Ultrafast Laser Inscription of High Performance Mid-Infrared Waveguides in Chalcogenide Glass

We present the realization of mid-infrared waveguide by ultrafast laser inscription technique in a chalcogenide glass. Our approach is based on multicore waveguide that consists in an alignment on a mesh of positive refractive index channels placed parallel to each other. Two different meshes are investigated with different refractive index contrasts between the channel and the glass matrix. A detailed analysis of the performances at a wavelength of 4.5 $\mu$m shows propagation losses of 0.20 $\pm$ 0.05 dB/cm and coupling efficiencies higher than 60 %.