Basic Study on laser Oscillator and Characteristics of Beam

Study on Materials Processing by High Peak Short Pulse CO₂ Laser (Report 1)

Abstract

It is very difficult to obtain high quality without cracks and charring by heat affection in the field of materials processing on ceramics or fibre reinforced plastics (FRP) by conventional CO₂ laser owing to its low peak power and long pulse duration.
A high peak and rectangular pulse CO₂ laser excited by 1 MHz-silent discharge has developed. With the development of a new electrode system utilizing high dielectric constant ceramics plate, homogeneous discharge of power density up to 355 W/cm³ is obtained. An output peak power of 5 kW and pulse duration of 30 to 150 μs in a stable TEM₀₀ mode operation is attained.
A profile of focused beam can be measured by adopting 'Straight Edge Method' and it was made clear that the laser beam has a performance of convergency based on diffraction theory.