Novel multilevel phase kinoform

Abstract

Array generators are optical systems that split a single beam from a laser source into a one- or two- dimensional array of beams. Many different approaches for constructing array generators have been proposed recently. A Dammann grating is the transmission or reflection grating with binary phase levels and with different cell sizes in a period. The cell sizes in a period of the grating— called transition points—are determined by the design procedure so that the derived number of diffraction orders and desired intensity distribution in diffraction orders are obtained. Recently Turunen et al. proposed a new approach in design procedure of multilevel phase kinoform (MPK). The MPK is the transmission or reflection grating with multiphase levels and with the same cell size in a kinoform period. The phase levels of cells in a period of the grating are determined in the design procedure to have an array of diffraction orders with desired diffraction efficiency and intensity distribution. The MPK with multiphase levels determined by optimal design technique has a higher diffraction efficiency and lower reconstruction noise than does the Dammann grating with binary phase levels.