Iodine-Stabilized 633 nm Diode Lasers for Metrology and Interferometry

Helium-neon lasers at 633 nm are still widely used in interferometers and, stabilized to iodine, serve as secondary frequency standards for the practical realisation of the meter [1]. However, the technical know-how for building and maintaining helium-neon laser tubes is slowly disappearing. Diode lasers are an attractive alternative with respect to availability, cost, output power, size and power consumption. The emission wavelength of 633 nm allows new systems to be easily integrated into existing setups.