We show that frequency-resolved optical gating combined with spectral interferometry yields an extremely sensitive and general method for temporal characterization of nearly arbitrarily weak ultrashort pulses even when the reference pulses is not transform limited. We experimentally demonstrate measurement of the full time-dependent intensity and phase of a train of pulses with an average energy of 42 zeptojoules (42 × 10−21 J), or less than one photon per pulse.
© 1996 Optical Society of America
Original Manuscript: January 11, 1996
Published: June 15, 1996
David N. Fittinghoff, Ian A. Walmsley, Jason L. Bowie, John N. Sweetser, Richard T. Jennings, Marco A. Krumbügel, Kenneth W. DeLong, and Rick Trebino, "Measurement of the intensity and phase of ultraweak, ultrashort laser pulses," Opt. Lett. 21, 884-886 (1996)