Expand this Topic clickable element to expand a topic
Skip to content
Optica Publishing Group

Optical resonances in microcylinders: response to perturbations for biosensing

Not Accessible

Your library or personal account may give you access

Abstract

Whispering gallery modes (WGMs) in dielectric microcylinders are investigated numerically as sensitive probes of the surrounding medium, for applications in chemical sensing and biosensing. We consider a geometry where WGMs are exited via frustrated total internal reflection from a planar dielectric substrate, as reported in recent experiments. The optical coupling between the substrate and the cylinder yields a WGM broadening exponentially decreasing with increasing distance between the cylinder and the substrate. We also consider a separation layer between the substrate and the cylinder that results in a WGM broadening and shift depending on the index mismatch between the layer and the surrounding medium, and find that Q values >105 are possible for a mismatch in the few percent range. For biosensing applications we calculate the effect of single and multiple cylinder-shaped particles of different sizes attached to the cylinder surface to simulate biological analytes. We find not only WGM shifts but also broadenings and splittings acting as sensitive indicators of different properties of the analytes. In particular, in the case of a single particle, both particle size and refractive index can be determined from the WGM shift and broadening, opening the perspective to a new modality of biosensing applicable to single objects such as viruses or bacteria. In the multiparticle case, the results are statistically analyzed in terms of their surface coverage.

© 2008 Optical Society of America

Full Article  |  PDF Article
More Like This
On- and off-optical-resonance dynamics of dielectric microcylinders under plane wave illumination

I. Mahariq and H. Kurt
J. Opt. Soc. Am. B 32(6) 1022-1030 (2015)

Variational principle in whispering gallery mode sensor responses

Iwao Teraoka and Stephen Arnold
J. Opt. Soc. Am. B 25(6) 1038-1045 (2008)

Cited By

You do not have subscription access to this journal. Cited by links are available to subscribers only. You may subscribe either as an Optica member, or as an authorized user of your institution.

Contact your librarian or system administrator
or
Login to access Optica Member Subscription

Figures (9)

You do not have subscription access to this journal. Figure files are available to subscribers only. You may subscribe either as an Optica member, or as an authorized user of your institution.

Contact your librarian or system administrator
or
Login to access Optica Member Subscription

Equations (7)

You do not have subscription access to this journal. Equations are available to subscribers only. You may subscribe either as an Optica member, or as an authorized user of your institution.

Contact your librarian or system administrator
or
Login to access Optica Member Subscription

Select as filters


Select Topics Cancel
© Copyright 2024 | Optica Publishing Group. All Rights Reserved