Fast and deterministic optical phased array calibration via pointwise optimisation

Owing to the structural errors in the optical phased array, an initial random phase reduces the quality of the deflection beam. The most commonly applied approach to phase calibration is based on adaptive optics. However, adaptive optimisation approaches have slow convergence and low diffraction efficiency. We proposed a pointwise optimisation approach to achieve fast and accurate beam deflection. This approach conducts phase calibration, combining global traversal and local searches individually for each array element. We built a phase-calibration optical system containing a one-dimensional optical waveguide phase array for further verification and designed the relevant mechanics. The simulation and experimental results demonstrate that the pointwise optimisation approach accelerates the calibration process and improves the diffraction efficiency.