A 1.6-μm pumped 1.9-μm thulium-doped fluoride fiber laser and amplifier of very high efficiency

Near-infrared emissions and quantum efficiencies in Tm3+-doped heavy metal gallate glasses for S- and U-band amplifiers and 1.8μm infrared laser

“…Much work is in progress worldwide to develop compact infrared laser for application such as medicine, remote sensing and LIDAR [1][2][3][4]. Meanwhile, the optical telecommunication field has great interest in optical amplifier operating in S-and U-bands in order to increase the transmission capacity of optical fiber [5][6][7].…”

Approaching the Non-Linear Shannon Limit

“…Development of the necessary transponder and amplifier technology [e.g. 87,88] for operation in the mid-infrared region, accompanied by achievement of the predicted low loss performance around 1900 nm, should enable the development of long reach communication with information capacities above 10 b/s/Hz. The overall capacity of the fibre will of course be restricted by the wavelength range over which the fibre wave-guiding is effective.…”

Multi-mode 2 μm Tm-silica fibre lasers with 1.61 μm in-band pumping

“…In-band pumping of the Tm-silica fibre beyond $1.56 mm gives both emission as well as absorption at the pump wavelength. In theory the optimum inversion occurs at the point where the difference between the absorption and emission crosssections, a and e , is a maximum [4]. It was found that a / e $ 8.6 in Tm-silica at 1.61 mm, which is much lower than the a / e $ 23 at 1.57 mm, as e is increased from 1.56 mm as figure 1 indicates [7].…”

“…An 80 mW output amplified spontaneous emission (ASE) source operating $2 mm with FWHM ($70 nm) and slope efficiency up to 14% from Tm-silica fibre has been achieved by in-band pumping at 1.61 mm [1]. The Tm-fluoride fibre has been pumped with semiconductor lasers at 1.57 mm (FWHM $ 12 nm) [2], 1.58 mm [3] and 1.63 mm (FWHM $ 12 nm) [2] and at 1.64 mm generated from a colour centre laser (FWHM $ 0.1 nm) [4]. The slope efficiencies of these Tm-fluoride fibre lasers are generally high (70% to 84%).…”