1. The Path to Optical Sorting of Large Dielectric Microparticles with Whispering Gallery Modes
Alex King, Nathan Jordan, Dr. Oleksiy Svitelskiy
Gordon College, Physics Department
IMECE-89301
IMECE Track 15-1
NSF Research Poster Competition
Project Objectives
Background
Experimental Setup
Take data on optical whispering galleries in microspheres
Use resonant modes to move particles of various materials
Begin sorting particles by size and geometric perfectness
Resonance detection in microspheres along microfibers
Acoustic whispering gallery analog to optical whispering galleries
Light tweezing
Photon momentum transfer
Proposed particle-sorting, microfluidic, optic chip [2]
Data and Results
Microfiber in mount and sphere, attached by probe to microfiber
Future Studies
Light trapped in a sphere attached to a fiber
Larger microspheres have deeper and more precise resonances
Placing microspheres in water reduces the intensity of resonances and broadens the peaks
Spectra: 45±3μm diameter sphere in air, laser light
Circled double-peak, Lorentzian fit, 𝑅 2 =0.884
Spectra: 17±3𝜇𝑚 Barium Titanate sphere in air, laser light, with single peak fitted by Lorentzian curve, 𝑅 2 =0.987
Attempt optically resonant motion using Barium Titanate microspheres
Produce consistent microfibers
Create and experiment with etched light guides
Induce predictable optically resonant motion.
Create a microfluidic, optic chip that utilizes this effect to sort particles
Conclusions
Larger microspheres require precisely tuned wavelengths of light to optically resonate
Moving larger microspheres is easier due to more precise, intense peaks
Resonances: white light in air
Resonances: white light in water
Acknowledgments
Publications
References
The authors thank Principal Investigator, Oleksiy Svitelskiy and Program Director, Irina Dolinskaya for funding from grant CMMI –
The authors would also like to thank NSF for supplemental travel funds to this competition from grant CMMI
None at current time
[1] Y.Li et. al, Light: Science & Applications 2 [OS1] , e64 (2013)
[2] O.Svitelskiy, Giant Resonant Forces in Optical Whispering Galleries, Senior Seminar (2017)