An exemplary optical modulator includes an interferometer. The
interferometer includes an input optical coupler, an output optical
coupler, and two or more controllable optical waveguides. Each
controllable optical waveguide connects the input optical coupler to the
output optical coupler and has an electro-absorption modulator along a
segment thereof. Two of the controllable optical waveguides are connected
to transmit to an output of the output optical coupler light of
substantially different maximum amplitude.