Aperture Effects

This chapter discusses the effect of the finite aperture size on the measured wavefronts. Specifically, it discusses the aperture effect on the global tip/tilt and the higher‐order wavefront distortions. Z‐tilt definition is used to define the global tip/tilt. Transfer functions, relating the local deflection angle and the global tip/tilt, and the levels of the higher‐order wavefront distortions are derived and discussed for both one‐dimensional and circular apertures.