Some recent advances in the two-dimensional multi-quantum-well (MQW) array devices and their applications are reviewed, focusing mainly on the exciton absorptive reflection switch (EARS). It is an optically controlled three-terminal structure based on a self-electrooptic effect device (SEED). Smart pixels enable all-optical switching and processing with a massive parallelism. EARS has good performance in terms of high contrast and optical gain. EARS can perform photonic processing such as all-optical bit pattern matching and waveform regeneration.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">></ETX>