Broadband mid-IR chalcogenide fiber couplers.

We demonstrate a broadband AsS-based fiber coupler operating up to the 5.4 μm wavelength range developed by using a fused biconical tapering technique. During the manufacturing process, real-time data monitoring of the coupling ratio was at 2.

Specifics of spectral loss measurement in infrared fibers.

Main error sources and their contribution to the total error of measuring the optical loss spectrum by the cut-back method are analyzed in the mid-IR range (2-20 μm) for multimode optical fibers made from materials with high (2-4) refractive index values. It is shown that in case of insufficient fiber length, neglecting the refractive index value leads to a systematic overestimation of the measured optical losses: the higher the refractive index of a fiber core material, the greater an overestimation. The main errors are typically introduced by a bad repeatability of preparation quality of fiber ends and a lower signal-to-noise ratio of mid-IR range experimental setups in comparison with the near-IR range.

Preparation and characterization of new glassy system As2P2S8-Ga2S3.

Glasses having the composition (100 - x)As2P2S8-xGa2S3 with x ranging from 0 to 50% were investigated to determine the compositional effect on properties and local structure. The glass transition temperature (Tg) and the stability parameter against crystallization (Tx - Tg) increased with the addition of Ga2S3. The structure of these glasses was probed by Raman scattering, Fourier transform infrared (FT-IR) and 31P nuclear magnetic resonance.