An interferometer type wavemeter is designed and constructed to measure the laser wavelength very accurately. Design parameters and constructional data are described in detail.
In order to test the accuracy of the fabricated wavemeter, the He-Ne laser (Spectra-Physics Model 120S) and the argon ion laser (Spectra-Physics Model 165) are used. Zeeman stablized H -N laser (HP 5500C) is used as the reference laser, and the wavelength of the reference laser is known to be 632 991 353.1 ±8.4 fm. The accuracy of our wavemeter is measured to be $2 × 10^{-6}$ and the measurement time is less than one minitue for one measurement.
Our wavemeter will be further improved to give better accuracy, as good as one part in $10^8$, by the technique of counting fractional fringes which uses phase-lock resolution extender and the more long and accurate optical bench.
