Phased Weighted Method To Eliminate Grating-lobes Of Optical Phased Array

Optical phased array is widely accepted and applied in laser radar, laser scanning imaging field with the development of science and technology, with it's high resolution, fast scanning speed, low weight and cost-effective advantages. However, the existence of grating-lobe restrains the development of optical phased array technology severely. Owning to its existence, not only limit scanning area and distance, get lower accuracy, but also reduce energy utilization. So how to reduce and suppress grating-lobe has become one of the hottest research directions.Therefore, facing on these urgently problems, the author takes phase weighted method to research in how to reduce and suppress grating-lobe. Firstly, review the research dynamic in and abroad, list some classic models of optical phased array, discuss the common used suppression methods'advantages and disanvantages. Secondly, the principles of deflect beam of optical phased array are analyzed in details, from which verifies that phase weighted method can reduce and suppress grating-lobe is feasible in theory by adopting step coefficient functions strategy. Furthermore, according to phase weighted's theory, the author deduces the supressing formulars, basing on which, discussing the change of grating-lobe's suppressed efficiency and deflect of beam with different step coefficient functions, such as linear, trigonometry functions. Finally, the simulation software MATLAB is adopted to model how the optical phased array parameters'affect on main lobe, grating-lobe suppression as well as beam deflect.Research results show that, the new developed phase weighted method is really good to reduce and suppress grating-lobe. So this work not only enrich the theory of optical phased array technology, but also provide a strong support for its widely use in projects.