Analysis and calculation of the fill factor for microlens array scanning systems.

Microlens array (MLA) scanning systems are used in numerous applications, such as laser radar and optical communications. Excrescent light generated by overlapping divergent beams from adjacent microlenses increases with scanning angle, thereby reducing the relative aperture and affecting the MLA system resolution. The fill factor is hence proposed to characterize the relative aperture, and its effects on the modulation transfer function are analyzed. The fill factor is calculated from matrix optics paraxial ray tracing using the system parameters. The simulated results of the MLA system and theoretical calculations are in good agreement. This work can benefit the design and evaluation of MLA systems.