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We present high-reflectivity substrate-transferred single-crystal GaAs/AlGaAs interference coatings at a center wavelength of 4.54 um with record-low excess optical loss below 10 parts per million. These high-performance mirrors are…

We designed, fabricated, and characterized the properties of a silicon-based vacuum window suitable for millimeter-wave astrophysical applications. The window, which has a diameter of 124 mm, optically active diameter of 68 mm, and…

Instrumentation and Methods for Astrophysics · Physics 2026-05-04 Ryota Takaku , Scott Cray , Kosuke Aizawa , Akira Endo , Shaul Hanany , Kenichi Karatsu , Jürgen Koch , Kuniaki Konishi , Tomotake Matsumura , Haruyuki Sakurai

PASCO scientific 012-05187C Precision Interferometer is used in Michelson mode to investigate wavelengths and refractive indices. From varying the distance of the movable mirror in the Michelson setup the wavelength of the HeNe laser beam…

Instrumentation and Detectors · Physics 2020-01-08 Kamyar Modjtahedzadeh

The next generation of IACT (Imaging Atmospheric Cherenkov Telescope) will explore the uppermost end of the VHE (Very High Energy) domain up to about few hundreds of TeV with unprecedented sensibility, angular resolution and imaging…

Substrate-transferred crystalline coatings have recently emerged as a groundbreaking new concept in optical interference coatings. Building upon our initial demonstration of this technology, we have now realized significant improvements in…

Over the last decade, the Imaging Air Cerenkov technique has proven itself to be an extremely powerful means to study very energetic gamma-radiation from a number of astrophysical sources in a regime which is not practically accessible to…

Astrophysics · Physics 2010-11-24 I. de la Calle Perez , S. D. Biller

We present a detailed thermal and structural analysis of a 2m class solar telescope mirror which is subjected to a varying heat load at an observatory site. A 3-dimensional heat transfer model of the mirror takes into account the heating…

Instrumentation and Methods for Astrophysics · Physics 2015-05-27 Ravinder K Banyal , B. Ravindra

NectarCAM is a camera developed to detect Cherenkov light between 80 GeV and 30 TeV. It will equip the medium-sized telescopes (MST) of the Cherenkov Telescope Array Observatory (CTAO). The camera comprises 265 modules, covering a field of…

Instrumentation and Methods for Astrophysics · Physics 2022-04-28 F. Bradascio

A new project is developed with the implementation of a relatively new method of studying the primary cosmic ray -- the registration of extensive air showers' optical Vavilov-Cherenkov radiation (Cherenkov light) reflected from the snow…

Instrumentation and Methods for Astrophysics · Physics 2020-12-30 D. Chernov , E. Bonvech , M. Finger , M. Finger , V. Galkin , V. Ivanov , D. Podgrudkov , T. Roganova , I. Vaiman

Reflective light concentrators with hexagonal entrance and exit apertures are frequently used at the focal plane of gamma-ray telescopes in order to reduce the size of the dead area caused by the geometries of the photodetectors, as well as…

Instrumentation and Methods for Astrophysics · Physics 2015-09-01 Akira Okumura , Sakiya Ono , Syunya Tanaka , Masaaki Hayashidad , Hideaki Katagiri , Tatsuo Yoshida

This paper reports the successful fabrication of silica aerogel Cherenkov radiators produced in the first batches from a 96-tile mass production performed using pin-drying technique in our laboratory. The aerogels are to be used in a…

Inverse scattering is the process of estimating the spatial distribution of the scattering potential of an object by measuring the scattered wavefields around it. In this paper, we consider reflection tomography of high contrast objects…

Signal Processing · Electrical Eng. & Systems 2020-12-17 Ajinkya Kadu , Hassan Mansour , Petros T. Boufounos

A 'knee-like' approximation of Cherenkov light Lateral Distribution Functions, which we developed earlier, now is used for the actual tasks of background rejection methods for high energy (tens and hundreds of TeV) gamma-ray astronomy. In…

Instrumentation and Methods for Astrophysics · Physics 2017-04-05 A. Sh. M. Elshoukrofy , E. B. Postnikov , L. G. Sveshnikova

The two MAGIC 17-m diameter Imaging Atmospheric Cherenkov Telescopes have been equipped to work also as an intensity interferometer with a deadtime-free, 4-channel, GPU-based, real-time correlator. Operating with baselines between approx.…

We present a conceptual design for the input optical system for a multi-object spectrometer operating at submillimeter wavelengths. The Mirror MOS is based on a sequence of mirrors that enables low-loss propagation of beams from selected…

Instrumentation and Methods for Astrophysics · Physics 2015-05-13 Paul F. Goldsmith , Michael Seiffert

Thermally induced fluctuations impose a fundamental limit on precision measurement. In optical interferometry, the current bounds of stability and sensitivity are dictated by the excess mechanical damping of the high-reflectivity coatings…

Optics · Physics 2014-04-17 Garrett D. Cole , Wei Zhang , Michael J. Martin , Jun Ye , Markus Aspelmeyer

The photo-thermal transfer function from absorbed power incident on a dielectric mirror to the effective mirror position is calculated using the coating design as input. The effect is found to change in amplitude and sign for frequencies…

Optics · Physics 2015-06-23 Stefan W. Ballmer

This paper presents the results of a Fresnel Interferometric Array testbed. This new concept of imager involves diffraction focussing by a thin foil, in which many thousands of punched subapertures form a pattern related to a Fresnel zone…

Astrophysics · Physics 2008-08-07 Denis Serre , Laurent Koechlin , Paul Deba

The anomalous achromatic mirror operating in near-IR and visible frequency range was designed using an array of metal-insulator-metal (MIM) resonators. An incident wave interacting with MIM resonator experiences phase shift that is equal to…

Mesoscale and Nanoscale Physics · Physics 2016-10-18 Andrei Nemilentsau , Tony Low

In the era of high-angular resolution astronomical instrumentation, where long and very long baseline interferometers (constituted by many, $\sim$ 20 or more, telescopes) are expected to work not only in the millimeter and submillimeter…

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