Three Phase Spectral Interferometry (3PSI) for recording high dynamic range optical waveforms with <1 ps resolution over >2 ns records applied to closed-loop pulse shaping

We demonstrate a novel spectral interferometry technique that simultaneously captures three spectral interferograms of a signal waveform with a reference pulse. The measured performance is robust to nonidealities and ambient drifts by implementing a precisely calibrated 3x3 Polarization Maintaining (PM) splitter that provides three phase shift differences nominally spaced 120° apart. The system can achieve long record length by implementing three, high-resolution, Virtually Imaged Phase Array (VIPA) spectrometers. Here, we experimentally implement this technique and demonstrate the measurement of waveforms with >2 ns of record while maintaining <1 ps resolution.