Highly selective Microwave Photonic filters based on new FBGs-EDF recirculating cavities and tuned modulators

We present a microwave photonic filter featuring the highest Q ever reported The filter structure is based on a modified gratings and Erbium Doped Fiber based structure. Q factors over 3000 are demonstrated when a tuned modulator is used in combination with the recirculating approach. Also comb RF filters for specific applications have been implemented. Finally, we investigate the possibility of using lasing from the cavity to feed the recirculating structure. This opens the path for RF filters with higher selectivity and low cost since no external source is required. Experimental measurements illustrate other interesting effects in these systems, which are generally employed to optimize the RF filter response.