A NEW METHOD TO MEASURE THE WAVELENGTH OF SINGLE-MODE PULSED LASERS WITH A SCANNING MICHELSON INTERFEROMETER

We report on the possibility to measure the wavelengths of pulsed single-mode lasers by means of a two-beam Michelson interferometer in motion [1, 2]. The comer reflector moves with a nearly constant speed creating a path difference L so that L/C much less than 1/DELTAnu, DELTAnu being the spectral width of the laser to be measured. The reference laser is a stabilized He-Ne (Spectra-Physics, model 117 A) to a precision of the order of two parts in 10(9). The fringe pattern of the two beams (reference beam and measured beam) is sampled simultaneously with a repetition rate of 40 ms. With this new method, the frequency doubled injection-seeded Nd:YAG laser wavelength has been measured with an accuracy of the order of 1.5 in 10(8) almost-equal-to 3 x 10(-4) cm-1 at 532 nm.