Grating lobes analysis based on blazed grating theory for liquid crystal optical-phased array

Abstract

The grating lobes of the liquid crystal optical-phased array (LCOPA)based on blazed grating theory is studied. Using the Fraunhoferpropagation principle, the analytical expressions of the far-fieldintensity distribution are derived. Subsequently, we can obtain both thelocations and the intensities of the grating lobes. The derivedanalytical functions that provide an insight into single-slitdiffraction and multislit interference effect on the grating lobes arediscussed. Utilizing the conventional microwave-phased array technique,the intensities of the grating lobes and the main lobe are almost thesame. Different from this, the derived analytical functions demonstratethat the intensities of the grating lobes are less than that of the mainlobe. The computer simulations and experiments show that the proposedmethod can correctly estimate the locations and the intensities of thegrating lobes for a LCOPA simultaneously. (C) The Authors. Published bySPIE under a Creative Commons Attribution 3.0 Unported License.Distribution or reproduction of this work in whole or in part requiresfull attribution of the original publication, including its DOI.