Artilux Ge-on-Si ToF Pixel
"Range-imaging is key to many electronics applications such as hand tracking, facial recognition, localization/mapping for navigation, object detection/ranging for autonomous driving, and many others. However, new technologies are needed to enable accurate range-imaging at wavelengths beyond the visible range, in order to ensure eye safety and for better performance. One approach is to develop better “lock-in” pixels for use in image sensor arrays. Lock-in pixels provide distance information indirectly, using the time-of-flight (TOF) principle. TOF systems determine the distance of an object by shining light on it, reflecting that light to the pixel and noting when it arrives, and calculating the distance light would have traveled in that time. Artilux, Inc. researchers will report the first Ge-on-Si lock-in pixels for indirect TOF measurements for such uses. These Ge-on-Si pixels demonstrated both high sensitivity (quantum efficiency >85% and >46% at 940nm/1550nm wavelengths, respectively) and high resolution (demodulation contrast >0.81 at 300MHz), a significant improvement from their pure Si pixel counterparts. The technology may open new routes to high-performance indirect TOF sensors and imagers, as well as the potential adoption of eye-safe lasers for consumer electronics. The researchers say the lock-in pixels were fabricated using a commercially available foundry technology and hence may be ready for mass production in the near future."