High Q Microwave Filter Using Incoherent, Continuous-Wave Supercontinuum and Dispersion-Profiled Fiber

We experimentally demonstrate the combined use of an ultrabroadband, incoherent, continuous-wave (CW) supercontinuum (SC) and a dispersion-profiled fiber to implement a photonic microwave filter with a -factor as high as 140. In our scheme based on spectrum slicing, such a high -factor can be readily achieved due to the following two reasons. The -factor restriction due to the limited wavelength tap number caused by narrow spectral bandwidth of conventional optical broadband sources can readily be solved owing to the ultrabroad bandwidth of the CW SC source. Second, the delay medium based on dispersion-profiled fiber compensates the nonuniform relative time delay between each wavelength filter tap caused by inherent wavelength chirping of conventional frequency domain multichannel comb filters. A fiber dispersion profile is provided for the nonuniform relative time delay compensation.