Accurate Wavelength Measurements of the Absorption Lines in H2O Vapor by a 0.8 µm AlGaAs Laser

Abstract
The first results of accurate measurements of vacuum wavelengths of six spectral lines of a (2, 1, 1) vibration band in H2O were presented using a 0.8 µm AlGaAs laser. For these measurements, the technique known as the coincidence method was employed using a stabilized He–Ne laser as a wavelength standard. Accidental error was kept between 1.7×10-7and 5.5×10-8. Systematic error was estimated as being 2.0×10-8.