Research On The Coupling Characteristics Of The Surface Plasmons Resonator And Its Sensing Applications

The surface plasmons(SPs)are electromagnetic excitations which are closely confined on the metal surface.It can limit the energy on the interface between the metal and the dielectric.SPs can break through the diffraction limit of traditional optical devices effectively and reduce the size of photon devices below half wavelength.By tailoring the metallic nanostructures,a variety of photonic devices with specific uses can be realized.In this paper,by combining the surface plasmon resonant cavity structure and temperature-sensing materials,we obtain two high-sensitivity temperature sensors.The main contents of this dissertation are as follows:(1)We present a SPs multifunction thermal sensor with high sensitivity and systematically study its transmission characteristics and sensing effect.Firstly,the dynamic transmission characteristics of the coupled waveguide system are studied by the coupled mode theory.Secondly,the spectrum and electromagnetic characteristics of the temperature sensor are simulated by the finite element method,and the optical response and sensing characteristics of the sensor are obtained.The results show that the sensor exhibits a great sensing effect and the sensitivity is up to-3.64 nm/?,far better than the same type of thermal sensors.Besides,the device can also serve as band-stop filter.The transmittance of stop-band is as low as 0.1% while that of pass-band is up to 96.1%.The sensor has great potential in multi-purpose nanodevices and scenes that require high sensitivity for real-time temperature sensing.(2)We design a Fano resonance thermal sensor with a semi-square ring resonator.The thermal sensor consists of two metal-insulator-metal(MIM)waveguides side-coupled to a polydimethylsiloxane(PDMS)-sealed semi-square ring resonator.In this work,firstly,the characteristics of the side coupled square ring resonator system are analyzed,and the transmission spectrum of the structure are obtained theoretically and compared with the simulation results.Then the structural dependence of the sensor performance is studied.In addition,the device has high Q value and low loss.The temperature sensors proposed in this paper have the advantage of small sizes and high sensitivity.It can realize the real-time measurement and precise control of temperature in the environment that is hard to reach by traditional temperature instruments.This research offers the prospect for high sensitivity temperature-measurement.