An experimental method based on subpicosecond pulse amplification in excimer gain modules for simultaneously generating both ultrafast, energetic UV excitation pulses and ultrafast UV probe continua is described. Subpicosecond pulses at both 308 and 248 nm, with energies of several millijoules at each wavelength, are available from this apparatus for purposes of excitation. A simultaneously generated probe continuum spans the range ˜450 to ˜235 nm. Both the probe continuum and the seed pulses for amplification at 248 nm are produced by focusing 308-nm pulses into high-pressure gases (Ar and H2, respectively). A deduced multiple-pulse structure in the probe continuum limits the time resolution of the apparatus to ˜1 psec. © 1986 Optical Society of America.