A 72 × 60 Angle-Sensitive SPAD Imaging Array for Lens-less FLIM

Changhyuk Lee, Ben Johnson, TaeSung Jung, Alyosha Molnar
2016 Sensors  
We present a 72 × 60, angle-sensitive single photon avalanche diode (A-SPAD) array for lens-less 3D fluorescence lifetime imaging. An A-SPAD pixel consists of (1) a SPAD to provide precise photon arrival time where a time-resolved operation is utilized to avoid stimulus-induced saturation, and (2) integrated diffraction gratings on top of the SPAD to extract incident angles of the incoming light. The combination enables mapping of fluorescent sources with different lifetimes in 3D space down to
more » ... micrometer scale. Futhermore, the chip presented herein integrates pixel-level counters to reduce output data-rate and to enable a precise timing control. The array is implemented in standard 180 nm complementary metal-oxide-semiconductor (CMOS) technology and characterized without any post-processing.
doi:10.3390/s16091422 pmid:27598170 pmcid:PMC5038700 fatcat:dmqjx2oimjbt5bijvvryie462y