Method of eliminating offset in spot centroid due to crosstalk

Abstract

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.

Dependencies are inferred from the claim text.