Laser mode locking by active external modulation

Coupling of the longitudinal modes of an ultraviolet argon ion laser has been accomplished by actively modulating the light leaving the laser cavity and feeding back a portion through the output coupling mirror. The method involves no modification of the free-running laser. Several different acoustooptic devices were used to create amplitude and single sideband modulation, which resulted in different pulse train characteristics. A theoretical model of the system has been developed and is compared to the experimental results.<
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