Pr/sup 3+/-doped fluoride fiber amplifier module pumped by a fiber coupled master oscillator/power amplifier laser diode

We constructed the first Pr/sup 3+/-doped fluoride fiber amplifier (PDFA) module pumped by a fiber-coupled master oscillator/power amplifier laser diode (MOPA-LD) operating at 1.017 μm. The maximum signal gain and noise figure were 30.5 and 5.5 dB, respectively. An output power of 18 dBm was achieved at an input signal power of 0 dBm. Furthermore, we showed that the use of MOPA-LD pumping, rather than conventional Nd-YLF laser pumping, makes it possible to halve the length of the Pr/sup 3+/-doped fluoride required in the amplifier module and also allows a broader spectral bandwidth to be achieved.