Measuring ultrashort pulses in the single-cycle regime using frequency-resolved optical gating

We present a single-shot frequency-resolved optical gating setup for measurements of ultrashort pulse intensity and phase down to single-optical-cycle durations. Several issues stemming from short durations and extreme bandwidths are addressed. We show that after using spectral response correction, the regular FROG algorithm yields reliable pulse retrievals. We demonstrate measurement of pulse widths down to 4.9 fs.