Time-of-flight Optical Ranging Sensor Based on a Current Assisted Photonic Demodulator

Time-of-flight Optical Ranging Sensor Based on a Current Assisted Photonic Demodulator ■

Daniël Van Nieuwenhove, Daniël Van Nieuwenhove, Daniël Van Nieuwenhove, Ward van der Tempel, Ward van der Tempel, Ward van der Tempel, Riemer Grootjans, Riemer Grootjans, Riemer Grootjans, Maarten Kuijk, Maarten Kuijk, Maarten Kuijk

Abstract ■

The presented optical ranging sensor utilizes a current assisted photonic demodulator (CAPD) in combination with an integrating circuit to measure time-of-flight. The distance information is obtained by correlating received modulated light with the sentout signal. Simulations and measurements show that the structure is suitable as a pixel in a real-time 3D-camera setup. A CMOS prototype is presented showing 0.25 A/W infrared photo-responsivity, nearly 100\% detector demodulation efficiency and good linearity. Different design aspects and possibilities are discussed and evaluated. With averaging, real time sub-cm resolution is achieved at a modulation speed of 20 MHz and using NIR 860 nm light.