An optically modulated signal is generated for use in transporting data by generating a so-called sub-carrier modulated optical signal and, then, vector modulating the sub-carrier modulated optical signal to yield the desired modulated optical signal for transmission. The vector modulation includes a phase component and an amplitude component. In one specific embodiment of the invention, an apparatus for use in generating a modulated optical signal includes a generator to generate a sub-carrier modulated optical signal including an optical carrier and at least one sub-carrier and an analog vector modulator coupled to receive both the sub-carrier modulated optical signal from the generator and a data signal. The analog vector modulator generates an output optical signal by phase modulating and/or amplitude modulating the sub-carrier of the received optical signal in response to the data signal.