Generation of vacuum ultraviolet radiation for precision laser spectroscopy.

We report on the generation of tunable nanosecond pulsed VUV radiation near 120 nm using difference-frequency mixing in H(2). Our scheme uses two dye lasers, one fixed at 606 nm and the other tunable in the red. These convenient wavelengths simplify the metrology needed for accurate VUV laser spectroscopy. Efficient VUV generation is attained with modest Nd:YAG pump laser energies (approximately 160 mJ at 532 nm), making the scheme attractive even when narrow bandwidths are not essential.