A spatial refractive index sensor using whispering gallery modes in an optically trapped microsphere
Optics
2015-06-26 v1
Abstract
We propose the use of an optically trapped, dye doped polystyrene microsphere for spatial probing of the refractive index at any position in a fluid. We demonstrate the use of the dye embedded in the microsphere as an internal broadband excitation source, thus eliminating the need for a tunable excitation source. We measured the full width at half maximum of the TE and TM resonances, and their frequency spacing as a function of the refractive index of the immersion fluid. From these relations we obtained an absolute sensitivity of 5e-4 in local refractive index, even when the exact size of the microsphere was not a priori known.
Cite
@article{arxiv.physics/0612070,
title = {A spatial refractive index sensor using whispering gallery modes in an optically trapped microsphere},
author = {P. Zijlstra and K. L. van der Molen and A. P. Mosk},
journal= {arXiv preprint arXiv:physics/0612070},
year = {2015}
}
Comments
3 pages, 3 figures