Longitudinal mode control in giant pulse lasers

We have introduced longitudinal mode selection into a giant pulse laser to obtain single mode output from the laser. Some advantages of achieving longitudinal mode control in a giant pulse laser are noted. The methods of mode control used are described. These include orienting various reflecting surfaces in the laser cavity, cooling the ruby laser crystal, and introduction of a saturable dye in the cavity. Methods of measuring the mode structure are given. Results of these measurements with varying degrees of mode control are described in detail. Under some conditions it is possible to obtain essentially single mode behavior from the giant pulse laser.