Acousto-optical mode-locking of a cw Nd:YAG laser

<正>A cw Nd:YAG laser was mounted on an optical rail with very good stiffness.TheYAG rod used had a diameter of 3mm and a length of 56mm.Both ends of it were ARcoated.A Kr lamp and the crystal rod were placed on the two focuses of the single ellip-tical cavity between two parallel plates.The reflectivity of the wedge-type output mir-ror was measured to be 95% at the wavelength of 1.06μm.A Brewster window and a fieldstop were inserted into the resonator.These Bragg acousto-optical modulators could bemade of ZF6 glass or PbMO4 media.A driving frequency of 100MHz was chosen forthe transducer.The two mirrors of the cavity were Placed at a distance of 750mm.In order to realize small changes of the length of the resonator,a special mirror supportand a vernier micrometer gauge with increments of 1μm were designed.