Beam deflection by an aperiodic binary diffraction grating

Abstract

In this article we investigate the beam deflection by a one-dimensional binary diffraction grating. We propose a simple theoretical expression that can be used to predict the beam deflection angle due to both periodic and aperiodic binary grating profiles. We show that the theoretically calculated beam deflection angles agree well with the experimentally obtained deflection angles for various grating patterns. Thus the expression can be used to precisely position the deflected beam at a predetermined location. Further, we show that the theoretical expression can be used to construct a map between the spatial frequency of the grating and the deflection angle which can be employed to deflect the beam at equal intervals by sequentially changing the spatial frequency in accordance with the map. We also demonstrate the superior beam repeatability of a binary grating based beam scanner.