Dual-axis beam-steering optical–phased array with purely passive phase shifters

We present a multilayer optical-phased array (OPA) on a silicon-on-insulator (SOI) platform for dual-axis beam steering via wavelength tuning. By eliminating grating couplers, the proposed design significantly reduces substrate leakage and enhances energy efficiency. Passive phase shifters using delay lines both within and among layers enable precise phase control for efficient two-dimensional steering. The architecture incorporates a non-uniform emitter arrangement within each layer to suppress side-lobe levels, combined with a uniform arrangement between layers to simplify fabrication. In addition, edge emission minimizes diffraction and leakage, improving output efficiency. Numerical simulations validate the design, demonstrating a wide field of view with steering ranges of 120 deg horizontally and 60 deg vertically. This compact and scalable solution provides a high-performance approach for advanced photonic applications.