A multi-VCR system for dispersion compensation and tunable group delay

The vertically coupled resonator (VCR) provides a new insight into the optical delay lines. However, the group velocity dispersion has remained a significant challenge. Here, we describe a multi-VCR system to solve the problem and achieve a tunable optical delay line. The dispersion and the group delay properties of the system are analyzed both theoretically and numerically. Some practical considerations are also discussed. Its flexibility, robustness, compactness, and zero GVD properties make it advantageous over single vertically coupled resonator delay lines and provide a new way to slow light, filtering and optical communication.