Articles techniques et présentations

We present an optimization procedure to improve the propagation properties of the depressed-cladding, buried micro-structured waveguides formed in a z-cut lithium niobate (LN) crystal by high repetition rate femtosecond (fs) laser writing. It is shown that the propagation wavelength for which the confinement losses of ordinary (O) and extraordinary ordinary (E) polarizations are below 1 dB/cm can be optimized beyond 3 micro meter for hexagonal WG structures with seven rings of tracks. Such an optimized structure is suitable for mid-infrared applications with a spectral region of propagation, where the confinement losses for O and polarization are below 1 dB/cm, up to 3.5 micro meter wavelength region.