Beam Profiling of a Multimode Laser.

摘要

The experimental investigation into the intensity profile characteristics of a multimode, high-power, continuous-wave, CO2 laser is presented. Quantitative one-dimensional profiles were obtained using an enhanced swept null point calorimeter. Qualitative two-dimensional profiles were obtained using the IR transparency material -- 3M, Type 577. The results were: the beam divergence is 3.75 mrad; the intensity profile is characterized basically by a circular mode pattern, but superimposed by a distinguishable rectangular component; the rectangular component only varies in intensity proportional to the laser power and inversely proportional to the optical path length; the shot stability is about + or - 7 w/sq cm; and the average profile deviation from an idealized 'flat top' profile varies from 11 to 15%. (Author)