Ultrahigh power diode-pumped 1.5-/spl mu/m fiber amplifiers

Summary form only given. In conclusion, we have achieved the highest output power 1.5-/spl mu/m Er,Yb-doped optical fiber amplifier output to date with no signs of saturation up to an output power of 4 W (+36 dBm). In addition we have shown that such an ultrahigh output amplifier can perform well in a digital systems test.