IODINE-STABILIZED HE-NE-LASER AT LAMBDA=633 NM - DESIGN AND INTERNATIONAL COMPARISON

A portable He-Ne laser at 633 nm, frequency stabilized by saturated ab sorption in (127)/(2) and built at the Institute for Atomic Physics, I nstitute for Physics and Technology of Radiation Devices is discussed, The construction of laser head and electronic servo control unit is d escribed. The principle of the arrangement of the electronic circuits in the electronic unit and the tuning procedure of the chosen componen ts are presented. Recent results of an international comparison held a t Bureau International des Poids et Mesures (BIPM) was used to charact erize the performance of the RO.2 laser against the BIPM4 laser. The m ean laser frequency difference calculated on a set of 13 matrix determ inations was: Delta nu=nu(RO.2)-nu(BIPM4)=1.23 kHz with a repeatabilit y of R(nu(RO.2))=+/-6.8 kHz. The frequency stability expressed as rela tive Allan variance for sampling time, tau=10(2) s, was calculated fro m a 40,000-s time interval as sigma(nu)/nu=1.78x10(-12). All measureme nts were made under the restrictions of the Recommendation 3 (Cl-1992) for the lasers suitable for the practical realization of the meter. ( C) 1996 Society of Photo-Optical instrumentation Engineers.