Nearest neighbors phase control for optical phased array communications

Optical phased arrays for communication offer the promise of non-mechanical steering, aperture and power scaling, adaptive-optic correction, and modularity. Modularity provides inherent redundancy and reliability along with line replaceable manufacturing and assembly. Successful optical phased array architectures based on stochastic parallel gradient descent require sampling and focusing the array using large lenses. Here we demonstrate a tiled phase control architecture requiring one detector per array element in an in-line modular geometry, eliminating the need for a large focusing optic while allowing for arbitrary phase control and beam steering. This architecture holds promise for communication and other optical phased array applications.