Abstract
Evanescent-wave gas sensing with tapered optical fibers (TOFs) and quartz-enhanced photoacoustic spectroscopy (QEPAS) is reported. The evanescent field of TOFs with diameter down to sub-wavelength is utilized for photoacoustic excitation in photoacoustic spectroscopy. A quartz tuning fork (QTF) with resonant frequency about ~32.75 kHz is used to detect the generated pressure wave. A normalized noise equivalent absorption coefficient of 1.5×10-6cm-1W/√Hz is achieved for acetylene detection with a fiber taper with a waist diameter of 1.1 μm. It is found that QEPAS with TOFs of sub-wavelength diameters exhibit comparable sensitivities with open path QEPAS but with additional advantages of lower insertion loss, easier alignment, and multiplexing capability.
| Original language | English |
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| Title of host publication | Third Asia Pacific Optical Sensors Conference |
| Volume | 8351 |
| DOIs | |
| Publication status | Published - 20 Feb 2012 |
| Event | 3rd Asia Pacific Optical Sensors Conference - Sydney, NSW, Australia Duration: 31 Jan 2012 → 3 Feb 2012 |
Conference
| Conference | 3rd Asia Pacific Optical Sensors Conference |
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| Country/Territory | Australia |
| City | Sydney, NSW |
| Period | 31/01/12 → 3/02/12 |
Keywords
- evanescent field
- gas sensor
- Optical fiber sensor
- photoacoustic spectroscopy
- tapered optical fiber
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Condensed Matter Physics
- Computer Science Applications
- Applied Mathematics
- Electrical and Electronic Engineering