Highly birefringent chalcogenide optical fiber for polarization-maintaining in the 3-8.5 µm mid-IR window.

A highly birefringent polarization-maintaining chalcogenide microstructured optical fiber (MOF) covering the 3-8.5 µm wavelength range has been realized for the first time. The fiber cross-section consists of 3 rings of circular air holes with 2 larger holes adjacent to the core.