Development of longitudinally excited CO2 laser

• Main Authors: Masroon, N S, Tanaka, M, Tei, M, Uno, K, Tsuyama, M, Nakano, H
• Format: Conference Proceeding
• Language: English
• Subjects: Carbon dioxide; Carbon dioxide lasers; Charging; Discharge; Electrons; Excitation; Gas pressure; High voltages; Lasers; Low cost; MOSFETs; Physics; Service life; Solid state; Spark gap switches
• ISSN: 1742-6588; 1742-6596
• DOI: 10.1088/1742-6596/1027/1/012010

Simple, compact, and affordable discharged-pumped CO2 laser controlled by a fast high voltage solid state switch has been developed. In this study, longitudinal excitation scheme has been adapted for simple configuration. In the longitudinal excitation scheme, the discharge is produced along the direction of the laser axis, and the electrodes are well separated with a small discharge cross-section. Triggered spark gap switch is usually used to switch out the high voltage because of simple and low cost. However, the triggered spark gap operates in the arc mode and suffer from recovery problem causing a short life time and low efficiency for high repetition rate operation. As a result, there is now considerable interest in replacing triggered spark gap switch with solid state switches. Solid state switches have significant advantages compared to triggered spark gap switch which include longer service lifetime, low cost and stable high trigger pulse. We have developed simple and low cost fast high voltage solid state switch that consists of series connected-MOSFETs. It has been installed to the longitudinally excited CO2 laser to realize the gap switch less operation. Characteristics of laser oscillation by varying the discharge length, charging voltage, capacitance and gas pressure have been evaluated. Longer discharge length produce high power of laser oscillation. Optimum charging voltage and gas pressure were existed for longitudinally excited CO2 laser.