Low-crosstalk wide-field-of-view optical phased array antenna based on a superlattice waveguide array

To address the issues of high inter-element crosstalk, limited scanning range, and large beam divergence in optical phased arrays, this work optimizes the antenna design based on coupled-mode theory. By introducing a propagation-constant mismatch between adjacent antennas, inter-element optical coupling is effectively suppressed, thereby reducing inter-element crosstalk, enabling a smaller antenna pitch, and expanding the transverse scanning range. In addition, an edge-etched grating antenna is selected because of its longer radiation length and higher upward-radiation efficiency, thereby increasing the effective aperture and reducing the beam divergence angle. The effects of the superlattice modulation strength and supercell element arrangement on crosstalk suppression are further investigated. Based on these design strategies, a 128-channel optical phased-array grating antenna based on a superlattice waveguide array is proposed. The device achieves a two-dimensional beam-scanning range of 101.60^∘×15.40^∘, with beam divergence angles of 0.62° and 1.20° in the transverse and elevation directions, respectively.