Design of ultra-wideband Yb:Er:Tm:Ho co-doped germanate glass devices

An Yb:Er:Tm:Ho co-doped germanate glass is considered to develop an exhaustive mathematical model of a 980-nm-pumped fiber laser enabling high efficient, multi-wavelength emission at 1550 nm, 1800 nm and 2050 nm. The model is based on the nonlinear rate equations and takes into account the different energy transfer phenomena between the rare earths. Several simulations are performed and the behavior of the device is investigated with respect to the laser cavity parameters, i.e. fiber length and output mirrors reflectivities. By employing an input pump power of 0.5 W, a fiber length of 30 cm and output mirrors reflectivities of 92%, 60% and 20%, three different laser signals with output powers of 36.9 mW, 39.4 mW and 35 mW at 1550 nm, 1800 nm and 2050 nm, respectively, are obtained. This simulation result promises optical sources allowing almost the same emission power at the three different wavelengths and/or a flat wideband amplification