Related papers: A new approach for the heliometric optics
Ellipsometry is a technique whereby the measurement of the two orthogonal polarization components of light reflected at glancing incidence allows a characterization of the optical properties of a material at a particular frequency.…
In 1911 Einstein proposed that light-bending by the Sun's gravitational field could be measured during a total solar eclipse. The first opportunity in which this measurement would be tried, was during the total solar eclipse of October 10,…
The Polarimetric and Helioseismic Imager (SO/PHI) onboard Solar Orbiter is a spectropolarimeter scanning the Fe I line at 617.3 nm, providing data of the solar photosphere. The same line is sampled by the Helioseismic and Magnetic Imager…
Polarization beam splitters, devices that separate the two orthogonal polarizations of light into different propagation directions, are one of the most ubiquitous optical elements. However, traditionally polarization splitters rely on bulky…
The Helioseismic Magnetic Imager (HMI) onboard the Solar Dynamics Observatory (SDO) records line-of-sight Dopplergram images of convective flows on the surface. These images are used to obtain the multi-scale convective spectrum. We design…
The 25.4m Giant Magellan Telescope (GMT) will be amongst the first in a new series of segmented extremely large telescopes (ELTs). The 25.4 m pupil is segmented into seven 8.4 m circular segments in a flower petal pattern. At the University…
The High Resolution Telescope (HRT) of the Polarimetric and Helioseismic Imager on board the Solar Orbiter spacecraft (SO/PHI) and the Helioseismic and Magnetic Imager (HMI) on board the Solar Dynamics Observatory (SDO) both infer the…
SOUTH POL will be a survey of the Southern sky in optical polarized light. It will use a newly designed polarimetric module at an 80cm Robotic Telescope. Telescope and polarimeter will be installed at CTIO, Chile, in late 2012. The initial…
We show that chirping gravitational waves in the LIGO frequency band $f=1 - 5000$ Hz can be gravitationally diffracted by the Sun, due to the coincidence of its Fresnel length $r_F \propto \sqrt{1\, {\rm AU}/f}$ and the solar radius…
Coronagraph instruments on future space telescopes will enable the direct detection and characterization of Earth-like exoplanets around Sun-like stars for the first time. The quest for the optimal optical coronagraph designs has made rapid…
Deflection of light by gravity was predicted by General Relativity and observationaly confirmed in 1919. In the following decades various aspects of the gravitational lens effect were explored theoretically, among them the possibility of…
The Simons Observatory is a ground-based telescope array located at an elevation of 5200 meters, in the Atacama Desert in Chile, designed to measure the temperature and polarization of the cosmic microwave background. It comprises four…
High cadence observations of solar activity (active regions, flares, filaments) in the H$\alpha$ line were performed at Meudon and Haute Provence Observatories from 1956 to 2004. More than 7 million images were recorded, mainly on 35 mm…
We demonstrate neutron beam focusing by axisymmetric mirror systems based on a pair of mirrors consisting of a confocal ellipsoid and hyperboloid. Such a system, known as a Wolter mirror configuration, is commonly used in x-ray telescopes.…
Gratings and holograms are patterned surfaces that tailor optical signals by diffraction. Despite their long history, variants with remarkable functionalities continue to be discovered. Further advances could exploit Fourier optics, which…
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…
Daily full-disk observations of the solar photosphere and chromosphere started at Meudon Observatory in 1908. After a review of the scientific context and the historical background, we describe the instrumental characteristics and…
Imaging Atmospheric Cherenkov Telescopes (IACTs) need imaging optics with large apertures to map the faint Cherenkov light emitted in extensive air showers onto their image sensors. Segmented reflectors fulfill these needs using mass…
A new three-dimensional model of the solar photosphere is presented in this paper and made publicly available to the community. This model has the peculiarity that it has been obtained by inverting spectro-polarimetric observations, rather…
A number of design options for image slicers for NGST and Gemini are being investigated. These image slicers are all of the focussing type and both refractive and reflective solutions are being explored. One such device, an image slicer…