Mid-infrared Vernier racetrack resonator tunable filter implemented on a germanium on SOI waveguide platform [Invited]

Abstract
Currently, most widely tunable lasers rely on an external diffraction grating to tune the laser wavelength. In this paper we present the realization of a chip-scale Vernier tunable racetrack resonator filter on the Ge-on-SOI waveguide platform that allows for wide tuning (108 nm free spectral range) in the 5 m wavelength range without any moving parts. The fabricated racetrack resonators have a loaded Q-factor of 20000, resulting in a side-peak suppression of more than 20 dB, which is more than sufficient for wavelength selection in an external cavity laser.
Description
Keywords
Mid-infrared Vernier racetrack, Resonator tunable filter, Germanium
Citation
Radosavljevic, S., Beneitez, N. T., Katumba, A., Muneeb, M., Vanslembrouck, M., Kuyken, B., & Roelkens, G. (2018). Mid-infrared Vernier racetrack resonator tunable filter implemented on a germanium on SOI waveguide platform. Optical Materials Express, 8(4), 824-835. https://doi.org/10.1364/OME.8.000824