Broadband and Wavelength-Dependent Chalcogenide Optical Fiber Couplers

We present optical fiber couplers made of As
₂
Se
₃
glass. Broadband and wavelength-dependent couplers are fabricated from fibers of engineered core/cladding diameter ratios. Coupling ratios at the through-cross ports ranging from 50%-50% down to 1%-99% are achieved. The transparency of As
₂
Se
₃
glass over the spectral range of 1.5-12.0 μm makes it a material of prime interest for the fabrication of mid-infrared couplers.