Multi-tap all-optical microwave filter with negative coefficients based on multiple optical carriers and dispersive media

An incoherent photonic microwave filter with multiple positive and negative taps based on two sets of optical carriers and dispersive media is proposed. Negative taps are obtained by means of the π phase inversion in a single electro-optic Mach-Zehnder modulator and the modulator V
π
dependence with wavelength. The transfer function of a 5-tap filter with flat passband calculated using the Parks-McClellan algorithm has been measure showing the feasibility of the technique to obtain practical transfer fucntions.