Re-measurement of the transition frequencies, fine structure splitting and isotope shift of the resonance lines of lithium, sodium and potassium

Performing laser-atomic beam spectroscopy, we have remeasured the transition frequencies and the fine structure splitting of the lithium, sodium and potassium resonance lines. Additionally, the isotope shifts Li-6-Li-7 could be determined with high accuracy. Transition frequencies were determined by means of a high-precision lambdameter working at vacuum conditions, calibrated by saturation absorption of I-127(2). Frequency differences up to 1 THz could be determined with the help of a carefully calibrated marker etalon with systematical errors smaller than 1 MHz.