We have been developing a terahertz camera based on antenna-coupled superconducting resonators, the so-called microwave kinetic inductance detectors (MKIDs), and a silicon lens array. The MKID consists of a coplanar waveguide coupled to a double slot antenna and is patterned on a high-quality aluminum film grown by molecular beam epitaxy. The camera is sensitive at frequencies of 200-240 GHz. Its bandwidth is limited by the impedance properties of the double slot antenna. The design, fabrication, and optical evaluations of the planar antennas and silicon lens arrays are presented in this paper. The MKID camera has been evaluated both in dark conditions and under optical radiation in a 0.1-K dilution refrigerator. The electrical noise equivalent power was around 5×10-18 W/√(Hz) in dark conditions and 4×10-16 W/√(Hz), which is much lower than the photon noise level, with the optical load. The optical efficiency of the camera was estimated by three independent methods, and the results were consistent with each other and equal to 20%-25% without an anti-reflection coating on the lens surface.

Optical Efficiencies of Lens-Antenna Coupled Kinetic Inductance Detectors at 220 GHz

The six-meter Atacama Cosmology Telescope (ACT) in Chile was built to measure the cosmic microwave background (CMB) at arcminute angular scales. We are building a new polarization sensitive receiver for ACT (ACTPol). ACTPol will characterize the gravitational lensing of the CMB and aims to constrain the sum of the neutrino masses with ~0.05 eV precision, the running of the spectral index of inflation-induced fluctuations, and the primordial helium abundance to better than 1%. Our observing fields will overlap with the SDSS BOSS survey at optical wavelengths, enabling a variety of cross-correlation science, including studies of the growth of cosmic structure from Sunyaev-Zel'dovich observations of clusters of galaxies as well as independent constraints on the sum of the neutrino masses. We describe the science objectives and the initial receiver design.

ACTPol: A polarization-sensitive receiver for the Atacama Cosmology Telescope

In an earlier paper, a new class of thin-shell cavities were proposed to evade the steep frequency scaling of conventional axion haloscopes. In this follow-up work, we see that a generalized conic geometry enables robust frequency-tuning for these large-volume cm-wave cavities. The frequency-defining dimension of a conic shell-cavity changes symmetrically and uniformly during tuning, maintaining a high axion coupling efficiency (the form factor) to an external solenoid field. It is further shown that such tunable geometry is not restricted to circular cones. A general prescription for arbitrary volume-filling conic shell-cavities is developed and direct solutions are obtained for the created numerical models. The largest of the realized designs is a meandering "brain" cavity that is tunable over a frequency range of 20%. The scan rate of this cavity is three orders of magnitude larger than that of a scaled cylindrical cavity used in the current generation experiments. The prospects for such a large improvement in the scan rate should motivate R & D efforts in fabrication and other implementation techniques. If these engineering challenges can be met, cavity-based axion haloscopes can stay competitive at frequencies higher than a few GHz. We propose an experimental configuration at 20 GHz (~ 80 $\mu$eV) using an array of brain cavities and compare it with other proposals for similar frequencies.

Symmetrically Tuned Large-Volume Conic Shell-Cavities for Axion Searches

http://inspirehep.net/record/1313295/files/10.1016_j.phpro.2012.02.476.pdf

Detectors for the South Pole Telescope

Next generation cosmic microwave background (CMB) polarization anisotropy measurements will feature focal
plane arrays with more than 600 millimeter-wave detectors. We make use of high-resolution photolithography
and wafer-scale etch tools to build planar arrays of corrugated platelet feeds in silicon with highly symmetric
beams, low cross-polarization and low side lobes. A compact Au-plated corrugated Si feed designed for 150 GHz
operation exhibited performance equivalent to that of electroformed feeds: ~ -0.2 dB insertion loss, < -20 dB
return loss from 120 GHz to 170 GHz, < -25 dB side lobes and < -23 dB cross-polarization. We are currently
fabricating a 50mm diameter array with 84 horns consisting of 33 Si platelets as a prototype for the SPTpol and
ACTpol telescopes. Our fabrication facilities permit arrays up to 150mm in diameter.

Corrugated silicon platelet feed horn array for CMB polarimetry at 150 GHz

We are developing monolithic arrays of corrugated feed horns fabricated in silicon for dual‐polarization single‐mode operation at 90, 145 and 220 GHz. The arrays consist of hundreds of platelet feed horns assembled from gold‐coated stacks of micro‐machined silicon wafers. As a first step, Au‐coated Si waveguides with a circular, corrugated cross section were fabricated; their attenuation was measured to be less than 0.15 dB/cm from 80 to 110 GHz at room temperature. To ease the manufacture of horn arrays, electrolytic deposition of Au on degenerate Si without a metal seed layer was demonstrated. An apparatus for measuring the radiation pattern, optical efficiency, and spectral band‐pass of prototype horns is described. Feed horn arrays made of silicon may find use in measurements of the polarization anisotropy of the cosmic microwave background radiation.

Progress Toward Corrugated Feed Horn Arrays in Silicon

Handle everyday research tasks with reliable, citation-backed results

Your personal Research Agent to handle research tasks with citation-backed results

Popular Tasks used by Researchers

How can I help with your research?

Meet SciSpace

Get more enhanced response by uploading the PDFs you want me to reference.

No relevant PDFs in your library

SciSpace is the AI research assistant for academics. Run systematic literature reviews on 280M+ papers, and write papers with cited sources. Trusted by 1M+ students, PhDs & researchers.

SciSpace | AI for Research

Analyze PDFs

Code & Manuscripts

Funding & Grants

Literature & Patents

Medical & Clinical Data

Systematic Review

Visualize & Present

Web & Data

Build a Google Scholar-like website for your research.

Build a website

Create charts and images for your research

Create a Chart

Write a paper for submission to a journal

Draft a manuscript

Patent Search

Design eye-catching scientific posters in minutes.

Scientific Poster Generation

Systematic Literature Review

One task is running at the moment. Your messages will be shown right after.

Drag and drop or click here to browse

Loved by <highlight>1 million+</highlight> researchers

Extract a list of specific topics and their sources from unstructured text

Topics

Compare and analyze relevant papers that matches with your search

Papers

Get insights from PDFs and bookmarked papers from your library

My library

Recent searches

Try searching for:

Catch AI-generated content in scholarly and non-scholarly content

{ai} Detector

Ai Writer

Get PDF Summaries, highlighted text explanations 

Chat with PDF

Effortlessly create in-text citations and bibliographies in APA and 2,500 other formats

Citation generator

Get explanations, summaries, and answers on academic papers

Ease up your research workflow with {scispace}'s cohort of exciting AI tools

Elevate your academic writing skills and convey your ideas the way you want

Paraphraser

Explore our range of reading and writing tools

Your file is being prepared and should be ready in a few minutes. If it's a large file, it might take a bit longer. You can close this window, and we'll email you the file when it's done.

You have reached a maximum limit of <strong>{limit}</strong> columns in the table. Remove at least <strong>1</strong> column to add or create another one.

H. M. Cho

Author Tools

Chat about Author

Papers

Progress Toward Corrugated Feed Horn Arrays in Silicon