|Thesis abstract: |
Many social needs require the acquisition of images at very low light levels (e.g. no illumination), at high frame rates (possibly thousands of frames per second), and also with distance-resolution (possibly millimetre precision). Nowadays the imager market offers a broad portfolio of either commercial or scientific-grade cameras, ranging from consumer CMOS cameras up to high-end CCD imagers, but none of them simultaneously offers high speed and ultra-high sensitivity.
Single-Photon Avalanche Diode (SPAD) is the only viable detector that can fulfill all the previous requirements. Imagers based on SPADs can guarantee high sensitivity (even single photon sensitivity) together with high-frame rate. The chips based on SPAD arrays able not only to count single photons (¿single-photon counting¿) , but also to accurately tag them with their arrival time (¿single-photon timing¿) hence suitable to provide both intensity and distance information of the object under investigation.
Recently, SPADs were successfully implemented also in standard CMOS technologies that set the new state of art in terms of large active area and very low DCR and sharp timing precision. Such detectors will be the building block for SPAD smart pixels for advanced 2D and 3D imagers with single photon sensitivity and in-pixel processing. Thanks to CMOS SPAD, we could design, develop and fabricate photonic and microelectronic technologies for cost-effective manufacturing of very fast, highly sensitive, two-dimensional (2D) and three-dimensional (3D) SPAD cameras running at higher speed than standard video-rate.