Abstract: The present invention provides, in at least one embodiment, a scheme which is effective in suppressing detrimental coherence effects such as random backscatter. In a fiber laser having a master oscillator power amplifier design, inserting a decorrelator in between the master oscillator and a first power amplifier or inserting a decorrelator in between the first power amplifier and a second power amplifier to reduce random backscatter, which allows for much more energy to be stored and higher gain without the risk of catastrophic optical damage, thus increasing the peak power that can be delivered as useful laser power. Backscattering can be further reduced by having the master oscillator depolarized, injection locked, and spectrally broadened to reduce the coherence length of the master oscillator.