On-chip digitally-tunable dispersion management

Abstract

Dispersion management is highly desired in various applications such as microwave photonics and optical communication, helping reduce the delay disorder and modulate the pulse profiles. In this paper, we propose a new concept of digitally-tunable dispersion management. and a digitally-tunable dispersion controller (DTDC) on silicon composed of optical switches and chirped multimode waveguide gratings (CMWGs) is demonstrated for the first time. All the CMWGs are identical and have the same dispersion value of D0 and dispersion ranging from 0 to (2N-1)D0 can be tuned with a step of D0 by switching the propagation path of light. More importantly, the DTDC is circulator-free. finally, a DTDC is realized with four stages of 2-mm-long CMWGs, enabling the dispersion tuning from 0 to 42.8 ps/nm with a step of 2.82 ps/nm.