Frequency-stable Nd:YAG lasers in Michelson — Morley experiment

Results of frequency stability of Nd:YAG lasers locked to resonances of high-Q Fabry-Perot sapphire interferometers are reported. The interferometers were mounted on a platform cooled down to the cryogenic temperature; this ensured high long-term laser stability in the Michelson-Morley experiment.