J.F. Massicott

Efficient, high-power, high-gain Er3+-doped silica fiber amplifier

We present results demonstrating that Er doped silica fibres may be operated as efficient high power oscillators and high gain power amplifiers in the 1i5um telecommunications window. Investigation of the saturation behaviour of a number of different fibre types is undertaken. The best of these provides 140mW of amplified output for a 1mW input signal at 1. SSpm pumped with 180mW at 1. 48pm. Pumping with higher powers at 980nm provides in excess of 500mW output for the same input signal power. Quantum efficiencies greater than 80 are achieved for both pump wavelengths. A 980nm contra-directionally pumped grating tuned oscillator is demonstrated giving a tunable output of over 250mW for lasing wavelengths between 1. 52jm and 1. S7jm and a launched power of 540mW. This represents an internal quantum efficiency in excess of 95. The results of two systems experiments utilising the power amplifiers are also presented. The first demonstrates a ten channel WDM network broadcasting to over 7 users111 and the second an unrepeatered 250km 2. 4Gbit/s transmission system12

Recent advances in silica fiber amplifiers at BT Laboratories

The erbium doped silica fibre amplifier has become almost universal in the 1.53-1.57?m band, due to its high gain and power handling, good linearity, and lack of crosstalk[1]. In this paper, we report results on amplification at wavelengths as long as 1.62?m in the erbium/silica system, greatly extending the existing gain window.