相关论文: A millimeter-wave antireflection coating for cryog…
The increasing scale of cryogenic detector arrays for sub-millimeter and millimeter wavelength astrophysics has led to the need for large aperture, high index of refraction, low loss, cryogenic refracting optics. Silicon with n = 3.4, low…
We present a broadband plasma spray anti-reflection (AR) coating technology for millimeter-wave astrophysics experiments with large-format, cryogenic optics. By plasma spraying alumina- and silica-based powders, we have produced coatings of…
We developed a broadband two-layer anti-reflection (AR) coating for use on a sapphire half-wave plate (HWP) and an alumina infrared (IR) filter for the cosmic microwave background (CMB) polarimetry. Measuring the faint CMB B-mode signals…
The desire for higher sensitivity has driven ground-based cosmic microwave background (CMB) experiments to employ ever larger focal planes, which in turn require larger reimaging optics. Practical limits to the maximum size of these optics…
Broadband refractive optics realized from high index materials provide compelling design solutions for the next generation of observatories for the Cosmic Microwave Background (CMB), and for sub-millimeter astronomy. In this paper, work is…
We have developed a novel two-layer anti-reflection (AR) coating method for large-diameter infrared (IR) filters made of alumina, for the use at cryogenic temperatures in millimeter wave measurements. Thermally- sprayed mullite and…
Refractive optical elements are widely used in millimeter and sub-millimeter astronomical telescopes. High resistivity silicon is an excellent material for dielectric lenses given its low loss-tangent, high thermal conductivity and high…
A broadband two-layer anti-reflection (AR) coating was developed for use on a sapphire half-wave plate (HWP) and an alumina infrared (IR) filter for cosmic microwave background (CMB) polarimetry. Measuring tiny CMB B-mode signals requires…
We demonstrate a silicon-based, single-layer anti-reflection coating that suppresses the reflectivity of metals at near-infrared frequencies, enabling optical probing of nano-scale structures embedded in highly reflective surroundings. Our…
We present two prescriptions for broadband (~77 - 252 GHz), millimeter-wave antireflection coatings for cryogenic, sintered polycrystalline aluminum oxide optics: one for large-format (700 mm diameter) planar and plano-convex elements, the…
Silicon optics with wide bandwidth anti-reflection (AR) coatings, made of multi-layer textured silicon surfaces, are developed for millimeter and submillimeter wavelengths. Single and double layer AR coatings were designed for an optimal…
We used two novel approaches to produce sub-wavelength structure (SWS) anti-reflection coatings (ARC) on silicon for the millimeter and sub-millimeter (MSM) wave band: picosecond laser ablation and dicing with beveled saws. We produced…
Future millimeter wavelength experiments aim to both increase aperture diameters and broaden bandwidths to increase the sensitivity of the receivers. These changes produce a challenging anti-reflection (AR) design problem for refracting and…
The Simons Observatory (SO) will be a cosmic microwave background (CMB) survey experiment with three small-aperture telescopes and one large-aperture telescope, which will observe from the Atacama Desert in Chile. In total, SO will field…
We present designs and fabrication of sub-wavelength anti-reflection (AR) structures on alumina for infrared absorptive filters with passbands near 30, 125, and 250 GHz. These bands are widely used by ground-based instruments measuring the…
We report on the first use of laser ablation to make sub-millimeter, broad-band, anti-reflection coatings (ARC) based on sub-wavelength structures (SWS) on alumina and sapphire. We used a 515 nm laser to produce pyramid-shaped structures…
We used laser ablation to fabricate sub-wavelength structure anti-reflection coating (SWS-ARC) on a 5 cm diameter alumina lens. With an aspect ratio of 2.5, the SWS-ARC are designed to give a broad-band low reflectance response between 110…
We have developed epoxy-based, broadband anti-reflection coatings for millimeter-wave astrophysics experiments with cryogenic optics. By using multiple-layer coatings where each layer steps in dielectric constant, we achieved low reflection…
Measuring the faint polarization signal of the cosmic microwave background (CMB) not only requires high optical throughput and instrument sensitivity but also control over systematic effects. Polarimetric cameras or receivers used in this…
Infrared (IR) blocking filters are crucial for controlling the radiative loading on cryogenic systems and for optimizing the sensitivity of bolometric detectors in the far-IR. We present a new IR filter approach based on a combination of…