Abstract

Any designed two-layer antireflection coating with calculated phase thicknesses z and y of the first and second matching layers, respectively, always allows the following “looking-glass” transformation: z → 2π− z, y → 2π− y. In each of such solutions one of the layers is always thicker (and another thiner ) than quarter-wavelength. It is shown in Fig.1. The duality of solutions was exploited earlier for design of the integral multiple layers antireflection coatings transparent for two selected wavelengths λ₁ and λ₂[1]. Here we report application of such dual-band antireflection coatings for design of laser windows for second and higher harmonic generation, i.e. when the scaling parameter $\gamma =\frac{{\lambda }_2}{{\lambda }_1}$ should be selected as an integer as in case of the harmonic generations.

© 2001 Optical Society of America