Adjustment of optical paths difference in Michelson interferometer

In some applications of a Michelson interferometer, in the case of a large spectral width of radiation, in particular, the high contrast of the interference pattern is obtained if only the optical paths difference between interferometer branches is minimal. The proposed paper demonstrates experimentally the technique of decreasing the optical paths difference up to the level of several microns by using the sequence of light sources with different coherence lengths. The possibility is discussed of using the Michelson interferometer as a compound resonator mirror with the controllable reflection for generation of ultra short laser pulses.