1982 Volume 48 Issue 12 Pages 1584-1589
Power density distribution of high power CO2 laser beam is successfully measured using a system designed especially. An infrared detector with single element of HgCdTe is used in the system. Incident beam is weakened to suit the sensitivity of the detector by applying a beam splitter of Si wafer coated with Au film. Scanning is carried out mechanically, in vertical direction by rectilinear motion of the detector and in horizontal direction by brandishing of the beam reflected from a rotary prism. Micro processors and random access memories are used for data aquisition and processing. Items of representation by the system are such as graphic display of power density distribution, contour lines and a bird's-eye view. Actual value of power density is reckoned using whole power incidence and sum of all data. Threshold power density to evaporate PMMA is estimated by the contour of a crater formed at beam skirts where power density is inclined.
