Pr³⁺/Er³⁺ Codoped Ge‐As‐Ga‐S Glasses as Dual‐Wavelength Fiber‐optic Amplifiers for 1.31 and 1.55 μm Windows

Abstract

Fluorescence emissions at both 1.31 and 1.55 m communication windows were observed from Pr 3؉ /Er 3؉ codoped Ge-AsGa-S glasses with a single wavelength pumping at 986 nm. The lifetime of the Er 3؉ : 4 I 11/2 level decreased as the Pr 3؉ concentration increased, and that of the Pr 3؉ : 1 G 4 level increased as the Er 3؉ concentration increased. Energy transfer from the Er 3؉ : 4 I 11/2 level to the Pr 3؉ : 1 G 4 level was responsible for emission of the 1.31 m fluorescence from the Pr 3؉ : 1 G 4 level. Ge-As-Ga-S glasses that have been doped with Pr 3؉ and Er 3؉ cations are promising amplifier materials for both 1.31 and 1.55 m communication windows.

Properties of Dy3+‐Doped Ge–As–Ga–Se Chalcogenide Glasses

“…As will be explained later, 6 F 11/2 6 H 9/2 → 6 H 15/2 is the so‐called hypersensitive transition, 23 and most sensitive to the local symmetry of glass structure and thus to glass composition, while the transition probabilities in Pr 3+ ‐ and/or Nd 3+ ‐doped glasses were reported to depend largely on Ω 6 2 . Therefore we focus our attention on the electron transition of Dy 3+ : 6 F 11/2 6 H 9/2 → 6 H 15/2 in terms of Judd–Ofelt analysis, which was done using the calculated oscillator strengths of glasses 6,11,24 . Both calculated Judd–Ofelt intensity parameters Ω t=2,4,6 and fluorescence parameters, including effective radiative probability A eff and branching ratio β, were summarized in Table II.…”

“…2 Therefore we focus our attention on the electron transition of Dy 31 : 6 F 11/2 6 H 9/2 -6 H 15/2 in terms of Judd-Ofelt analysis, which was done using the calculated oscillator strengths of glasses. 6,11,24 Both calculated Judd-Ofelt intensity parameters O t 5 2,4,6 and fluorescence parameters, including effective radiative probability A eff and branching ratio b, were summarized in Table II. Root-mean-square values of the fitting were in the range of 0.03-0.54 Â 10 À6 .…”

“…Although the 1.31 μm fluorescence of Pr 3+ ‐doped ChG glasses has been well investigated, 6,7 Dy 3+ ‐doped ChG glasses, which can also provide fluorescence in this waveband, have recently become a new focus due to advantages such as higher emission cross‐section and larger emission branching ratio 3,6,8,9 . In searching for perfect host composition that possesses large RE solubility, several authors have concentrated on Ge–Ga–S, 7 Ge–As–S, 10 Ge–Ga–As–S 11 systems, all focusing on sulfide‐based ChG glasses. Because selenide ChG glasses have higher refractive indices and lower vibrational phonon energies, we turned our attention to a family of Dy 3+ ‐doped Ge–Ga–Se ChG glasses 12 .…”

“…12 The purpose of the present work is to extend our investigation to the wider Ge-As-Ga-Se ChG glass compositions with the expectation that arsenic addition would enhance the tendency of the system to resist devitrification. 11,13 The particular significance of the present work is connected with considerations of optimizing both thermal and optical properties of glasses, which is scant 14 but very important for application of materials, for example, in minimizing the potential for devitrification during fiber fabrication.…”

Transparent chalcogenide glass-ceramics

“…By replacing erbium with other rare earths such as Tm 3+ (Dai et al, 2010) or by co-doping with two rare earths (Tm 3+ /Ho 3+ , Pr 3+ /Er 3+ ) (Hewak, 1998;Park et al, 2000;Li et al, 2011), these materials could be promising candidates for the making of new laser sources working in the second atmospheric window ranged between 2 and 5 mm. This work will now be extended to selenide-based glass-ceramics, as Hubert et al (2013) have demonstrated that the same phenomenon can be observed in selenide-based glass-ceramics doped with Er 3+ .…”