Development of a New Signal Processing System for Pin-Cushion Position Sensitive Detector

Due to its high position resolution and fast speed, the position sensitive detector (PSD) is widely applied in micro displacement measurement. However, almost all PSDs suffer from high nonlinearity. In this paper, three kinds of PSDs and their advantages and disadvantages are introduced. Then principle of pin-cushion PSD is studied, based on which a new signal processing system is designed. The signal processing system consists of a high-precision sensor circuit and a software system integrated with a correction algorithm. The test result shows the linearity of the PSD is greatly improved.