79 research outputs found
Interferometer response characterization algorithm for multi-aperture Fabry-Perot imaging spectrometers
In recent years, the demand for hyperspectral imaging devices has grown
significantly, driven by their ability of capturing high-resolution spectral
information. Among the several possible optical designs for acquiring
hyperspectral images, there is a growing interest in interferometric spectral
imaging systems based on division of aperture. These systems have the advantage
of capturing snapshot acquisitions while maintaining a compact design. However,
they require a careful calibration to operate properly. In this work, we
present the interferometer response characterization algorithm (IRCA), a robust
three-step procedure designed to characterize the transmittance response of
multi-aperture imaging spectrometers based on the interferometry of
Fabry-Perot. Additionally, we propose a formulation of the image formation
model for such devices suitable to estimate the parameters of interest by
considering the model under various regimes of finesse. The proposed algorithm
processes the image output obtained from a set of monochromatic light sources
and refines the results using nonlinear regression after an ad-hoc
initialization. Through experimental analysis conducted on four different
prototypes from the Image SPectrometer On Chip (ImSPOC) family, we validate the
performance of our approach for characterization. The associated source code
for this paper is available at https://github.com/danaroth83/irca.Comment: 20 pages, 11 figures. (Revised structure, added experiments
VSI: a milli-arcsec spectro-imager for the VLTI
VLTi Spectro-Imager (VSI) is a proposition for a second generation VLTI
instrument which is aimed at providing the ESO community with the capability of
performing image synthesis at milli-arcsecond angular resolution. VSI provides
the VLTI with an instrument able to combine 4 telescopes in a baseline version
and optionally up to 6 telescopes in the near-infrared spectral domain with
moderate to high spectral resolution. The instrument contains its own fringe
tracker in order to relax the constraints onto the VLTI infrastructure. VSI
will do imaging at the milli-arcsecond scale with spectral resolution of: a)
the close environments of young stars probing the initial conditions for planet
formation; b) the surfaces of stars; c) the environment of evolved stars,
stellar remnants and stellar winds, and d) the central region of active
galactic nuclei and supermassive black holes. The science cases allowed us to
specify the astrophysical requirements of the instrument and to define the
necessary studies of the science group for phase A.Comment: 12 page
VITRUV - Imaging close environments of stars and galaxies with the VLTI at milli-arcsec resolution
The VITRUV project has the objective to deliver milli-arcsecond
spectro-images of the environment of compact sources like young stars, active
galaxies and evolved stars to the community. This instrument of the VLTI second
generation based on the integrated optics technology is able to combine from 4
to 8 beams from the VLT telescopes. Working primarily in the near infrared, it
will provide intermediate to high spectral resolutions and eventually
polarization analysis. This paper summarizes the result from the concept study
led within the Joint Research Activity advanced instruments of the OPTICON
program.Comment: In "The Power of Optical/IR Interferometry: Recent Scientific Results
and 2nd Generation VLTI Instrumentation", Allemagne (2005) in pres
Wavelength-scale stationary-wave integrated Fourier-transform spectrometry
Spectrometry is a general physical-analysis approach for investigating
light-matter interactions. However, the complex designs of existing
spectrometers render them resistant to simplification and miniaturization, both
of which are vital for applications in micro- and nanotechnology and which are
now undergoing intensive research. Stationary-wave integrated Fourier-transform
spectrometry (SWIFTS)-an approach based on direct intensity detection of a
standing wave resulting from either reflection (as in the principle of colour
photography by Gabriel Lippmann) or counterpropagative interference
phenomenon-is expected to be able to overcome this drawback. Here, we present a
SWIFTS-based spectrometer relying on an original optical near-field detection
method in which optical nanoprobes are used to sample directly the evanescent
standing wave in the waveguide. Combined with integrated optics, we report a
way of reducing the volume of the spectrometer to a few hundreds of cubic
wavelengths. This is the first attempt, using SWIFTS, to produce a very small
integrated one-dimensional spectrometer suitable for applications where
microspectrometers are essential
AMBER : a near infrared focal instrument for the VLTI
10 pagesInternational audienceAMBER is the General User near-infrared focal instrument of the Very Large Telescope interferometer. Its specifications are based on three key programs on Young Stellar Objects, Active Galactic Nuclei central regions, masses and spectra of hot Extra Solar Planets. It has an imaging capacity because it combines up to three beams and very high accuracy measurement are expected from the spatial filtering of beams by single mode fibers and the comparison of measurements made simultaneously in different spectral channels
MAORY for ELT: preliminary design overview
MAORY is one of the approved instruments for the European Extremely Large Telescope. It is an adaptive optics module, enabling high-angular resolution observations in the near infrared by real-time compensation of the wavefront distortions due to atmospheric turbulence and other disturbances such as wind action on the telescope. An overview of the instrument design is given in this paper
The MAORY first-light adaptive optics module for E-ELT
The MAORY adaptive optics module is part of the first light instrumentation suite for the E-ELT. The MAORY project phase B is going to start soon. This paper contains a system-level overview of the current instrument design
Application de l'interféromètre de Perot-Fabry à l'étude à grand champ de la galaxie et du Petit Nuage de Magellan. Développement d'un nouvel instrument : Pytheas
L'instrumentation Cigale basé sur un interféromètre de Perot-Fabry permet d'obtenir une spectroscopie de la raie H alpha dans un grand champ. Cette instrumentation est utilisée sur un petit télescope pour observer la galaxie et le Petit Nuage de Magellan pour comprendre leur structure tridimensionnelle. Nous présentons un multispectromètre a dispersion croisée permettant de couvrir le domaine spectral d'un réseau avec la grande résolution spectrale du Perot-Fabry, et ceci simultanément pour les différents points d'une source bidimensionnelle. Il est integral de champ (au sens de Courtes 1987), par la trame de lentilles qui permet d'isoler des points contigus d'une image. Il est multicanal, intégral spectral (au sens de Chabbal 1958), car il permet d'obtenir tous les éléments spectraux au cours du balayage pas à pas d'un seul ordre du Perot-Fabry. Pour 40 canaux de balayage, on obtient simultanément 400 spectres de résolution spectrale R30000 sur un domaine de 200 NM environ dans le visible pour un récepteur de 20002000 éléments.pas de résum
- …