Abstract:
In past decades, there have been great interest among researchers to utilize the usage extents of photonic crystal fibers or PCFs, more eminently in sensing purposes. PCFs are compact in nature and can be easily integrated in optical systems. Though many PCF design prototypes are available, an easy fabrication friendly PCF designs are of great need. In our research work, we have implemented three distinct types of sensing mechanisms in photonic crystal fibers; most importantly which can be easily manufactured using current technologies. The designs have been implemented using COMSOL Muliphysics which utilizes the finite element method (FEM). The first type of sensing mechanism involves the launching terahertz wave through PCF cross-section; the Terahertz based sensing. The target analyte are filled inside the core of the PCF sensor and percentage of the output transmitted wave power is measured. In THz based sensing, we have proposed two different types of designs. In the first design, we have analyzed hexagonally defined porous cladding used to detect cyanides; which obtained maximum sensitivity of 99.75%. Next we designed a square structured cross-sectional PCF sensor for sensing of amino acids and the proposed sensor exhibited an optimum relative sensitivity of 99.98%. The second type of sensing mechanism we have analyzed using PCF is Surface Plasmon Resonance (SPR) based sensing. In this design, we have used a combination of gold and titanium dioxide for generating surface plasmon wave, necessary for this sensing mechanism. The sensor presented a remarkably high amplitude sensitivity of 4646.1 RIU-1and wavelength sensitivity of 10000 nm/RIU. Most recently, we have implemented a PCF based Mach Zehnder Interferometer utilizing splitting of surface plasmon mode. The novel sensor evinced an outstanding sensitivity of 14.152 dB/RIU. All the proposed sensor designs have been reviewed in details in the following chapters. It is our hope that the proposed sensor models would have major contributions in analyte sensing in different sectors and industry
Description:
Supervised by
Prof. Dr. Mohammad Rakibul Islam
Department of Electrical and Electronic Engineering,
Islamic University of Technology (IUT),
Boardbazar, Gazipur-1704.
This thesis is submitted in partial fulfillment of the requirements for the degree of Bachelor of Science in Electrical and Electronic Engineering, 2022.
