Towards High-Order Diffraction Suppression Using Two-Dimensional Quasi-Periodic Gratings

Two-dimensional (2D) diffraction gratings are playing an increasingly important role in the optics community due to their promising dispersion properties in two perpendicular directions. However, conventional 2D diffraction gratings often suffer from wavelength overlapping caused by high-order diffractions, and producing diffraction gratings with nanometer feature size still remains a challenge. In recent years, 2D quasi-periodic diffraction gratings have emerged that seek to suppress high-order diffractions, and to be compatibility with silicon planar process. This chapter reviews the optical properties of 2D quasi-periodic gratings comprised of quasi-triangle array of holes, and details the effects of hole shape and location distribution on the high-order diffraction suppression. It is also discuss the feasibility of various nanofabrication techniques for high volume manufacturing 2D quasi-periodic gratings at the nanoscale.