METHOD OF ELIMINATING OFFSET IN SPOT CENTROID DUE TO CROSSTALK

摘要

There is provided a method of eliminating an offset in a spot centroid due to crosstalk. A crosstalk matrix is used to characterize crosstalk characteristics of a multi-pixel spot-centroid detector. Left-multiplication of signals outputted from the multi-pixel spot-centroid detector, which are affected by the crosstalk, by an inverse matrix of the crosstalk matrix can result in a light-intensity-distribution signal with impacts of the crosstalk substantially removed. Based on this light-intensity-distribution signal, it is possible to derive the spot centroid, with the offset in the spot centroid due to the crosstalk substantially eliminated, resulting in an improved accuracy of the spot centroid detection, as compared with conventional methods.

主权项

1. A method of eliminating an offset in a spot centroid due to crosstalk, comprising:
measuring crosstalk ratios between respective pixels of a detector by a crosstalk-ratio measuring device; arranging the crosstalk ratios between the respective pixels into a crosstalk matrix characterizing crosstalk characteristics of the detector; left-multiplying signals outputted from the detector by an inverse matrix of the crosstalk matrix to derive a light-intensity-distribution signal with impacts of the crosstalk substantially removed; and calculating the spot centroid based on the light-intensity-distribution signal.