Vector Modulation Scheme using Three Phase Modulator

Abstract

A novel optical I-Q modulator circuit consisting of three phase modulator in parallel is proposed. Theoretical analysis is done by the minimization of an error function of an under-determined system, which delivers specific optical phase relationship and modulation constraints to achieve I-Q modulation. A single sideband modulation with carrier suppression is obtained at the output of the proposed architecture, which is in agreement with the analytical development. Numerical demonstration of the performance of the architecture is done by industry-standard software simulation. Scenarios considering both ideal and imperfect power balances and phase relations to the phase modulators are also considered.