Horizontal slot waveguide-based efficient fiber couplers suitable for silicon photonics

Introduction Silicon-on-Insulator is emerging as a very suitable technology to develop silicon-based photonic integrated circuits. This technology is 100% CMOS compatible, allowing the development of planar optical devices and making possible to achieve very large scale integration (VLSI). However, nonlinear effects in silicon are inefficient. Materials which have superior optical properties, such as alloys of Group III and V elements, are commonly used to make lasers and active devices. These materials are regrettably not CMOS compatible. Slot waveguides have recently been proposed for silicon photonics devices [1]. The main advantages of slot waveguides is the possibility of filling the slot region with an active optical material thus enabling modulation, switching, sensing and many other applications which are not feasible with silicon material. In this paper, we design efficient fiber couplers for horizontal slot waveguides.