Trends in laser equipment

A range of commercially available axial flow CO2 lasers having mean powers of 2kW are normally used for machining or welding nonmetals and steels up to a few millimeters thick. For work at higher powers several continuously rated multikilowatt transverse flow CO2 lasers have been developed. Four industrially rated 5kW(CL5) units have been run routinely on a single-shift basis with a cumulative life already exceeding 13,000 hr. At full power not less than 80% of the beam can be focused into a spot diameter of 0.3mm, using f/4 spherical optics. Near-field and far-field burn patterns on perspex provide qualitative evidence of the very clean transverse mode structure. More precise online measurements at a range of axial position have been made using a beam-scanning quality assurance unit.