A terahertz plastic wire based evanescent field sensor for high sensitivity liquid detection.
A highly sensitive detection method based on the evanescent wave of a terahertz subwavelength plastic wire was demonstrated for liquid sensing. Terahertz power spreading outside the wire core makes the waveguide dispersion sensitive to the cladding index variation, resulting in a considerable deviation of waveguide dispersion. Two liquids with transparent appearances, water and alcohol, are easily distinguished based on the waveguide dispersion, which is consistent with theoretical predictions. A melamine alcohol solution with various concentrations is identified successfully, and the detection limit is up to 20ppm, i.e. equivalent to the index variation on the order of 0.01.
You
Borwen
B
Institute of Electro-Optical Science and Engineering and Advanced Optoelectronic Technology Center, National Cheng Kung University, 1 University Road, Tainan 70101, Taiwan, R.O.C.
Liu
Tze-An
TA
Peng
Jin-Long
JL
Pan
Ci-Ling
CL
Lu
Ja-Yu
JY
D000438:Alcohols / Q000737:chemistry; D003198:Computer Simulation; D004867:Equipment Design; D005336:Fiber Optic Technology; D055095:Optics and Photonics; D010969:Plastics; D055053:Terahertz Radiation; D055068:Terahertz Spectroscopy / Q000379:methods*; D014227:Triazines / Q000737:chemistry*
D000438:Alcohols; D010969:Plastics; D014227:Triazines; C011907:melamine