Compensation and optimization of dispersion in nulling interferometry

The optical properties of materials are wavelength-dependent. This property, called dispersion, affects the performance of a wide-band nulling interferometer by inducing wavelength-dependent phase differences between the arms of the interferometer. In this paper, we analyze the influence of dispersion in nulling interferometers for exoplanet...

The role of amplitude, phase, polarization and their interconnection in nulling interferometry

Nulling interferometry is a promising technique to directly detect Earth-like exoplanets. Unfortunately, it is extremely challenging to build a nulling interferometer and to meet the requirements needed for Earth-like planet detection. In this, thesis, we analyze the role of amplitude, phase and polarization in nulling interferometry and we use...

Vectorial analysis of polarization issues in multi-axial nulling interferometers for exoplanet detection

We show the theoretical limitations of a multi-axial nulling interferometer with respect to longitudinal polarization. We furthermore analyze the filtering capabilities of a single-mode fiber in this case.

Design of a polarization nulling interferometer for exoplanet detection

We present the design of a new testbed experiment to demonstrate nulling interferometry using polarization properties. This three-beam set-up is perfectly symmetric with respect to the number of reflections and transmissions and should therefore allow a high rejection ratio in a wide spectral band.

Optimum synthetic-aperture imaging of extended astronomical objects

In optical aperture-synthesis imaging of stellar objects, different beam combination strategies are used and proposed. Coaxial Michelson interferometers are very common and a homothetic multiaxial interferometer is recently realized in the Large Binocular Telescope. Laboratory experiments have demonstrated the working principles of two new...

Nulling interferometry for exoplanet detection using polarization properties

We present a new type of nulling interferometer that makes use of polarization properties to have on-axis destructive interference. The proposed design, which only involves commercial components and no achromatic device, is also suitable for internal modulation. This type of interferometer should enable a high rejection ratio in a theoretically...

Nulling interferometry without achromatic phase shifters: Latest results

We discuss the previously-reported measurements of a three-beam nulling interferometer without achromatic phase-shifters, using delay lines only. The theoretical rejection ratio of a few thousand has not been achieved experimentally. In order to explain the obtained results, some direct spectral and polarization measurements have been performed....

Polarization nulling interferometry for exoplanet detection

We introduce a new concept of nulling interferometer without any achromatic device, using polarization properties of light. This type of interferometer should enable a high rejection ratio in a theoretically unlimited spectral band. We analyze several consequences of the proposed design, notably, the possibility of fast internal modulation.

Chromatism compensation in wide-band nulling interferometry for exoplanet detection

We introduce the concept of chromatism compensation in nulling interferometry that enables a high rejection ratio in a wide spectral band. Therefore the achromaticity condition considered in most nulling interferometers can be relaxed. We show that this chromatism compensation cannot be applied to a two-beam nulling interferometer, and we make...

Michelson wide-field stellar interferometry: Principles and experimental verification

A new interferometric technique for Michelson wide-field interferometry is presented that consists of a Michelson pupil-plane combination scheme in which a wide field of view can be achieved in one shot. This technique uses a stair-shaped mirror in the intermediate image plane of each telescope in the array, allowing for simultaneous correction...