A system for distributing HDTV signals from a head station to a number of customer stations includes a single head-end optical source having a frequency f.sub.0 and a modulator arranged to receive light from the single optical source. The modulator modulates the light with a sub-carrier multiplex of n channels, where n is an integer greater than 2, the n channels having frequencies f.sub.1, f.sub.2 . . . f.sub.n. The frequencies are separated in frequency-space from each other and from f.sub.0. A broadband passive branched optical network is connected to the output of the modulator and arranged to distribute the modulated signal from the head station to a plurality of customer stations each having a coherent heterodyne receiver.