Study of optical modal index for semi conductor rib wave guides using higher order compact finite difference method

In this paper, a higher order compact finite difference method in combination with conjugate gradient iteration scheme has been used for optical modal index study of four different semi conductor rib wave guide structures in GaAs/GaAlAs and GeSi material systems. Obtained results for modal indices and normalized indices are used to optimize the structure parameters of the wave guides under consideration and confirm the degree of guidance for propagating waves through various structures in line with the results as obtained by other researchers. Confinement factors for different structures are calculated in support of the data to verify the acceptability of our method.