Modeling of resonantly pumped mid-infrared Pr3+-doped chalcogenide fiber amplifier with different pumping schemes.

We propose a model for resonantly pumped Pr3+-doped chalcogenide fiber amplifiers, which includes excited state absorption and the full spectral amplified spontaneous emission spanning from 2 μm to 6 μm. Based on this model, the observed near- and mid-infrared photoluminescence generated from Pr3+-doped chalcogenide fiber is explained. Then the output properties of a 4.1 μm resonantly pumped Pr3+-doped chalcogenide fiber amplifier are simulated in both co- and counter-pumping schemes. Results show that the 4.1 μm counter-pumped fiber amplifier can achieve a power conversion efficiency (PCE) of over 62.8% for signal wavelengths ranging from 4.5 μm to 5.3 μm. This is, to our best knowledge, the highest simulated PCE for a Pr3+-doped chalcogenide fiber amplifier.