Megapixel ToF Imager with 35um Depth Resolution

IEEE Transactions on Pattern Analysis and Machine Intelligence publishes a paper "Exploiting Wavelength Diversity for High Resolution Time-of-Flight 3D Imaging" by Fengqiang Li, Florian Willomitzer, Muralidhar Madabhushi Balaji, Prasanna Rangarajan, and Oliver Cossairt from Northwestern University at Evanston, IL, and Southern Methodist University, Dallas, TX. The paper has also been publishes in Arxiv.org and IEEE Computer Society Digital Library.

"The poor lateral and depth resolution of state-of-the-art 3D sensors based on the time-of-flight (ToF) principle has limited widespread adoption to a few niche applications. In this work, we introduce a novel sensor concept that provides ToF-based 3D measurements of real world objects and surfaces with depth precision up to 35 μm and point cloud densities commensurate with the native sensor resolution of standard CMOS/CCD detectors (up to several megapixels). Such capabilities are realized by combining the best attributes of continuous wave ToF sensing, multi-wavelength interferometry, and heterodyne interferometry into a single approach. We describe multiple embodiments of the approach, each featuring a different sensing modality and associated tradeoffs."