In recent years, freeform optical surfaces have been used increasingly in a variety of off-axis
reflective imaging systems with high performance levels. However, it is a difficult and …

A broadband antireflective subwavelength structure was developed suitable for large
diameter silicon or alumina lenses used in the optical systems of superconducting cameras …

The effect of aberrations on the aperture efficiency has not been discussed analytically,
though aberrations determine the performance of a wide field-of-view system. Expansion of …

Antenna efficiency is one of the most important figures of merit of a radio telescope for
observations, especially at millimeter wavelengths or shorter wavelengths, even for a …