Font Size: a A A

Fiber Sensor Based On Surface Plasmon Resonance With Indium Tin Oxide Film

Posted on:2022-03-29Degree:MasterType:Thesis
Country:ChinaCandidate:J P ChenFull Text:PDF
GTID:2518306515963949Subject:Physical Electronics
Abstract/Summary:PDF Full Text Request
Surface plasmon resonance(SPR)is an electron density oscillation phenomenon in the metal and dielectric interface,the effective refractive index(RI)of plasmon mode is extremely sensitive to the RI of the material on the metal surface.With tremendous demands for the detection of RI in the realm of biomedicine,biochemistry,materials science,nano-photonics,and environmental monitoring,SPR has been extensively exploited for sensing.For last two decades,photonic crystal fiber(PCF)has attracted considerable attentions in the optical physics community due to its micro volume,flexible structure and excellent transmission characteristics.By tailoring structure parameters of the PCF with SPR,part of the light energy is confined in the fiber core,and a large part of the light field propagates in air holes as an evanescent field.SPR sensors with high sensitivity can be designed and realized.Due to cheaper price and near-infrared operating range,indium tin oxide(ITO)can be exploited as the sensing material instead of the usual gold or silver.Based on the perspective of structure innovation and application requirement,two types of ITO coated PCF-SPR sensors are designed by utilizing the finite element method.The article systematically investigates influences of diverse structure parameters on its sensing features to obtain higher sensitivity and figure of merit(FOM).A micro-polishing PCF-SPR sensor is designed and demonstrated in this dissertation.The ITO coated sensor consists of 3 layers of big air holes and 2 small air holes.The sensitivity seldom depends on the sizes of big air holes which leads to a sensor with high structure tolerance.A tiny polishing depth ensures the mechanical strength of the polished fiber.They are decisive factors for mass production and application.The maximum wavelength and amplitude sensitivities of 16200 nm/RIU and 467 RIU-1 can be obtained at the analyte RI range from 1.31 to 1.39,respectively.In addition,the FOM of the sensor can reach up to 140 RIU-1.Most PCF-SPR sensors have been reported to detect RI higher than 1.3,only a few sensors have been proposed to detect low RI.Whereas the anesthetic sevoflurane has a RI about 1.27,the RI of medical oxygen,liquid carbon dioxide,and fluorine-containing organics are in the range of 1.2-1.3.An ITO coated medical sensor is demonstrated to detect low RI.It has certain fabrication tolerance and simple structure.The maximum amplitude sensitivity and FOM of 517 RIU-1 and 87 RIU-1 are obtained in the wide RI range of 1.21-1.31,respectively.Significantly,the wavelength sensitivity can reach up to 33300 nm/RIU that greatly exceeds the existing PCF-SPR sensors for low RI detection.Finally,this proposed medical sensor will be a suitable candidate for pharmaceutical inspection and pharmaceutical leakage monitoring.
Keywords/Search Tags:surface plasmon resonance, photonic crystal fiber, sensor, micro-polishing, low refractive index
PDF Full Text Request
Related items