Continuously Tunable Microwave Photonic Filter Using a Multiwavelength Fiber Laser

A tunable microwave photonic filter is demonstrated by employing a stable multiwavelength erbium-doped fiber laser and a dispersive medium. The specific configuration of the multiwavelength laser allows for adjustment of the number of laser lines, i.e., the optical taps of the filter and their spectral spacing. The transfer function of the filter is continuously tunable, exhibiting transmitted bands of less than 1-GHz bandwidth and sidelobe suppression of -17 dB in the 10-30 GHz frequency range.