Analysis of laser speckle reduction utilizing microlens-array-based projection screen.

This paper focuses on the theoretical analyzation of laser speckle reduction by utilizing a microlens array (MLA). A theoretical model was established to describe the screen effect on speckle reduction, taking into account MLA cell size and on-screen projection/detection resolution area size. The relationship between the speckle contrast ratio (SCR) of a projection system and the cell size of an MLA was studied and investigated. A guideline for choosing an MLA that is able to suppress SCR below the threshold of human perception is proposed from the obtained results.