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.