Experimental study of self-injection locking oscillator on copper vapor laser

As a novel method to obtain a low divergence laser beam, a self-injection l ocking oscillator system has been developed for a copper vapor laser. The s ystem is made of one laser tube, and uses temporal superposition of two pul sed discharges, predischarge and main discharge. The laser pulse is produce d in the main discharge by amplifying a seeded laser pulse produced by the predischarge. By optimizing the discharge conditions including an interval period between the two pulsed discharges, a high quality laser beam contain ing 80% of the whole laser beam energy in divergence as small as eight time s diffraction limited has been obtained. The quality of the laser beam is c omparable to that obtained with a conventional injection locking oscillator system consisting of two separate laser tubes. (C) 1999 American Institute of Physics. [S0034-6748(99)03511-X].