Optimization-Based Calibration Process for Position-Sensitive Detector Systems

摘要

In this paper, a calibration process for position-sensitive detector (PSD) systems is proposed. In a PSD system using a quadrature detector (QD), various error sources including the QD, circuit components, and mechanical misalignment that appear in actual implementation introduce inaccuracies in the beam position estimation. The error pattern can be non-linear in the beam power, and non-uniform in the beam position. To calibrate the PSD and enhance the estimation accuracy, this work proposes an optimization-based calibration process. The proposed calibration process is comprehensive, correcting all errors at once in the final assembly state, which can reduce the calibration time and cost. Moreover, the result of the calibration is stable with respect to variations in the beam power, gain stage, and beam position. The impressive enhancement in accuracy and stability of beam position estimation is demonstrated experimentally.