A novel high-Q optical microwave processor using hybrid delay-line filters

A new hybrid active-passive photonic signal processor, which achieves high-Q microwave bandpass filtering, is presented. It overcomes the problem of achieving very high-Q values, while still operating the active stage with a large gain margin. This enables a significant increase in Q to be obtained, higher filter frequencies, and robust operation. The general synthesis procedure for the hybrid filter is described. The filter response demonstrates very high-resolution microwave signal filtering with a measured Q of 801