Pulse-Profile-Maintaining Characteristics of Gain-Switched Nanosecond Raman Fiber Laser and Amplifier

This paper investigates pulse-profile-maintaining characteristics of a gain-switched nanosecond Raman fiber laser (RFL) and its amplifier (RFA). It is found that the pulse profiles can be precisely maintained after conversion, only if pump repetition frequency (PRF) an integer multiple of, unit fraction or fractions fundamental cavity-defined PRF. The produced pulses are then amplified in RFA, also maintained. However, it further noticed detuning-induced defects they with itself. All these observed phenomena should originate from transient property gain, not involving any notable delaying saturation effects typically seen rare-earth-doped gain fibers. Our results demonstrate that, scale, Raman-converted well maintain profile shows strong resistance to detune between PRFs pulses. Benefiting we reasonably neglect depletion effect due walk-off various short regimes, which largely simplify design pulsed pumping sources.