A Quadrant Photodiode is a position-sensitive photodetector divided into four independent sensing areas arranged in a 2×2 layout. By comparing the relative photocurrents from each quadrant, it can precisely determine the position, alignment, or movement of a light spot. Quadrant photodiodes are widely used in beam tracking, laser alignment, optical feedback systems, autofocus mechanisms, and vibration or displacement measurements where high speed and accuracy are required.
Read the blog post introducing our new What is a Photodiode? A Complete Guide covers operating modes, device types, key specifications, and material systems. Engineers new to detector selection will find a clear and practical starting point, along with links to relevant product pages and selection tools.