An optical characterization system utilizing a micro-lens array (MLA) is provided. The system may include an electron source and a MLA including a micro-deflection array (MDA). The MDA may include an insulator substrate and a plurality of hexapole electrostatic deflectors disposed on the insulator substrate. The MDA may further include a plurality of voltage connecting lines configured to electrically couple the plurality of hexapole electrostatic deflectors to one or more voltage sources. The MDA may be configured to split a primary electron beam from the electron source into a plurality of primary electron beamlets. The system may be configured to focus the plurality of primary electron beamlets at a wafer plane.