An Integrated Tunable Delay Line for Photonic Computing on 45 nm CMOS based Silicon Photonics Platform

We present an integrated tunable delay line circuit for photonic computing applications on a Silicon-on-Insulator substrate in O-band. Delay tuning is achieved by switching between the different optical path lengths of a Mach-Zehnder Interferometer (MZI) based optical switch. Simulation results indicate that around 12.6ps of time delay is obtained for a 1 mm differential path length of a single-mode silicon waveguide. We also introduce MZI on both signal paths to vary the optical power of the output signal. The proposed circuit, therefore, can be used for performing photonic signal processing by varying both the delay and the power of the input optical signal.