Cascaded Tunable Optical Delay Line based on a Racetrack Resonator with Tunable Coupling and Stable Wavelength

We propose a novel integrated optical delay line based on a cascaded racetrack resonator with tunable coupler by push-pull operation of each stage to stabilize the resonant wavelength. The thermal tuning effect and the photonic characteristics of the whole integrated device is simulated to verify the characteristics of the tunable ODLs. The tuning of hundreds of ps is achievable with a very compact device and very small power consumption. The two-stage configuration can allow for reaching larger delay time or a wider bandwidth depending on the operation condition.