ABSTRACT
In this Letter, a method for recovering homogeneous upconversion coefficients (HUCs) in Er(3+)-doped glasses and erbium-activated devices is illustrated. It is based on a particle swarm optimization (PSO) approach. The HUCs are calculated on the basis of known values of optical gain evaluated in different pumping conditions. The obtained numerical results proof that the proposed technique provides solutions that are very close to the expected values. Therefore the method constitutes a tool for the design and optimization of efficient rare-earth doped lasers and optical amplifiers. This approach can be considered a feasible and valid alternative method in the field of material science and optical engineering for determining HUCs and avoiding the employment of expensive equipment for the measurement of ion-ion interaction parameters.
ABSTRACT
This paper deals with design and refinement criteria of erbium doped hole-assisted optical fiber amplifiers for applications in the third band of fiber optical communication. The amplifier performance is simulated via a model which takes into account the ion population rate equations and the optical power propagation. The electromagnetic field profile of the propagating modes is carried out by a finite element method solver. The effects of the number of cladding air holes on the amplifier performance are investigated. To this aim, four different erbium doped hole-assisted lightguide fiber amplifiers having a different number of cladding air holes are designed and compared. The simulated optimal gain, optimal length, and optimal noise fig. are discussed. The numerical results highlight that, by increasing the number of air holes, the gain can be improved, thus obtaining a shorter amplifier length. For the erbium concentration NEr=1.8x1024 ions/m3, the optimal gain G(Lopt) increases up to ~2dB by increasing the number of the air holes from M=4 to M=10.
