Improvement in metal vapor laser performance with reduction in localized electric field at electrodes

Electrode geometry plays a vital role in metal vapor laser performance. It has been observed that by modifying the electrode geometry, the electric field enhancement near the electrode can be reduced. Reduction in the localized electric field causes reduction in the phantom current in the metal vapor laser. On replacing the electrode geometry having eight pins with an electrode having the zero-pin configuration, a 10% decrease in the phantom current and a 23% increase in optical output power are observed. The low phantom current is responsible for higher efficiencies, large specific average output power, and improved beam characteristics of that laser in reference to a conventional copper vapor laser. It was also observed that reduction in field enhancement causes reduction in the thermal loading at the cathode fall and in the probability of thermal instability, thereby improving the discharge stability and jitter in metal vapor lasers. This simple and effective technique can also be applied to the systems requiring high current and high-volume stable discharge.