We introduce a transient-grating beam geometry for frequency-resolved optical-gating measurements of ultrashort laser pulses and show that it offers significant advantages over currently used geometries. Background free and phase matched over a long interaction length, it is the most sensitive third-order pulse-measurement geometry. In addition, for pulses greater than ~300 fs in length and ~1 µJ in energy, the nonlinear medium can be removed and the nonlinearity of air can be used to measure the pulse.
© 1997 Optical Society of America
John N. Sweetser, David N. Fittinghoff, and Rick Trebino, "Transient-grating frequency-resolved optical gating," Opt. Lett. 22, 519-521 (1997)