Geometrical and physical optics analysis for mm-wavelength refractor telescopes designed to map the cosmic microwave background
arXiv:1911.13153 · doi:10.1364/AO.387842
Abstract
We present a compact two-lens HDPE f/1.6 refractor design that is capable of supporting a 28-deg diffraction-limited field of view at 1-mm wavelengths and contrast it to a similar two-lens refractor using silicon lenses. We compare the optical properties of these two systems as predicted by both geometrical and physical optics. The presented analysis suggests that by relaxing telecentricity requirements, a plastic two-lens refractor system can perform comparably to a similar silicon system across a wide field of view and wavelengths up to 1 mm. We show that for both telescope designs, cold stop spillover changes significantly across the field of view in a way that is somewhat inconsistent with Gaussian beam formalism and simple f-number scaling. We present results that highlight beam ellipticity dependence on both pixel location and pixel aperture size --- an effect that is challenging to reproduce in standard geometrical optics. We show that a silicon refractor design suffers from larger cross-polarization compared to the HDPE design. Our results address the limitations of solely relying on geometrical optics to assess relative performance of two optical systems. We discuss implications for future refractor designs.
15 pages, 17 figures
References in corpus (10)
- First M87 Event Horizon Telescope Results. I. The Shadow of the Supermassive Black Hole
- ACTPol: A polarization-sensitive receiver for the Atacama Cosmology Telescope
- Optical Design of the Atacama Cosmology Telescope and the Millimeter Bolometric Array Camera
- CMB Polarization Systematics Due to Beam Asymmetry: Impact on Inflationary Science
- BICEP3: a 95 GHz refracting telescope for degree-scale CMB polarization
- Design and performance of the Spider instrument
- Pre-flight integration and characterization of the SPIDER balloon-borne telescope
- Optical modeling and polarization calibration for CMB measurements with ACTPol and Advanced ACTPol
- PILOT: a balloon-borne experiment to measure the polarized FIR emission of dust grains in the interstellar medium
- Ray-tracing and physical-optics analysis of the aperture efficiency in a radio telescope