  It has been recently demonstrated that integrated optics could enhance
accuracy, stability, and ease of use of stellar interferometry techniques. The
subject of this thesis is the study of an optical component based on singlemode
waveguides for the coherent recombining of optical beams coming from four
telescopes. Proposed architecture provides a simultaneous an instantaneous
measurement of complex visibility of interferometric signals of the six
possible pairs of telescopes. The component is optimized for achromatic
behaviour over the H spectral transparency band of atmosphere and integrates an
original achromatic phase shifter in order to obtain four phase quadrature
states of interferometric fringes. Optical characterisation results obtained on
devices realized by deposition and etching of silica layers on silicon
substrate confirm theoretical predictions et enabled the study of more complex
components at the heart of second generation instrumentation projects of the
VLTI (Very Large Telescope Interferometer) This study shows that proposed
architecture can be extended to J and K spectral bands, can be applied for the
recombination of beams coming from six and even eight telescopes and could also
be applied to realise a fringe tracker.
