Concentration effect on optical amplification characteristics of Er-doped silica single-mode fibers

Contributed Review: A review of the investigation of rare-earth dopant profiles in optical fibers

“…To date, some of the most important techniques employed to reveal the location of dopants in bulk samples such as fiber preforms are based on the use of methods that are commonly applied in the field of analytical chemistry and material science. These techniques include; secondary ion mass spectroscopy (SIMS), 9,17,22 inductively coupled plasma mass spectroscopy or inductively coupled plasma atomic emission spectroscopy, 17,18 and X-ray microprobe analysis. 11 In addition, the confinement of dopants in fiber preforms has been examined using the electron probe microanalysis (EPMA) method and its counterpart systems.…”

Monte Carlo simulations of homogeneous upconversion in erbium-doped silica glasses

“…The probability per time unit of upconversion between two Er ions excited to the manifold is (1) whereas the probability per time unit of migration from an Er ion excited to the manifold to an Er ion in the ground level is…”

“…For erbium-doped fiber amplifiers, a reduction in gain from 18.3 to 6.9 dB due to quenching is described in [1] for an Er concentration of 6.4 10 m . In erbium-doped silica waveguides for integrated optics, Er concentrations as high as 1.0-2.0 10 m (corresponding to 1.3-2.5 wt.% Er may be necessary to simultaneously ensure sufficient gain and compactness of the components [2], [3], and consequently, quenching is a very serious problem with such devices.…”

“…However, this classical quenching theory deals with donors and acceptors of distinct sorts and is-as will be demonstrated-not adequate for the treatment of self-quenching in Er systems. 1 In the literature on high-concentration Er -doped devices, homogeneous upconversion is often assumed to depend quadratically on the population of the level, i.e., the number of upconversion processes occurring per time and volume unit is written where is the population concentration of the manifold, and is an upconversion coefficient [3], [4], [6], [7], [18], [22]. The equivalent average quenching rate experienced by an Er ion in the manifold is .…”

“…2) The electric dipole-dipole approximation and hence (1) and (2) the energy-transfer probabilities (electric dipole-dipole, magnetic dipole-dipole, electric dipole-quadrupole, and exchange interaction) seems unresolved [26], it is common within the treatment of energy-transfer between rare-earth ions to assume the electric dipole-dipole interaction to dominate [5], [14], [18], [27]. 3) Due to the short lifetimes of the manifolds and only the ground level and the upper laser level are assumed populated.…”