This letter proposes a novel SPAD-based pixel, designed for direct time-of-flight (dToF) imaging with in-pixel averaging, which provides a promising advancement in low-power and potentially high image resolution for outdoor applications. By utilizing a laser pulse and two orthogonal sinusoidal signals, the pixel averages out the detected ambient light while accumulating the laser pulse round-trip time. A prototype pixel array was fabricated using a 180 nm CMOS process, featuring a commercial SPAD cell. By characterizing one pixel and employing a 100 klux solar emulator as an ambient light source with a fixed 40 ambient-to-signal ratio (ASR) over a 360â—¦ phase shift, equivalent to 6 m detection range, the maximum detected accuracy error was 3.3 \%, with a 5 cm precision.
Morsy, A, Baijot, CMJ, Jegannathan, G, Lapauw, T, Van Den Dries, T & Kuijk, M 2024, 'An In-Pixel Ambient Suppression Method for Direct Time of Flight', IEEE Sensors Letters, vol. 8, no. 10, 5504404. https://doi.org/10.1109/LSENS.2024.3453038
Morsy, A., Baijot, C. M. J., Jegannathan, G., Lapauw, T., Van Den Dries, T., & Kuijk, M. (2024). An In-Pixel Ambient Suppression Method for Direct Time of Flight. IEEE Sensors Letters, 8(10), Article 5504404. https://doi.org/10.1109/LSENS.2024.3453038
@article{5de587c0e76d4fd0b6705183c959e380,
title = "An In-Pixel Ambient Suppression Method for Direct Time of Flight",
abstract = "This letter proposes a novel SPAD-based pixel, designed for direct time-of-flight (dToF) imaging with in-pixel averaging, which provides a promising advancement in low-power and potentially high image resolution for outdoor applications. By utilizing a laser pulse and two orthogonal sinusoidal signals, the pixel averages out the detected ambient light while accumulating the laser pulse round-trip time. A prototype pixel array was fabricated using a 180 nm CMOS process, featuring a commercial SPAD cell. By characterizing one pixel and employing a 100 klux solar emulator as an ambient light source with a fixed 40 ambient-to-signal ratio (ASR) over a 360â—¦ phase shift, equivalent to 6 m detection range, the maximum detected accuracy error was 3.3 \%, with a 5 cm precision.",
keywords = "Single-photon avalanche diodes, Laser pulses, Switches, Sensors, Capacitors, Photonics, Accuracy, Time of flight, Optoelectronics",
author = "Ayman Morsy and Baijot, \{C{\'e}dric Martin J\} and Gobinath Jegannathan and Thomas Lapauw and \{Van Den Dries\}, Thomas and Maarten Kuijk",
note = "Funding Information: This work was mainly supported by Vrije Universiteit Brussel (VUB) through SRP 19 and SRP 78 grants. Publisher Copyright: {\textcopyright} 2017 IEEE.",
year = "2024",
month = sep,
day = "2",
doi = "10.1109/LSENS.2024.3453038",
language = "English",
volume = "8",
journal = "IEEE Sensors Letters",
issn = "2475-1472",
publisher = "IEEE",
number = "10",
}