Systems, methods, and other embodiments described herein relate to an antenna formed by a silicon photonic two-dimensional grating. In one embodiment, a phased-array light detection and ranging (LIDAR) device includes a phase shifting array that separately shifts a phase of a source light wave to produce separate light waves with distinct phases. The LIDAR device includes optical inputs operably connected with the phase shifting array to receive the separate light waves. The LIDAR device includes a photonic grating operably connected with the optical inputs to receive the separate light waves and having a body that is disposed within a substrate with a face of the body exposed within the substrate. The photonic grating including grating structures exposed within the face. The grating structures redirect the separate light waves to emit the light waves from the photonic grating to form the beam of light.