5 µm CW Ce³⁺-doped chalcogenide glass fiber laser with 17% slope efficiency

Efficient room temperature mid-infrared laser action in a Ce³⁺-doped chalcogenide fiber was demonstrated. The fiber had a doped selenide glass core in an undoped sulfide glass cladding. The pump source was a CW Fe²⁺:ZnSe laser emitting at 4.14 µm. The optimized fiber length allowed obtaining up to 7 mW of 5.06 µm output with 17% slope efficiency at room temperature.