Measurement of the radius of a high-power laser beam near the focus of a lens

Abstract

The flux-time waveform from a mechanically chopped laser beam is used to find a Gaussian pattern approximating to the distribution of energy in the beam. The technique, which is insensitive to errors in locating the beam centre, has been used to measure the minimum radius of a carbon dioxide laser beam having a continuous power of 2 kW focused into a region less than 2 mm in diameter.