Label-Free Particle Sensing by Fiber Taper-Based Raman Spectroscopy

Author

Edwards, Perry S. ; Janisch, Corey T. ; Bo Peng ; Jiangang Zhu ; Ozdemir, Sahin Kaya ; Lan Yang ; Zhiwen Liu

Author_Institution

Dept. of Electr. Eng., Pennsylvania State Univ., University Park, PA, USA

Volume

26

Issue

20

fYear

2014

fDate

Oct.15, 15 2014

Firstpage

2093

Lastpage

2096

Abstract

A fiber taper-based method for label-free Raman sensing is presented, which exploits the interaction between adsorbed specimen and the exposed evanescence tail of guided pump light. Chemical specificity and detection of microsphere specimens with diameters as small as 1 μm m are shown. To improve the sensitivity, we further propose resonator-enhanced Raman spectroscopy by taking advantage of the power build-up of a resonant mode in a cavity. Proof of concept is demonstrated by incorporating a fiber taper within a fiber ring resonator and locking a tunable laser to a circulating resonant mode. This demonstration shows a modest 40% enhancement of the Raman signal.

Keywords

Raman spectroscopy; adsorption; chemical sensors; fibre optic sensors; laser cavity resonators; laser tuning; optical pumping; Raman signal; adsorbed specimen; cavity; chemical specificity; circulating resonant mode; evanescence tail; fiber ring resonator; fiber taper-based Raman spectroscopy; fiber taper-based method; guided pump light; label-free Raman sensing; label-free particle sensing; microsphere specimen detection; resonator-enhanced Raman spectroscopy; size 1 mum; tunable laser locking; Cavity resonators; Optical fiber couplers; Optical fiber polarization; Optical fiber sensors; Raman scattering; Raman scattering; optical fibers; optical resonators; optical spectroscopy;

fLanguage

English

Journal_Title

Photonics Technology Letters, IEEE

Publisher

ieee

ISSN

1041-1135

Type

jour

DOI

10.1109/LPT.2014.2347970

Filename

6883158