Peak Power 50kW, High Repetition Rate Long-pulse TE-CO2 Laser.

Abstract

A high repetition rate, long-pulse TE-CO2 laser has been developed for hard material processing. A new type of pre-ionization circuit with damping resistor made it possible to stabilize the long-pulse laser discharge. Maximum laser energy is 1.1 J and maximum repetition rate is 500Hz. The 16 μ sec (FWHM) optical pulse of low initial spike is obtained by controlling the discharge current and the gas composition, and the output mirror reflectivity. The initial spike power is reduced below 95 kW and the tail output power is increased to 56 kW. The laser power density at the focal point is about 1.9×108 W/cm2, making it possible to use the laser without causing the breakdown of air insulation. Using the laser, we succeeded in fine-cutting a 0.5mm thick Al2O3 ceramic.