Breaking through Single‐Channel Limitations: Four‐Channel Structured Light Parallel Projection Technology Based on Polarization Multiplexing

ABSTRACT Structured light profilometry has remained constrained by a fundamental bottleneck: the single projection channel. Here, a four‐channel structured light architecture that redefines this limit by harnessing polarization as an additional degree of freedom is introduced. This system combines a digital light processing projector (DLP) with a micro‐polarizer array to achieve pixel‐level superposition of four linear polarization states (0°, 45°, 90°, 135°), boosting transmission capacity by 400% at the hardware level. Beyond hardware, a polarization‐constrained signal separation model that resolves severe non‐orthogonal crosstalk is devised, enabling instantaneous single‐frame channel decoupling with O(1) complexity—an unprecedented capability in polarization multiplexing. This co‐designed hardware‐algorithm framework compresses the projection sequence to 25% of conventional methods and supports sub‐millisecond 3D reconstruction under dynamic and high‐glare conditions, a feat unattainable with existing techniques. This approach transforms structured light into a multi‐dimensional information carrier, laying a technological foundation for ultra‐fast, interference‐resilient 3D sensing in industrial automation, biomedical imaging, and autonomous systems.