Peter Amedzake

Mid-infrared (4.6μm) emission properties of Pr3+ doped KPb2Br5

The mid-infrared (MIR) emission from Pr-doped KPb2Br5 was investigated for possible applications in solid-state lasers. Under optical pumping at 1.55 and 1.907μm, Pr-doped KPb2Br5 exhibited a broad MIR emission centered at 4.6μm, with a bandwidth of 0.9μm at full width half maximum. The dominant contribution of the MIR emission was assigned to the H53→H43 transition of Pr3+ ions. The decay time of the H53 level was measured to be 26.5ms at room temperature and remained nearly unchanged when cooling the sample to 77K. Consistent with the energy-gap law, multiphonon emission quenching is expected to be small in Pr-doped KPb2Br5. A Judd-Ofelt analysis was performed and yielded a radiative lifetime of 40.7ms for the H53 level, which suggests a radiative quantum efficiency of ∼65%. The slightly reduced quantum efficiency is most likely due to residual impurities in the crystal providing nonradiative relaxation channels. The peak emission cross section for the 4.6μm emission was calculated to be ∼0.4×10−20cm2, ...

Materials Development for Mid-IR Solid-State Lasers

Solid-state lasers operating in the mid-IR wavelength region (3-5 mum) continue to be of great current interest for applications in laser remote sensing of chemical and biological agents, IR countermeasures, and bio-medical procedures. The development of mid-IR solid-state lasers based on oxide and fluoride crystals is hampered by large non-radiative decay rates through multi-phonon emission. On the contrary, rare earth (RE) doped crystals with low maximum phonon energies have shown efficient mid-IR emission as well as lasing at room temperature [1-9]. Examples of emission transitions in the 3-5 mum spectral region are indicated in Fig. 1 for the rare earth ions Pr3+, Nd3+, Dy3+ and Er3+.

Mid-infrared (3-5 μm) emission from rare earth doped KPb 2 Br 5

Solid-state lasers operating in the mid-infrared (MIR) wavelength region (3-5 μm) are of significant current interest for laser remote sensing of chemical and biological agents as well as for military countermeasures. The development of MIR solid-state lasers based on oxide and fluoride laser hosts is limited by non-radiative decay through multi-phonon relaxations. Rare earth doped crystals with low maximum phonon energies can exhibit efficient MIR emission at room temperature. In this paper, we present results of the material synthesis and optical properties of rare earth (Pr, Nd, Dy, Er) doped KPb2Br5, which has a maximum phonon energy of only ~140 cm-1.