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Updated: May 19, 2026

Evanescent Field Based Photoacoustics: Optical Property Evaluation at Surfaces
Published on: July 26, 2016
Evanescent-wave photoacoustic spectroscopy with optical micro/nano fibers
Yingchun Cao1, Wei Jin, Lut Hoi Ho
1Department of Electrical Engineering, The Hong Kong Polytechnic University, Hong Kong, China.
Abstract:
We demonstrate gas detection based on evanescent-wave photoacoustic (PA) spectroscopy with tapered optical fibers. Evanescent-field instead of open-path absorption is exploited for PA generation, and a quartz tuning fork is used for PA detection. A tapered optical fiber with a diameter down to the wavelength scale demonstrates detection sensitivity similar to an open-path system but with the advantages of easier optical alignment, smaller insertion loss, and multiplexing capability.

