Optical and luminescence properties of Co:AgCl0.2Br0.8 crystals and their potential applications as gain media for middle-infrared lasers

Abstract

Infrared absorption and luminescence emission of cobalt doped silver halide crystals were investigated at room temperature and at low temperatures. A broad absorption band was observed in the near-infrared (1.4–2.5 µm) and a broad emission band in the middle-infrared (3.5–5.2 µm). The emission lifetime varied between 1.73 ms at low temperatures and 5 µs at room temperature. Based on the measured parameters and theoretical calculations, we believe that there is an excellent chance that these crystals would lase in the mid-IR. Moreover, it would be possible to extrude fibers from the crystals and obtain mid-IR fiber lasers.

Broad Mid-Infrared Luminescence in a Metal–Organic Framework Glass

“…In comparison with other Mid-IR luminescent Co-doped materials, there are many crystals doped with Co that demonstrate Mid-IR emission such as mixed halides (AgCl x Br 1– x :Co (3.5–5.2 μm)), fluorides (MgF 2 :Co (1.6–2.1 μm)), and sulfides (ZnS:Co (2.5–4 μm)). 35,48−51 These Mid-IR luminescent crystals illustrate broad emission bands especially in case of Co-doped mixed halides and sulfides, which cover only about 1.7 μm or less of the Mid-IR range. However, the melt-quenched ZIF-62 glass containing Co ions is characterized by broad Mid-IR luminescence, which covers about 3.3 μm (i.e.…”

“…The observed high structural ordering around Co ions ZIF-62 glass as well as the coupling with rotational and other low energy vibration modes of the organic linkers may strongly suppress the rate of nonradiative relaxation process, allowing ZIF-62 glass containing Co ions to emit Mid-IR luminescence. − This may explain the detection of Mid-IR emission of ZIF-62 glass containing Co ions compared to any other glasses. In comparison with other Mid-IR luminescent Co-doped materials, there are many crystals doped with Co that demonstrate Mid-IR emission such as mixed halides (AgCl x Br 1– x :Co (3.5–5.2 μm)), fluorides (MgF 2 :Co (1.6–2.1 μm)), and sulfides (ZnS:Co (2.5–4 μm)). ,− These Mid-IR luminescent crystals illustrate broad emission bands especially in case of Co-doped mixed halides and sulfides, which cover only about 1.7 μm or less of the Mid-IR range. However, the melt-quenched ZIF-62 glass containing Co ions is characterized by broad Mid-IR luminescence, which covers about 3.3 μm (i.e.…”

Growth and characterization of nonlinear optical telluromolybdate CoTeMoO 6 single crystals

“…6). These bands -in a first approximation -can be ascribed to spin-allowed d-d transitions of Co 2 þ ions in octahedral crystal field of oxygen ligands [32][33][34]. The 4 T 1g (F)-4 T 2g (F) transition of the room temperature spectra corresponds to the absorption bands with absorbance maximum at 1623 nm (6160 cm À 1 ), the 4 T 1g (F)-4 A 2g (F) transition involves broadband absorption at 859 nm (11640 cm À 1 ) and the third 4 T 1g (F)-4 T 1g (P) transition gives rise to the prominent band in the visible region at 585 nm (17100 cm À 1 ).…”