Multiplexed long-range electrohydrodynamic transport and nano-optical trapping with cascaded bowtie photonic crystal nanobeams

TL;DR

This paper proposes a novel photonic crystal nanobeam system that combines electrohydrodynamic transport and optical trapping to manipulate nanoscale particles efficiently using low power.

Contribution

It introduces a cascaded bowtie photonic crystal design enabling long-range particle transport and stable optical trapping at the nanoscale with minimal energy input.

Findings

Achieved particle transport velocities of 30 μm/s.

Successfully trapped 10 nm quantum dots with 10 k_B T potential depth.

Demonstrated low-power operation for nanoscale optical manipulation.

Abstract

Photonic crystal cavities with bowtie defects that combine ultra-high Q and ultra-low mode volume are theoretically studied for low-power nanoscale optical trapping. By harnessing the localized heating of the water layer near the bowtie region, combined with an applied alternating current electric field, this system provides long-range electrohydrodynamic transport of particles with average velocities of 30 $\mathrm{\mu m/s}$ towards the bowtie region on demand by switching the input wavelength. Once transported to a given bowtie region, synergistic interaction of optical gradient and attractive negative thermophoretic forces stably trap a 10 nm quantum dot in a potential well with a depth of 10 $k_\mathrm{B}T$ using a mW input power.