprint, making them attractive building blocks for integrated photonic circuits.
authors.affiliation: Key Laboratory for Micro-Nano Physics and Technology of Hunan Province, State Key Laboratory of Chemo/biosensing and Chemometrics, College of Physics and Microelectronics Science, Hunan University, Changsha 410082, China.
authors.forename: Jinyou
authors.initials: J
authors.lastname: Xu
authors.forename: Xiujuan
authors.initials: X
authors.lastname: Zhuang
authors.forename: Pengfei
authors.initials: P
authors.lastname: Guo
authors.forename: Weiqing
authors.initials: W
authors.lastname: Huang
authors.forename: Wei
authors.initials: W
authors.lastname: Hu
authors.forename: Qinglin
authors.initials: Q
authors.lastname: Zhang
authors.forename: Qiang
authors.initials: Q
authors.lastname: Wan
authors.forename: Xiaoli
authors.initials: X
authors.lastname: Zhu
authors.forename: Zongyin
authors.initials: Z
authors.lastname: Yang
authors.forename: Limin
authors.initials: L
authors.lastname: Tong
authors.forename: Xiangfeng
authors.initials: X
authors.lastname: Duan
authors.forename: Anlian
authors.initials: A
authors.lastname: Pan