Sub-Wavelength Grating Induced Wavefront Aberrations: A Case Study

摘要

The on-axis wavefront aberrations of a one-dimensional sub-wavelength grating anti-reflection coating on a f/1.7 lens surface is dominated by defocus, astigmatism, and piston. The astigmatism is 0.02 waves and the magnitude of the piston approaches 1 wave peak-to-valley. The difference in aberrations between orthogonally polarized wavefronts, or the retardance aberration, shows 0.01 waves of astigmatism like variation and more than 0.01 waves of retardance induced defocus like variation.