Isabelle Schanen

Fabrication and test of an integrated optical magic T on a glass substrate

In this work, we demonstrate the first implementation of an integrated optical magic T. Such structure is designed to give, at the output, the sum and the difference of its two input optical signals using the multimode interference phenomena. The structure is fabricated using the ionic exchange technology on glass. The first obtained results verify the function of the magic T.

MAFL experiment: development of photonic devices for a space-based multiaperture fiber-linked interferometer.

We present a three-telescope space-based interferometer prototype dedicated to high-resolution imaging. This project, named multiaperture fiber-linked interferometer (MAFL), was founded by the European Space Agency. The aim of the MAFL project is to propose, design, and implement for the first time to the best of our knowledge all the optical functions required for the global instrument on the same integrated optics (IO) component for controlling a three-arm interferometer and to obtain reliable science data. The coherent transport from telescopes to the IO component is achieved by means of highly birefringent optical fiber. The laboratory bench is presented, and the results are reported allowing us to validate the optical potentiality of the IO component in this frame. The validation measurements consist of the throughput of this optical device, the performances of metrological servoloop, and the instrumental contrasts and phase closure of the science fringes.

A starting point of an integrated optics concept for a space-based interferometer

This article deals with instrumentation challenges of the stellar interferometry mission IRSI-Darwin of the European Space Agency. The necessity to have a reliable and performant system for beam recombination has enlightened the advantages of an integrated optics solution, which is already in use for ground-base interferomety in the near infrared. However, since Darwin will operate in the mid infrared, this requires extending the integrated optics concept in this spectral range. This paper presents the guiding lines of the characterization work that should validate a new integrated optics concept for the mid infrared. We present also one example of characterization experiment we are working on.

Singlemode planar optics for thermal infrared wavelengths astronomical interferometry

Spatial filtering is a critical issue to achieve nulling interferometry in the framework of spatial missions aimed at the detection of exoplanets. Several working interferometric instruments take benefit of guided optics for spatial filtering in the near infrared wavelengths and thus provide accurate visibility measurements. Furthermore planar optics would also provide beam combining functions within a single compact and stable device. Existing telecom technology allows beam combiner manufacturing for 0.8-1.8 micrometers wavelengths. Adaptation of these technologies is required to cover the scientific domain of ground based interferometry in each atmospheric spectral band and of the spatial missions like IRSI/DARWIN and TPF dedicated to thermal infrared wavelengths [4-20 micrometers]. We present here some of the most promising materials and their associated technologies for the thermal infrared range. For each of these solutions, based on chalcogenide glasses, semiconductor materials and hollow waveguides, we present some manufactured components with their optical characterizations. We also present a method and test-benches to measure the single-mode wavelength range of waveguides.