Stabilization of a ruby laser using an He-Ne laser as a frequency reference
Bondarenko A.N. , Kruglov S.V.
A method is proposed for active stabilization of the ruby-laser frequency. The gist of the method is that the Q of the laser resonator is chosen to be low enough to make the lasing frequency and its stability governed by a highQ Fabry-Perot interferometer placed inside the resonator at a small angle to its axis. The distance between the interferometer mirror is rigidly stabilized with the aid of an electron-optical negative-feedback system that consists of a stabilized He-Ne laser, a photoreceiver, and a differential amplifier. The absolute instability of the frequency amounts to 3X 10~3 cm-1.