Design of discretely tunable Optical Delay Line on 45 nm SOI GF Fotonix Platform

An integrated tunable delay line circuit based on Mach-Zehnder interferometers is presented on 45 nm Silicon- on-insulator GF Fotonix platform. Different waveguide lengths are studied to quantify the optical delay. Switching algorithm to tune the optical path for measurement of the delay is also presented. Experimental results show ~ 15 ps of delay for 1 mm long waveguide which matches with our simulation data of ~ 13 ps. The statistical data for the extracted group index across various sites and wafers is also presented. This circuit can be further be used for photonic signal processing by varying both the waveguide length and the optical input power.