A Flexible 32x32 SPAD Image Sensor with Integrated Microlenses

The first single-photon avalanche diode (SPAD) image sensor fully integrated on flexible substrate is reported. The design consists of an array of 1024 quenched pixels with CMOS readout and addressing circuitries. The flexible substrate was made compatible with sol-gel polymer, which will be used to imprint microlenses by quartz mold to improve...