The Stability Analysis for In-Band Pumped Master Oscillator Power Amplifiers

An analytical study is carried out for in-band-pumped ytterbium-doped fiber amplifiers. In particular, the high-brightness pump laser design criteria in terms of stability performance against the back reflections are discussed for different fiber and cavity parameters. The optimum condition for pump laser operations is emphasized considering optical peak efficiency and robustness. Furthermore, the boundary for the in-bandpumped power amplifier design describing output power characteristics and signal propagations along the fiber is discussed. The amplifier performance in terms of the optical efficiency and fiber length requirements are investigated, including all Raman interactions between pump signal and Stokes waves for different fiber types and for both copumping and counterpumping configurations.