It is demonstrated that picosecond laser pulses can be characterized with t
he help of a bandwidth-limited time-resolved spectrum (BTS). Using a subtra
ctive double monochromator in combination with a fast streak camera the tim
e dependences of the spectral components are measured under bandwidth-limit
ed conditions. From the experimental data the amplitude and phase of the op
tical field can be reconstructed by applying a simple phase retrieval algor
ithm. (C) 1998 Elsevier Science B.V. All rights reserved.