Structured Light Imaging under Sunlight Conditions

Quantum-Size-Effect Tuning Enables Narrowband IR Photodetection with Low Sunlight Interference

“…Depth imaging techniques, such as structured light (SL) and time-of-flight (ToF), rely on infrared light pulses toward the object and the photodetection of the backscattered light (Figure a). Ambient illuminationin particular, sunlightcontributes to unwanted background current that degrades the accuracy and resolution of these techniques. − Depth imaging techniques, such as SL, require that the projected pattern’s light intensity be comparable with that of the ambient light; yet sunlight is often 2–5 orders of magnitude brighter than the projected infrared light, making many depth imaging systems unsuitable for outdoor operation. − These systems commonly rely on silicon (Si) photodetectors due to their highly scaled, low-cost production. As the bandgap of Si limits photodetection to wavelengths shorter than 1100 nm, depth imaging systems operate with 850–950 nm light sources. , …”