In recent experiments, the shortestduration opticalwaveform measurement ever achieved was made by researchers at Washington State University (WSU, Pullman, WA) and Sandia National Laboratories (Livermore, CA). Previous measurements of ultrashort laser pulses based on crosscorrelation techniques gave only the approximate duration of a light pulse. The frequencyresolved optical gating (FROG) technique developed at Sandia, however, allows measurement of both intensity and phase of a pulse (see Laser Focus World, Oct. 1994, p. 11). Without prior assumptions on the pulse shape, the researchers used the FROG technique to characterize a pulse of less than 10fs duration (less than three optical cycles).
Beamshaping yields 3W singlefrequency CW output at 532 nm