Abstract:
This research focuses on a novel approach of refractive index sensing by utilizing the nonlinear properties
of Hollow Core Photonic Crystal Fibers (HC-PCF) which help ultra-short pulses to get compressed as they
propagate through the fiber. The researchers have been working on optical fiber based sensors in recent
years but their sensing mechanisms rely on quite a few number of parameters.
In this work, a solution to this problem has been proposed which works quite efficiently. Hollow Core
Photonic Crystal Fiber (HC-PCF) filled with either gas or liquid having different refractive indices is
exposed to ultra-short pulses. Due to the variation in refractive indices, the fiber characteristic parameters
for each testing case appear to be unique. Hence for each case, the ultra-short pulse that has been sent
through the fiber changes its shape uniquely as it traverses through the fiber and the power of the output
pulse also appears to be non-identical. By analyzing this change in shape and power, the Material Under
Sensing (MUS) can be easily detected. In this work, successful sensing of gaseous materials and also liquid
materials have been demonstrated.
In terms of gas sensing, as much as 64% compression sensitivity has been achieved alongside 369.07 W of
Power Upsurge for CO2 as MUS. Whereas, if the MUS for hollow core photonic crystal fiber is chosen
with a higher refractive index within the range of 1.35 – 1.455, as much as 11.6% of compression sensitivity
has been achieved with 2313.918W of elevation in Power. This innovative approach holds promise for the
detection of a large variety of petrochemical elements, and biological elements with accuracy and
reliabilit
Description:
Supervised by
Prof. Dr. Rakibul Hasan Sagor,
Department of Electrical and Electronic Engineering (EEE)
Islamic University of Technology (IUT)
Board Bazar, Gazipur, Bangladesh.
This thesis is submitted in partial fulfillment of the requirements for the degree of Master of Science in Electrical and Electronic Engineering, 2024
