The integration of mechanics, photonics and electronics in the micro domain provides the lead for an exciting field of research called the   Micro-Opto-Electro-Mechanical Systems (MOEMS). Drawing advantages out of the Silicon-on-Insulator (SOI) technology, waveguide based MOEMS has seen the advent of many devices opening up the possibility of a wide range of applications in the field of telecommunication, aerospace, vehicle systems, biotechnology, etc. In order to understand the optical behavior of these waveguide based devices, it is essential to study the modal characteristics of wave propagation for suitable design and modeling, and to study the effects such as thermal, electromagnetic, mechanical, biological, etc. on the system. In this work, an improvised Finite Difference (FD) modeling technique for rib waveguide system is presented, wherein, the method of finite differences is used to solve Maxwell’s scalar wave equation under different wave propagation conditions. Boundary conditions derived from continuity relations are applied between regions of different refractive indices in solving for modal parameters of the waveguide system. The results of propagation factor and mode shapes obtained from FD modeling have been compared with standard Finite Element Analysis (FEA) and Mode solver for the rib waveguide system and a close agreement is observed.

Micro-Opto-Electro-Mechanical Systems (MOEMS), Silicon-on-Insulator (SOI), rib waveguides, propagation constant, Finite Difference (FD) method, Finite Element Analysis (FEA), Mode solver.