Photonic crystal fiber interferometer coated with a PAH/PAA nanolayer as humidity sensor
| Autor: | Joseba Zubia, Manfred Rothhardt, Cesar Elosua, Diego Lopez-Torres, Joel Villatoro, Kay Schuster, Francisco J. Arregui |
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| Rok vydání: | 2017 |
| Předmět: |
Materials science
Optical fiber 02 engineering and technology 01 natural sciences law.invention Optics law Nano Materials Chemistry Relative humidity Electrical and Electronic Engineering Instrumentation business.industry 010401 analytical chemistry Metals and Alloys Single-mode optical fiber 021001 nanoscience & nanotechnology Condensed Matter Physics Cladding (fiber optics) 0104 chemical sciences Surfaces Coatings and Films Electronic Optical and Magnetic Materials Interferometry Optoelectronics 0210 nano-technology business Excitation Photonic-crystal fiber |
| Zdroj: | Sensors and Actuators B: Chemical. 242:1065-1072 |
| ISSN: | 0925-4005 |
| Popis: | In this paper, an optical fiber interferometric humidity sensor is presented. The device consists of 1 cm-long segment of photonic crystal fiber (PCF) spliced to standard single mode fibers (SMFs), forming an interferometer: the two collapsed interfaces between PCF and SMF segments produce the excitation and recombination of core and cladding modes. The latter interact with a poly(allylamine hydrochloride) (PAH) and poly(acrylic acid) (PAA) polymeric nanocoating deposited on the PCF by the well-established layer-by-layer nano assembly (LbL) technique. Humidity modifies the index of the polymeric nanolayer which in turns alters the cladding modes along the PCF segment and causes a detectable shift to the interference pattern. A study of different nanocoting thicknesses is presented in order to obtain the best possible sensibility for the sensor. Furthermore, the interrogation of the humidity sensor is presented not only by the conventional study of the spectrum shift amplitude, but also making use of the Fast Fourier Transform (FFT), which yields a linearization of the device response. The sensor here presented is reproducible, can resolve 0.074% of relative humidity (RH) and operates in the 20–95% RH range. Moreover, it exhibits response time of 0.3 s, a negligible cross sensitivity to temperature as well as long term stability. |
| Databáze: | OpenAIRE |
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