Dual-wavelength coherent beam combination and wide-angle beam steering via integrated optical phased arrays

Integrated optical phased arrays (OPAs), owing to their high integration level and wide-angle beam-steering capability, are a key promising component for 3D/4D sensing and free-space optical communication. However, integrated OPAs typically employ a single-wavelength laser as the input light source, which limits their application in spectral imaging and secure communication. In this work, we propose and experimentally demonstrate a dual-wavelength coherent beam combining (CBC) scheme using a 64-element integrated OPA. A multiwavelength CBC model is established and validated with two wavelength pairs (1545/1555 and 1535/1565 nm). Both simulation and experimental results confirm that the beam dispersion intensifies with the steering angle and wavelength separation. To overcome this inherent dispersion issue, we employ a stochastic parallel gradient descent algorithm with two avalanche photodiodes as feedback sensors, achieving an arbitrarily configurable angular separation between the two wavelength beams. Finally, we demonstrate the wide field of view beam-steering capability of the combined beam across a 60 deg (±30 deg) range. We provide a foundational framework for advancing multiwavelength OPA toward applications in spectral imaging and secure optical communications.