Reconstruction of dynamical pulse trains via time-resolved multiheterodyne detection

A multiheterodyne technique is presented which can accurately measure the complex spectrum and temporally reconstruct certain dynamic pulse trains. This technique is applied to periodic pulses formed in a LiNb0₃ Mach Zehnder modulator. The spectral amplitude and phase of 20 GHz 66% return-to-zero (RZ) pulses and 10 GHz 50% RZ pulses are measured, and compared to independent measurements from a high resolution optical spectrum analyser. The temporal pulse shape and phase is reconstructed and compared to high speed sampling oscilloscope measurements. This technique is applied to sections of a large single acquisition, allowing the reconstruction of frequency and amplitude modulated pulse trains.