Abstract
In this paper we present new infrared waveguides based on proton-exchanged Lithium Niobate samples. Characterization of the waveguides in the visible and near infrared allows to develop a wavelength dependence function for refractive index and birefringence that predicts a single mode behaviour at 4.7 μm. This was confirmed by Fourier Transform Spectroscopy and compared to beam propagation simulations. We have obtained the first single mode planar waveguide at 4.7 μm, based on a simple technique that could be interesting for developing integrated optics beam combiners for astronomy.
Acknowledgments
Authors would like to acknowledge the Institut National des Sciences de l'Univers (INSU-CNRS-France) for financial support given to this work. This work was also supported by the Ministerio de Educación y Ciencia (MEC-Spain) under grants MAT2005–06359-C03–01 and MAT2005–06359-C03–02. The authors would also like to thank Prof. J.M. Cabrera for fruitful discussions.