Two stages of type II optical parametric amplification of a white-light continuum are used for efficient generation of ultrashort (30-50-fs) pulses at kilohertz repetition rates. Various nonlinear techniques can be used to cover the range from 12 mu m to 280 nm. The amplitude and the phase of the generated UV pulses are characterized by use of frequency-resolved optical gating. (C) 1997 Optical Society of America.