Increased mode instability thresholds of fiber amplifiers by gain saturation

Abstract

We show by numerical modeling that saturation of the population inversion reduces the stimulated thermal Rayleigh gain relative to the laser gain in large mode area fiber amplifiers. We show how to exploit this effect to raise mode instability thresholds by a substantial factor. We also demonstrate that when suppression of stimulated Brillouin scattering and the population saturation effect are both taken into account, counter-pumped amplifiers have higher mode instability thresholds than co-pumped amplifiers for fully Yb${}^{3+}$ doped cores, and confined doping can further raise the thresholds.

13 pages, 8 figures

References in corpus (3)

• Steady-periodic method for modeling mode instability in fiber amplifiers
• Frequency dependence of mode coupling gain in Yb doped fiber amplifiers due to stimulated thermal Rayleigh scattering
• Spontaneous Rayleigh seeding of stimulated Rayleigh scattering in high power fiber amplifiers

Cited by in corpus (14)

• Transverse Mode Instability
• 1.3kW monolithic linearly-polarized single-mode MOPA and strategies for mitigating mode instabilities
• Mode instability thresholds for Tm-doped fiber amplifiers pumped at 790 nm
• Influence of core NA on Thermal-Induced Mode Instabilities in High Power Fiber Amplifiers
• Study of wavelength dependence of mode instability based on a semi-analytical model
• Influence of seed power on mode instabilities in high power fiber amplifiers
• Theory of Transverse Mode Instability in Fiber Amplifiers with Multimode Excitations
• Suppressing transverse mode instability through multimode excitation in a fiber amplifier
• Influence of signal bandwidth on mode instability threshold of fiber amplifiers
• Study of dopant concentrations on thermal induced mode instability in high power fiber amplifiers
• Maximizing the mode instability threshold of a fiber amplifier
• Characterization of Visible Range Gain in Praseodymium Doped Fiber Amplifier
• Increasing Modal Instabilities Threshold Through Bidirectional Pumping In High Power Fiber Amplifiers
• Polarization Effects on Thermal-Induced Mode Instabilities in High Power Fiber Lasers