Interferometric detection of mode splitting for whispering gallery mode biosensors

Abstract

Sensors based on whispering gallery mode resonators can detect single nanoparticles and even single molecules. Particles attaching to the resonator induce a doublet in the transmission spectrum which provides a self-referenced detection signal. However, in practice this spectral feature is often obscured by the width of the resonance line which hides the doublet structure. This happens particularly in liquid environments that reduce the effective Q factor of the resonator. In this paper we demonstrate an interferometric set-up that allows the direct detection of the hidden doublet and thus provides a pathway for developing practical sensor applications.

9 pages

References in corpus (2)

• Controlled coupling of counterpropagating whispering-gallery modes by a single Rayleigh scatterer: a classical problem in a quantum optical light
• Demonstration of mode splitting in an optical microcavity in aqueous environment

Cited by in corpus (3)

• Detection of Nanoparticles with a Frequency Locked Whispering Gallery Mode Microresonator
• Theory of the nanoparticle-induced frequency shifts of whispering-gallery-mode resonances in spheroidal optical resonators
• Yield enhancement in whispering gallery mode biosensors: microfluidics and optical forces