A device forming a photonic phased array antenna includes a low-refractive dielectric substrate, a nano-structured thin film formed on the low-refractive dielectric structure, and a high-refractive semiconductor waveguide formed over the low-refractive dielectric substrate and configured to operate in a single mode in the nano-structured thin film, wherein an antenna radiating a phase-modulated light wave to a free space is miniaturized to concentrate a radiated beam of a phased array antenna and to widen a scanning range.