Experimental observation of gain in a resonantly pumped Pr3+-doped chalcogenide glass mid-infrared fibre amplifier notwithstanding the signal excited-state absorption

Abstract

We demonstrate a maximum gain of 4.6 dB at a signal wavelength of 5.28 μm in a 4.1 μm resonantly pumped Pr 3+ -doped selenide-based chalcogenide glass fibre amplifier of length 109 mm, as well as a new signal excited-stated absorption (ESA) at signal wavelengths around 5.5 μm. This work to the best of our knowledge is the first experimental demonstration of gain at mid-infrared (MIR) wavelengths in a Pr 3+ -doped chalcogenide fibre amplifier. The signal ESA of the fibre is attributed to the transition 3 H 6 → ( 3 F 4 , 3 F 3 ) after the pump ESA ( 3 H 5 → 3 H 6 ) at a pump wavelength of 4.1 μm, which absorbs the MIR signal at wavelengths of 5.37, 5.51 and 5.57 μm, and so spoils the amplifier’s performance at these wavelengths. Thus, this signal ESA should be suppressed in a resonantly pumped Pr 3+ -doped selenide-based chalcogenide fibre amplifier.

Mid-infrared sources for biomedical applications based on chalcogenide glass fibres

“…The output of a 4.1 μm resonantly pumped Pr 3+ -doped chalcogenide fibre amplifier was simulated in both co-and counter-pumping schemes with results predicting that a 4.1 μm counter-pumped fibre 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 modelling work was followed by the experimental observation of gain in a resonantly pumped Pr 3+ -doped chalcogenide glass midinfrared fibre amplifier, notwithstanding the signal excited-state absorption [42]. A maximum gain of 4.6 dB at a signal wavelength of 5.28 μm was demonstrated in a 4.1 μm resonantly pumped Pr3+-doped selenide-based chalcogenide glass fibre amplifier of length 109 mm.…”