Seminar: "Microfiber coupled low-dimensional structures for nanophotonic devices" by Prof. Tong
Title:"Microfiber coupled low-dimensional structures for nanophotonic devices"
Speaker: Professor Limin Tong
Affiliation: State Key Laboratory of Modern Optical Instrumentation, College of Optical Science and Engineering, Zhejiang University, Hangzhou, China
Optical microfibers or nanofibers, with diameter close to the wavelength of the waveguided light, leaving a considerably large fractional evanescent fields for coupling low-dimensional functional materials on the surface. Here I introduce our recent progress on microfiber-coupled structures for photonic devices: First, by coating graphene films on a microfiber, and enhancing light-graphene interaction with confined waveguiding modes of the microfiber, we show an all-optical ultrafast graphene modulator with response time down to 2 ps at 1550-nm wavelength. Secondly, by counterpropagating ultrafast pulses in a CdTe nanowire evanescently coupled to microfibers at both ends, and converting the temporal profile of the pulses into the transverse second harmonic spatial image, we demonstrate a single-nanowire optical correlator for femtosecond pulses with energy down to 2 fJ/pulse at 1064-nm wavelength. Finally, by coupling a single Au nanorod with whispering gallery cavity of a microfiber and introducing strong-coupling-induced mode splitting, we show the possibility of squeezing the plasmonic resonance band of the nanorod from 50 nm to 2 nm. Our results suggest that the microfiber is a versatile platform for nanophotonic devices and applications.
 W. Li et al., "Ultrafast all-optical graphene modulator," Nano Lett. 14, 955-959 (2014).
 S. L. Yu et al., "All-optical graphene modulator based on optical Kerr phase shift," Optica 3, 541-544 (2016).
 C. G. Xin et al., "Single CdTe nanowire optical correlator for femtojoule pulses," Nano Lett. 16, 4807-4810 (2016).
 P. Wang et al., "Single-band 2-nm-linewidth plasmon resonance in a strongly coupled Au nanorod," Nano Lett. 15, 7581-7586 (2015).