© 2019 JETIR February 2019, Volume 6, Issue 2 www.jetir.org (ISSN-2349-5162) JETIREL06032 Journal of Emerging Technologies and Innovative Research (JETIR) www.jetir.org 164 Study of Photonic Crystal Fiber Modeling using COMSOL for Sensor Design: A review Shelej Khera *1 , Parulpreet Singh 2 1,2 School of Electronics and Electrical Engineering, Lovely Professional University, Phagwara-144411, Punjab, India. e-mail: * shelej.22390@lpu.co.in Abstract: This paper describes the study of photonic crystal fiber structure modeling for optical fiber sensor design using COMSOL Multiphysics simulation software. The use of photonic crystal fiber enhances the phase matching between optical fiber core guided modes and plasmon modes. PCF bring new strength to the fabrication of optical sensors since its distinctive capability of guiding the evanescent field penetration. There are certain number of air- holes in the PCF fiber which runs along the length of the fiber. For enhancing the sensitivity of the fiber, some parameters of the air-holes needs to be changed and then the structure is simulated with multiphysics software. By improving the width and depth of resonant curve, which are the two critical parameters, the PCF sensor biosensing performance can be enhanced. Keywords: PCF, Dispersion, Modal, Analyte 1. Introduction Nowadays photonic crystal fibers (PCF) [1] is of much attention all around the world.PCF which is also known as holey fibers are special type micro structured fibers. It consist of central defect region contained by many air-holes, lying along whole length of the fiber. The major difference between the photonic crystal fiber and conventional fiber is due the RI profile of core and cladd region of the fiber.PCF can offer more flexibility [2] than conventional fibers in design of optical properties such as birefringence, dispersion and confinement loss. PCF with low and flattened dispersion are useful for improving optical fiber communication capabilities. It has achieved increased attention because of its novel optical characteristics [3]. PCF guide optical waves through one of the two methods: effective-index guidance and photonic band gap guidance. PCF has two parameters to define its geometrical structure, they are diameter of air hole(D) and pitch length(Λ).By varying this two parameter PCF with different properties can be obtained [4]. The main advantages which PCF offers are like getting good birefringence properties, minimum dispersion, good nonlinearity. Typically, there are many PCF structures for PCF like first one is Hexagonal photonic crystal fiber, in which vertex of an equilateral triangle [5] has air holes. This type of PCF is known as Hexagonal photonic crystal fiber [6]. Apart from the HPCF structure there are other structures available like square lattice PCF, cob web PCF, honeycomb PCF, octagonal PCF and decagonal PCF [7], which has gained utmost importance in nowadays PCF sensor design [7]. 2. Finite Element Method Finite element method is a typical and authentic approach for the engineering recommendations as optical sensors. This is the most suitable tool for simulating the sensor structure and it has different modules like