The purpose of this paper is to review the recent progress in the developing smart pixel technologies. The paper begins by reviewing some of the rapidly evolving smart pixel terminologies. It then describes several of the smart pixel technologies that have recently emerged. Finally, it outlines the performance of these technologies in both device complexity and aggregate capacity. The reviewed SPA technologies include both the modulator-based FET-SEED, hybrid CMOS-SEED, and LCOS smart pixels and the source-based hybrid VCSEL/MSM, ELO, flip-chip-bonded VCSEL/MSM, and monolithic MSM/MESFET/VCSEL smart pixels
