Demonstration of a compact wavelength tracker using a tunable silicon resonator.

Here, we demonstrate a chip-scale integrated optical wavelength tracker with fast response and compact format. By exploiting the electro-optic(EO) effect on a thermally controlled silicon micro-ring resonator filter, the proposed tracker can operate over a wide wavelength range according to the thermo-optic (TO) effect; meanwhile, the tracker's response speed is greatly improved through the EO effect (i.e. tracking within 1 ns), as compared to the traditional TO controlled methods (typical ~10 μs). With the integration of a photodiode onto the photonics chip, the compact chip is with a footprint of 0.5 mm × 1.5 mm. This tracker has potential applications for wavelength tacking in advanced DWDM network systems, tunable laser sources, and high performance optical sensors.