Analysis and Correction of Smeared Image From Interline-Transfer CCD in Beam Quality Measurement

The smear effect caused by light penetration of interline-transfer (IT) CCD in beam quality measurement (BQM) is detrimental and not analyzed pertinently. This report proposes a mathematical model and a correction method for the smeared image. The smear noise is fitted and subtracted through its correlation with the light signal obtained from the model and pre-calibration. The application in BQM is presented by measuring beam quality factor M2 and power in the bucket (PIB). The results verify the validity of the method. An evaluation standard of the correction effect is also recommended.