Ultrashort-laser-pulse measurement using swept beams

We demonstrate a frequency-resolved optical gating (FROG) device that uses a sweepshot geometry that combines the advantages of multishot and single-s hot pulse-measurement devices, has only one moving part, a galvanometer, an d requires no computer control. Like a multishot device, it focuses the bea m to a small spot (rather than a line focus) and has a high intensity in th e nonlinear medium. Like single-shot devices, it makes measurements quickly , generating an entire FROG trace on a single camera screen (rather than re quiring many camera downloads). (C) 2001 Optical Society of America.