High-Precision Positioning via Differential Four-Quadrant Detection

High-precision light spot positioning is essential for a broad spectrum of applications, including optical communication and precision metrology. While recent advancements have primarily focused on algorithmic optimizations to enhance precision, such approaches frequently necessitate intensive raw data processing, resulting in significant latency and high computational overhead. To circumvent these limitations, we propose a differential detection method utilizing a conventional four-quadrant detector. By facilitating the inherent suppression of common-mode noise through differential signal processing, this approach achieves an approximately 20-fold enhancement in the signal-to-noise ratio. Consequently, the positioning precision is improved by 77% compared to conventional detection methods. The seamless compatibility of this method with existing four-quadrant detector architectures underscores its feasibility for practical deployment. Our findings provide a robust framework for advancing laser spot positioning systems, particularly in scenarios requiring ultra-low latency and energy-efficient operation.