3391 | International Journal of Current Engineering and Technology, Vol.4, No.5 (Oct 2014) Research Article International Journal of Current Engineering and Technology E-ISSN 2277 – 4106, P-ISSN 2347 - 5161 ©2014 INPRESSCO ® , All Rights Reserved Available at http://inpressco.com/category/ijcet Compact Low loss Design of SOI 1x2 Y-branch optical power splitter with s-bend waveguide and study on the Variation of Transmitted power with various Waveguide parameters Naga Raju Pendam Ȧ* and C.P.Vardhani Ȧ Ȧ Department of Physics, Osmania University, Hyderabad, India Accepted 20 Sept 2014, Available online 01 Oct2014, Vol.4, No.5 (Oct 2014) Abstract A simple technology–compatible design of silicon-on-insulator based 1×2 optical power splitter is proposed. For developing large area Opto-electronic Silicon-on-insulator (SOI) devices, the power splitter is a key passive device. The SOI rib- waveguide dimensions (height, width, and etching depth, refractive indices, length of waveguide) leading simultaneously to single mode propagation. In this paper a low loss optical power splitter is designed by using R Soft cad tool and simulated by Beam propagation method, here s-bend waveguides proposed. We concentrate changing the refractive index difference, branching angle, width of the waveguide, free space wavelength of the waveguide and observing transmitted power, effective refractive index in the designed waveguide, and choosing the best simulated results to be fabricated on silicon-on insulator platform. In this design 1550nm free spacing are used. Keywords: Beam Propagation Method, Insertion loss, Optical Power Splitter, Rib waveguide, Transmitted power. 1. Introduction 1 Optical power splitter is one of the key passive components in subscribes networks of optical communications to split the power of the optical signal into two branches. Silicon- on – insulator (SOI) material is of interest for integrated optoelectronic circuits since it offers the potentiality of monolithic integration of optical and electronic functions on a single substrate. Moreover, the silicon film of silicon-on-insulator (SOI) substrates can be used as a low loss waveguide. The main advantages of the SOI device technology arise from the strong light confinement in very small waveguide due to the large refractive index difference between silicon and silicon dioxide, and the possibility of suing established silicon microelectronics technology. If refractive index difference is more prevalent to optical power splitters, so waveguide is depending on index difference between core and cladding. Further, silicon-on-insulator (SOI) material based splitters provide some additional advantages like low propagation loss, high reliability and good fiber coupling efficiency due to its excellent inherent mechanical and thermal material properties. This article reports on simulations results for optical power splitters by using a Beam Propagation Method. 2. Design An Optical Waveguide is an electromagnetic feed line, it has various structural phenomenon, there are strip *Corresponding author: Naga Raju Pendam waveguide, buried waveguide, rib waveguide, strip loaded waveguides, and in practical 3D waveguides are straight waveguides, corner-bent waveguides, bent & S-bend waveguides, tapered waveguides, branching waveguides, crossed waveguides, directional couplers. Here we selected rib type branching waveguides, i.e., it is possible to get a single - mode propagation condition, even if the planar waveguide with the same thickness is multi-modal. It is also used for dividing and combing the optical power (H. Nishihara et al, 1989). 2.1. Geometry of rib waveguide Figure 1 shows the rib waveguide cross-section. The two dielectric materials, SiO2 and Si, have n 3, 2 and n 1 refractive indices, respectively, taking into account the material dispersion at the wavelength of interest. There is a relation between the geometrical parameters of the waveguide (Graham T. Reed et al, 2004).    0.3 +  √   ; r =    0.5 (1) Where in equation (1) W is the rib width, H is the inner rib height, r is the fractional height of the side regions compared to the rib center (the outer – inner ratio) as defined in Figure 1. For a better understanding, we will also consider the etching depth P = H (1 - r) which directly gives the edge height of the rib waveguide. In the published studies, waveguides that fulfill this relation have very broad sections, several micron of width and height, and the sensitivity to light polarization have not been