Influence of Small Impurities in Absorption Cells of I2 Stabilized Lasers upon Their Frequency

The dependence of the frequency of I2-stabilized Ar+ and He-Ne lasers on different I2 cell impurities was investigated. The impurity content is determined via the I2 fluorescence, excited by radiation at 502 nm. Extremely small impurity differences can be detected corresponding to relative frequency shifts of 3 X 10-13.