SPAD imagers for remote sensing at the single-photon level

F. Villa; D. Bronzi; S. Bellisai; G. Boso; A. Bahgat Shehata; C. Scarcella; A. Tosi; F. Zappa; S. Tisa; D. Durini; S. Weyers; W. Brockherde

doi:10.1117/12.974532

19 November 2012 SPAD imagers for remote sensing at the single-photon level

F. Villa, D. Bronzi, S. Bellisai, G. Boso, A. Bahgat Shehata, C. Scarcella, A. Tosi, F. Zappa, S. Tisa, D. Durini, S. Weyers, W. Brockherde

Author Affiliations +

Proceedings Volume 8542, Electro-Optical Remote Sensing, Photonic Technologies, and Applications VI; 85420G (2012) https://doi.org/10.1117/12.974532
Event: SPIE Security + Defence, 2012, Edinburgh, United Kingdom

Abstract

Combined 2D imaging and 3D ranging sensors provide useful information for both long (some kms) and short (few tens of m) distance, in security applications. To this aim, we designed two different monolithic imagers in a 0.35 μm costeffective CMOS technology, based on Single Photon Avalanche Diodes (SPADs), for long-range time-of-flight (TOF) and short-range phase-resolved depth ranging. The single pixel consists of a SPAD (30 μm diameter), a quenching circuit, and a Time-to-Digital Converter (TDC) for TOF measurements or three up/down synched counters for phaseresolved depth assessments. Such smart pixels operate in two different modalities: single photon-counting for 2D “intensity” images; while either photon-timing or phase-resolved photon-counting for 3D “depth” images. In 2D imaging, each pixel has a counter that accumulates the number of photons detected by the SPAD in the pixel, thus providing single-photon level sensitivity and high (100 kframe/s) frame-rate. In the TOF 3D imager, each pixel measures the photon arrival time with a 312 ps resolution, thanks to a two-stage TDC (with 6 bit coarse counter plus a 4 bit fine interpolator), with a 320 ns full-scale range. The resulting spatial resolution is 9 cm within a 50 m range, centered at any user-selectable distance (e.g. 100 m – 5 km), with linearity of DNLrms=4.9% LSB and INLrms=11.7% LSB, and 175 ps precision. In the phase-resolved 3D imager, the in-pixel electronics measures the phase difference between the modulated light emitted by a laser and the back-reflected light, with both continuous-wave and pulsed-light modulation techniques.

Citation Download Citation

F. Villa, D. Bronzi, S. Bellisai, G. Boso, A. Bahgat Shehata, C. Scarcella, A. Tosi, F. Zappa, S. Tisa, D. Durini, S. Weyers, and W. Brockherde "SPAD imagers for remote sensing at the single-photon level", Proc. SPIE 8542, Electro-Optical Remote Sensing, Photonic Technologies, and Applications VI, 85420G (19 November 2012); https://doi.org/10.1117/12.974532

ACCESS THE FULL ARTICLE

INSTITUTIONAL
Select your institution to access the SPIE Digital Library.

SELECT YOUR INSTITUTION

PERSONAL
Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.

PERSONAL SIGN IN

No SPIE Account? Create one

PURCHASE THIS CONTENT

SUBSCRIBE TO DIGITAL LIBRARY

50 downloads per 1-year subscription

Members: $195

Non-members: $335 ADD TO CART

25 downloads per 1 - year subscription

Members: $145

Non-members: $250 ADD TO CART

PURCHASE SINGLE ARTICLE

Includes PDF, HTML & Video, when available