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

The 3D Spectroscopy for Adaptive Optics (Invited Talk)

International audienc

The 3D Spectroscopy for Adaptive Optics (Invited Talk)

International audienc