Research on non-equal spaced optical phased array chip with

As a laser scanning technology, optical phased array (OPA) has the advantages of fast scanning speed, high accuracy, low loss, and easy integration, which has broad application prospects in optical communications, unmanned driving, laser radar, aerospace and other fields. In order to suppress the generation of side lobes, the operating wavelength is required to be greater than the OPA’s element spacing, which results in grating lobes inevitably generated near the main lobe of the far field, which reduces the scanning accuracy and scanning range of the OPA. A non-equal spacing OPA chip with grating lobe suppression function is proposed in this paper, which can achieve wide field of view and high-precision spot deflection. The genetic algorithm is used to optimize the array element spacing of 64 channels of non-equal spacing OPA to obtain the element distribution of the lowest grating lobe and achieve the best grating lobe suppression effect. The experimental results show that in the wavelength range of 1 500-1 600 nm, the optimized waveguide has a minimum spacing of 2.2 μm and a maximum spacing of 11.4 μm. The far-field spot of the chip can achieve a two-dimensional scanning angle of 20°×10°, and it has a significant inhibitory effect on side lobes.