Indian Journal of Engineering & Materials Sciences Vol. 12, February 2005, pp. 12-16 Silica-on-silicon based 1×N optical splitter: Design, fabrication and characterization Aji Baby, C Dhanavantri, J P Pachauri, S Johri, Pawan Kumar & B R Singh* Optoelectronics Devices Group Central Electronics Engineering Research Institute, Pilani, 333 031, India Received 8 December 2003; accepted 10 December 2004 The present paper deals with the design, fabrication technology and performance of silica-on-silicon based 1×4 and 1×8 optical power splitter. The basic waveguide structure with S-bends and Y-junctions have been used for the splitter design using BPM software. The optimized process parameters related to choice of metal masking layer, chemistry used for deep dry etching of core layer, dependence of etch process parameters on anisotropy and sidewall smoothness, dicing and fibre alignment are presented. An indigenously built ECR/RIE system especially for deep dry etching of silica layer is also described. The results on splitting insertion loss and uniformity maximum across the channel measured on 1×4 and 1×8 splitters are presented. IPC Code: H 01 R 31/02 The ever increasing demand of multimedia communications and other digital communication is driving the transition from electronic to optical networks, however, the success of optical networking would heavily depend on the availability of new family of active as well as passive optical components. The major trends in optical networks are rapid capacity expansion and networking which are more adoptable. But the success of optical networking would heavily depend on the availability of new family of optical active as well as passive components. Most of these passive components, till date, have been realised in bulk-optic configuration using micro lenses and prisms and in fibre optic configuration using fused fibre couplers. These bulk- optic and fibre optic approaches have some limitations in terms of productivity, device stability and suitability for integration. A possible approach to overcome this problem is to introduce channel waveguide technologies to form integrated-optic components. A variety of optical materials like glasses, lithium-niobates and III-V semiconductors have been used to realize these components but the dream of integrating every functional devices on a planar substrate is far from realization 1 . Due to their inherent superiority like low insertion loss, possibility of hybrid integration, reproducibility and long term reliability, silica based planar lightwave circuits (PLCs) have lately attracted considerable attention for the development of wavelength division multiplexing(WDM) components. These components are finding application in optical branching, switching and filtering application in WDM optical networks and offer many attractive applications for passive components like splitters, couplers in optical access networks and PLC switches and filters in DWDM networks 2,4 . Future developments are now focused to hybrid integration, in which the PLCs based on silica- on-silicon technology is considered to be the most promising candidate for integration platform because silica based waveguide provides high performance planar lightwave circuits and silicon has excellent mechanical and thermal properties which are suitable for optical bench 5,7 . This paper presents the results of our investigation related to design, fabrication and characterization of silica-on-silicon based 1×N optical power splitter. Our efforts on developing an indigenous deep dry etching system for this work is also included. Design Design of integrated optic (IO) components involves the numerical analysis of geometry and light propagation through it. Various methods like effective index method (EIM), beam propagation method (BPM), finite element method (FEM) and method of lines, can be used for the modelling of different geometries of the integrated optic devices 8,12 . A _____________________ *For correspondence (E-mail:brs@ceeri.ernet.in)