Showing papers by "Wing-Ki Liu published in 2014"
TL;DR: In this article, the break up of OCS in intense femtosecond laser radiation using the FEMPULS technique to vary the laser pulse duration from 7fs to 200fs was studied.
28 citations
TL;DR: In this article, the authors presented a theoretical analysis of plasmonic guided modes in a symmetric conductor-gap-dielectric (SCGD) system, which consists of a thin metal conductor symmetrically sandwiched by two-layer dielectrics with low-index nanoscale gaps inside.
Abstract: A hybrid plasmonic waveguide is considered as one of the most promising architectures for long-range subwavelength guiding. The objective of this paper is to present a theoretical analysis of plasmonic guided modes in a symmetric conductor–gap–dielectric (SCGD) system. It consists of a thin metal conductor symmetrically sandwiched by two-layer dielectrics with low-index nanoscale gaps inside. The SCGD waveguide can support ultra-long range surface plasmon-polariton mode when the thickness of a low-index gap is smaller than a cutoff gap thickness. For relatively high index contrast ratios of the cladding to gap layers, the cutoff gap thickness is only a few nanometers, within which the electric field of the guided SCGD mode is tightly confined. The dispersion equations and approximate analytical expressions of the cutoff gap thickness are derived in order to characterize the properties of the guided mode. Our simulation results show that the cutoff gap thickness can be tailored by the metal film thickness and the indices of the cladding and gap materials. The geometrical scheme for lateral confinement is also presented. Such a structure with unique features of low-loss and strong confinement has applications in the fabrication of active and passive plasmonic devices.
16 citations
10 Apr 2014
TL;DR: In this article, a few cycle pulses, uniform-electric-field-ion imaging spectrometer and Dalitz plotting were used to identify two new stepwise processes in the dissociation of the 3+ and 4+ states of N2O in intense few-cycle pulses at 4 × 1015 Wcm−2.
Abstract: Using few cycle pulses, uniform-electric-field-ion imaging spectrometer and Dalitz plotting, we can identify two new stepwise processes, in the dissociation of the 3+ and 4+ states of N2O in intense few cycle pulses at 4 × 1015 Wcm−2. We observe suppression of selective channels at longer pulse length, which we attribute to molecular dynamics on the 2+ state and the shape of the 3+ potential, which influences propagation of the dissociating wave packet.