Our experiments have used arrayed traps in the near field of a photonic crystal to selectively capture nanoparticles by size. The photonic crystal is designed to support a guided resonance mode, and the incident laser is tuned to the resonance wavelength. Each hole of the photonic crystal acts as a trapping site.
In this work, we use simulations of particle dynamics to determine the optimal experimental conditions for size selection. We include the effects of optical forces, fluid flow, and Brownian motion and explicitly track the trajectories of particles near an array of trapping sites. We study the effects of varying chamber height, flow rate, and particle concentration on size selectivity and trapping yield. We further present photonic crystal designs for selectively trapping smaller or larger particles out of mixed-particle solutions.
Conference Presentations are recordings of oral presentations given at SPIE conferences and published as part of the conference proceedings. They include the speaker's narration along with a video recording of the presentation slides and animations. Many conference presentations also include full-text papers. Search and browse our growing collection of more than 14,000 conference presentations, including many plenary and keynote presentations.