摘要
The frequency of digitally controlled iodine stabilized He-Ne laser locked to a hyperfine component in ^127I2 was measured using the National Metrology Institute of Japan's reference iodine stabilized He-Ne laser. This laser is operated under the conditions of the practical implementation and its frequency with respect to the International Committee for Weights and Measure recommended value is known from international comparisons. Adopting a sampling rate of 120 kHz for the control system of an iodine stabilized He-Ne laser enables frequency deviation of the test laser from the reference laser by + 5 kHz (relative accuracy of 1 ×10^11) thus limited only by the reproducibility of the iodine stabilized He-Ne laser itself.