An integrated tunable laser using nano-silicon-photonic circuits

This paper reports an integrated tunable laser using nano-silicon-photonic circuits. In particular, all the necessary optical functions in an external cavity laser system, including the beam transmission, coupling, filtering and reflection, are realized using waveguide-based circuits. The high light-confinement capability of the nano-silicon waveguides avoids high optical loss in free-space as suffered in the conventional Microelectromechanical Systems (MEMS) tunable lasers, and thus guarantees superior performance. The proposed laser demonstrates large tuning range (45 nm), pure single-mode properties (45 dB side-mode-suppression ratio (SMSR)), and relatively high output power (~1 mW).