IdealPhotonics' four-quadrant position sensor detector is a spot position detection device based on partitioned photodiodes (typically made of Si or InGaAs materials). It determines the two-dimensional coordinates (X/Y axis offset) of the spot in real time through differential calculation of the output current from four independent quadrants, achieving micron-level accuracy. It is widely used in laser alignment, optical tracking, and precision displacement measurement.While achieving real-time high-precision spot position detection (micron-level resolution) through four-channel differential output, it combines fast response (MHz-level bandwidth) with high linearity (<1% nonlinear error). However, rigorous calibration of the sensitivity consistency across quadrants is necessary to ensure positioning accuracy.