The filtering and multiplexing of microwave signals in the frequency range of 0.01 to 4 GHz is experimentally demonstrated. Filtering is obtained by the spectral characteristics of a 1.5- µm multimode laser diode (MLD) and the chromatic fiber-dispersion parameter. Multiplexing is based on the use of appropriated optical delays generated by the use of a Michelson interferometer that allows a very precise adjustment of the free spectral range (FSR) of the MLD used. Experimental results are validated by means of numerical simulations. To show potential applications in the area of optical communications, a filtered microwave signal is used as a microwave electric-carrier transmitting TV-video signal on a long-distance optical telecommunication system. This is achieved by using an external modulation technique over 28.3 km of a single-mode standard fiber, and using an MLD diode emitting at an optical wavelength around 1.5 µm.