Month: May 2021

42. New paper on WGMs via plasmonic nanowire

We have a new paper in Materials Research Bulletin to be published in a special issue on Recent Advances in Functional Materials

The paper is about “Sub-wavelength plasmon polaritons channeling of whispering gallery modes of fluorescent silica microresonator”

Individual spherical objects, such as a silica-microsphere, when excited with a laser under certain conditions, exhibit a set of optical resonances called as “whispering gallery modes” (WGMs). These modes are very sharp (high Q value) and can be harnessed as optical resonators. An interesting prospect is to channel the WGMs through a nanoscale plasmonic waveguide, such as a single silver nanowire, and study the optical emission.

Motivated by this prospect, Sunny Tiwari and Chetna Taneja from my group experimentally show how to channel WGMs through a plasmonic silver nanowire waveguide. They go a step ahead and show the spectral and angular characteristics of such a hybrid optical system. These experiments motivate further questions related to micro-resonances and angular spectrum distribution in dielectric-plasmonic hybrid systems, and can be harnessed to design compact micro-lasers and on-chip couplers. With some effort, they can also be optically trapped and manipulated.

arxiv link to the paper : https://arxiv.org/abs/2105.10698

DOI of the published paper: https://doi.org/10.1016/j.materresbull.2021.111412

41. New paper

A small thing to cheer during these gloomy times…

A new collaborative paper in Optics Express on modal and wavelength conversions in plasmonic nanowires

Work done by Adrian, Deepak K Sharma et al,
as part of Ifcpar Cefipra grant

We show that plasmonic nanowire-nanoparticle systems can perform nonlinear wavelength and modal conversions and potentially serve as building blocks for signal multiplexing and novel trafficking modalities. When a surface plasmon excited by a pulsed laser beam propagates in a nanowire, it generates a localized broadband nonlinear continuum at the nanowire surface as well as at active locations defined by sites where nanoparticles are absorbed (enhancement sites). The local response may couple to new sets of propagating modes enabling a complex routing of optical signals through modal and spectral conversions. Different aspects influencing the optical signal conversions are presented, including the parameters defining the local formation of the continuum and the subsequent modal routing in the nanowire.

Link to the paper: https://doi.org/10.1364/OE.421183