Effect of stress on propagation properties of PCF with different design parameters

Abstract

Optical fiber based wavelength division multiplexing (WDM) is widely used to satisfy the high bandwidth demand using optical network. But dispersion, non-linearity and attenuation restrict the wavelength region and transmission bit rate for conventional fiber. Photonic crystal fibers (PCFs) are micro-structured optical fiber which are constructed by single material with multiple air holes periodically arranged around the core. PCFs have ability to be single mode over a broad range of wavelengths. Large number of available design parameters of solid core PCF makes the dispersion, nonlinearity and confinement loss highly configurable. PCFs are of great interest for optical communication in new wavelength regions and for new optical devices. As the stress and thermal effect on PCFs can alter the propagation properties significantly, it is very important to know and study the properties of PCF to fully understand the feasibility of using it as sensor for stress civil structures or acoustic pressure in underwater and underground communication systems. In this research work the effect of external stress and design parameters on propagation properties for square, hexagonal and octagonal air-hole arranged PCFs have been analyzed and simulated. The fiber designs are carried out for all types of PCFs by varying number of air hole rings and air hole diameter and different amount of stress is applied on the PCFs boundary and the effective indices, birefringence are calculated as a function of stress. It is found that external stress on PCF causes stress distribution and fiber deformation in fiber cross section. This deformation is not same for all type of fibers and in all direction (x and y), which causes different effective index and birefringence for all types of PCFs. Results show that external stress affects more on propagation properties of hexagonal PCF than square or octagonal and this effect is lower for larger number of air hole rings and air hole diameter. Our findings will help to find the appropriate designing of PCF for some of particular application.