Two-color pump schemes for Er-doped tellurite fiber lasers and amplifiers at 2.7-2.8 mu m

摘要

We propose two-color pump schemes for CW Er-doped tellurite fiber lasers and amplifiers in the 2.7-2.8 mu m range at the I-4(11/2 )- I-4(13/2) transition. The use of the first pump wavelength of 0.98 mu m (I-4(15/2 )- I-4(11/2)) or 1.56 mu m (I-4(15/2) - I-4(13/2)) and the second pump wavelength of 1.7 mu m (I-4(13/2 -) I-4(9/2)) allows obtaining gain at relatively low powers. We have performed a theoretical study of laser operation under two-color pump on the basis of the experimentally measured parameters of the specially prepared Er-doped tellurite fiber from TeO2-ZnO-La2O3-Na2O glass. It has been shown numerically that, for an optimal fiber length, the small-signal gain may exceed 18 dB and laser generation may be achieved with a relatively low threshold of a few hundreds of mW and a maximum slope efficiency can be similar to 40%. In addition, we have demonstrated in experiment a prototype of the power-scalable Er silica fiber source generating simultaneously near 1.56 and 1.7 mu m, which may be used for implementing the proposed two-color pumped laser and amplifier.