Sweetser J N, Fittinghoff D N, Trebino R
Opt Lett. 1997 Apr 15;22(8):519-21. doi: 10.1364/ol.22.000519.
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 microJ in energy, the nonlinear medium can be removed and the nonlinearity of air can be used to measure the pulse.
