Femtosecond ultraviolet autocorrelation measurements based on two-photon conductivity in fused silica

We utilize the two-photon conductivity of a fused-silica substrate to produce a photoconductive switch for use in an intensity autocorrelator for ultraviolet ultrashort pulses. We perform measurements at 267 nm with pulse durations in the range of 110-330 fs and with energies as weak as 10 nJ. Based on the bandgap of fused silica, this device can potentially operate in the wavelength range of 140-280 nm.