I. Introduction
The transmission and processing of signals using optical beam as carrier has been a topic of great interest for last five decades where optical waveguides as a fundamental component are widely used. Well-defined refractive index profiles and geometric shapes, with high controllability and reproducibility help to understand the propagation properties in such wave guides more appropriately. Here rib wave guides with arbitrary refractive index profile are considered as this structure allows the greatest versatility in device design though it is relatively easy to develop where the most basic and important step is the modeling process. This plays a very significant role in advancement of optical wave guide components by evaluating the structural design performance through wave guiding and its confinement capability. Additionally, it can reduce the high cost required during the fabrication process by optimizing the design, best suited the initial requirements.