Related papers: Modeled fiber amplifier performance near the mode …
We show by detailed numerical modeling that stimulated thermal Rayleigh scattering can account for the modal instability observed in high power fiber amplifiers. Our model illustrates how the instability threshold power can be maximized by…
In this letter, the impact of pump configuration on the modal instabilities (MI) threshold of high power fiber amplifiers is investigated. Using a time dependent computer model based on the optical beam propagation method (BPM), the effect…
We investigated the effct of pump wavelength on the modal instabilities (MI) in high power linearly-polarized Yb-doped fiber amplifiers. We built a novel semi-analytical model to determine the frequency coupling characteristics and power…
We use a detailed numerical model of stimulated thermal Rayleigh scattering to compute mode instability thresholds in Tm$^{3+}$-doped fiber amplifiers. The fiber amplifies 2040 nm light using a 790 nm pump. The cross-relaxation process is…
High-power fiber laser amplifiers have enabled an increasing range of applications in industry, medicine and defense. The power scaling for narrow-band amplifiers is currently limited by the transverse modal instability. Various techniques…
We present a detailed description of the methods used in our model of mode instability in high-power, rare earth-doped, large-mode-area fiber amplifiers. Our model assumes steady-periodic behavior, so it is appropriate to operation after…
We report on an accurate closed form analytical model for the gain of a Brillouin fiber amplifier that accounts for material loss in the depleted pump regime. We determined the operational model limits with respect to its relevant…
Dependence of mode instabilities (MI) on ytterbium dopant concentrations in high power fiber amplifiers has been investigated. It is theoretically shown that, by only varying the fiber length to maintain the same total small-signal pump…
A theoretical model is developed by exploiting the variational technique to investigate the evolution of an optical beam inside an optically pumped graded-index fiber amplifier. The variational analysis is a semi-analytical method that…
Multimode fibers have been proposed for mitigating nonlinear effects in high-power fiber amplifiers, allowing for significant power scaling. Most previous studies on light propagation in continuous-wave fiber amplifiers focus on single mode…
We present theoretical study of wavelength dependence of mode instability (MI) in high power fiber lasers, which employs an improved semi-analytical theoretical model. The influence of pump / seed wavelength and photodarkening on threshold…
Multimode fibers provide a promising platform for realizing high-power laser amplifiers with suppressed nonlinearities and instabilities. The potential degradation of optical beam quality has been a major concern for highly multimode fiber…
We revisit the problem of modulation instability (MI) in optical fibers, including higher-order dispersion terms, self-steepening, and Raman response. We derive expressions for the MI gain and use them to explore the role of self-steepening…
We report the experimental demonstration of modulation instability process assisted by a dispersion grating in an optical fiber. A simple analytical model is developed to further analyze and explain the complex dynamics of this process,…
We report on detailed in-situ distributed temperature measurements inside a high power fiber amplifier. The deducted thermal load and the TMI-threshold of a commercial LMA fiber with 25 micron core and 400 micron cladding was measured at…
We investigate multi-wave mixing associated with the strongly pump depleted regime of induced modulation instability (MI) in optical fibers. For a complete transfer of pump power into the sideband modes, we theoretically and experimentally…
Transverse Mode Instability (TMI) which results from dynamic nonlinear thermo-optical scattering is the primary limitation to power scaling in high-power fiber lasers and amplifiers. It has been proposed that TMI can be suppressed by…
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…
High-power single-frequency fiber amplifiers are increasingly dominant in technologies that require high optical power, stability, and coherence simultaneously. In this chapter, we first provide an overview of their key characteristics,…
The dynamics of the state of polarization in single mode and multimode fiber amplifiers are presented. The experimental results reveal that although the state of polarizations at the output can vary over a large range when changing the…