V-groove side-pumped 1.5μm fibre amplifier

A side-pumping technique, using an imbedded v-groove is used to efficiently pump a double-clad Er/Yb doped fibre amplifier operating at 1.5 mu m and pumped at 0.98 mu m. A diode-to-fibre coupling efficiency of 76% was measured for a 100 mu m wide broad stripe laser diode and a fibre with a 50 x 120 mu m first cladding. A maximum output power of 185mW, and separately, a small signal gain of 35dB, are demonstrated.