OPTIMUM DESIGN OF ER3+ DOPED FLUORIDE FIBER AMPLIFIERS PUMPED AT 820 NM AND 1480 NM

The paper compares the properties of erbium doped fluoride fibre ampli fiers pumped at 820 nm and 1480 nm. The comparison is based on the res ults of computer analysis performed with the aid of a comprehensive la rge-signal numerical model which considers the LP01 and LP11 modes of pump wave in a step-index fibre. The model has been used to optimise t he active fibre parameters for maximum gain at small-signal operation. The optimum cutoff wavelength of the LP11 mode has been found to be 8 00 nm and 850 nm for the 820 nm and 1480 nm pump wavelengths, respecti vely.