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Diffraction effects of large segmented mirror gaps and secondary mirror support struts produce diffraction peaks or flares that are a detriment to exoplanet detection. In this paper we present detailed parametric diffraction analyses of an innovative “Pinwheel Pupil” segmented mirror concept utilizing curved segment gaps and secondary support struts that can potentially eliminate these diffraction flares that can obscure a faint exoplanet image. The resulting numerical diffraction performance predictions are quantitatively compared to that of both ideal monolithic circular pupils and classical annular pupils with straight secondary mirror struts. We utilize performance – based merit functions consisting of both radial and azimuthal profiles of the resulting telescope point spread function.

It is often thought that because of the very small solid angle subtended by the field-of-view of the coronagraph, scattered light from optical surfaces will have no effect on images recorded for terrestrial exoplanet spectroscopy. In this paper, we examine mirror surface scatter and particulate contamination scatter as sources of background light or noise signal in large aperture terrestrial exoplanet telescope/coronagraph systems. Scattered light control to one part in 10^(+10) or better is required for exoplanet exploration. We will discuss the optical fabrication tolerances necessary to minimize narrowangle forward scatter and their relative effects upon direct imaging coronagraph instruments used to characterize terrestrial exoplanets.

Diffraction effects of large segmented mirror gaps and secondary mirror support struts produce diffraction peaks or flares that are a detriment to exoplanet detection. In this paper we present a detailed diffraction analysis of innovative segmented mirror concepts utilizing curved segment gaps and secondary support struts that eliminate these diffraction spikes that can obscure the faint exoplanet image. The resulting diffraction performance will be quantitatively compared to that of both monolithic circular pupils and classical hexagonally segmented mirrors. We will utilize performance-based merit functions consisting of both radial and azimuthal profiles of the resulting telescope point spread function.

The Zwicky Transient Facility (ZTF) will be a major upgrade to the 48” Schmidt Camera at Palomar Observatory, which was initially commissioned in 1948. Although the optical design for ZTF is a relatively small part of the project, system requirements placed special constraints on the optical design. This paper presents the optical design for ZTF as well as the system requirements that drove the optical design.

Front converters for the iPhone 6, from six different vendors, are examined in detail. Telephoto, wide angle, and fisheye converters are examined. System performance is measured, and the measured lens designs are presented. Great variety is found in both design type and performance; little correlation is found between performance and design type.