Using a 150-mu m-thick CsLiB6O10 crystal, we produced 100-fs, >200-nJ light pulses tunable between 175 and 180 nm by sum-frequency generation at a 1-kHz repetition rate with an all-solid-state laser system mixing the fourth harmonic of a femtosecond Ti:sapphire regenerative amplifier and the idler pulse from a traveling-wave optical parametric amplifier. (C) 2000 Optical Society of America OCIS codes: 190.2620, 190.7110, 320.7110, 160.4330