Related papers: Increasing Modal Instabilities Threshold Through B…
Fiber lasers are widely used in various fields owing to their high efficiency, flexible transmission and excellent beam quality. In applications such as industrial manufacturing and defense systems, a higher output power is always desired.…
When pulses propagate in gas-filled anti-resonant hollow-core fibers (AR-HCFs) modulational instability (MI) can lead to pulse break-up and loss of coherence. In pulse broadening and compression schemes, MI is a parasitic effect that…
We demonstrate how a narrowband pump and a broadband spectrum can be spatially multiplexed by selective coupling them in two distinct modes of a few-mode microstructure fiber. The first mode carries most of the input pump energy, and…
We show how signal linewidth affects the gain of stimulated thermal Rayleigh scattering (STRS) which is responsible for mode instability in fiber amplifiers. The gain is reduced if the coherence time of the signal is less than the group…
The stability of annular electromagnetic pumps (EMPs) is investigated through 3D direct numerical simulations. When induction effects dominate dissipative processes, linear induction EMPs become unstable and lead to non-axisymmetric states…
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…
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…
The paper describes a novel parametric excitation scheme that acts as a tunable amplifier by controlling two pumping signals and two nonlinear feedback terms. By modulating the stiffness of a mechanical oscillator with a digital signal…
Twin-beam coherence properties are analyzed both in the spatial and spectral domains at high-gain regime including pump depletion. The increase of the size of intensity auto- and cross-correlation areas at increasing pump power is replaced…
We investigate the dynamics of modulational instability (MI) in $\cal PT$-symmetric fiber Bragg gratings with a phenomenon of intermodulation known as four-wave mixing (FWM). Although the impact of FWM has already been analyzed in the…
We derive analytical expressions for the coherence in the onset of modulation instability, in excellent agreement with thorough numerical simulations. As usual, we start by a linear perturbation analysis, where broadband noise is added to a…
Breaking the symmetry in a coupled wave system can result in unusual amplification behavior. In the case of difference parametric amplification the resonant pump frequency is equal to the difference, instead of the sum, frequency of the…
We study the transverse mode instability (TMI) in the limit where a single higher-order mode (HOM) is present. We demonstrate that when the beat length between the fundamental mode and the HOM is small compared to the length scales on which…
We consider thermo-optic bistability in resonant excitation of high-quality modes in two-dimensional dielectric resonators. We develop a coupled-mode theory approach which account for the frequency shift due to a temperature dependent…
High gain parametric amplifier with a single-pass pulsed pump is known to generate broadband twin photon fields that are entangled in amplitude and phase but have complicated spectral correlation. Fortunately, they can be decomposed into…
Using the Bogoliubov transformation in multi-frequency modes to describe the evolution of the non-degenerate signal and idler twin beams, we theoretically investigate the quantum noise properties of the pulse pumped high gain fiber optical…
In this paper, we experimentally and theoretically show the improvement in noise characteristics in a distributed Raman amplifier (DRA) system for wavelength division multiplexing (WDM) transmission, utilizing our proposed pumping…
We develop a high-power narrow-linewidth fiber amplifier based on a tapered Yb-doped fiber. In the experiment, the narrow end of the tapered fiber is used as the input port of both pump source and signal light to form a robust all-fiber…
Amplification underlies the operation of many biological and engineering systems. Simple electrical, optical, and mechanical amplifiers are reciprocal: the backward coupling of the output to the input equals the forward coupling of the…
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,…