Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Effects of four-wave-mixing in high-power Raman fiber amplifiers   In this work, we derive and present the coupled amplitude equations to
describe the evolutions of different spectral components in different
transverse modes for Raman fiber amplifiers (RFAs). Both the effects of the
four-wave-mixing in the fundamental mode (FM FWM) and the inter-modal
four-wave-mixing (IM FWM) on high-power RFAs are demonstrated through numerical
simulations. Specifically, effective FM FWM interactions could occur and lead
to a drop of the Raman threshold for RFAs by over 50%, despite that the
corresponding wave-vector mismatch is rather big. In addition, the IM FWM could
also impact the Raman threshold for RFAs with additional generation of the
first order Raman Stokes light in the higher-order mode. We also investigate
the effects of the intensity fluctuations in the initial inserted pump and seed
lasers on high-power RFAs. It reveals that the temporal stability of the
initial inserted pump laser have much more significant impacts on high-power
RFAs than that of the initial inserted seed laser. Notably, through applying
temporal stable laser as the initial inserted pump laser, both the FM FWM and
IM FWM effects could be effectively suppressed, and the Raman threshold for
high-power RFAs could be increased by over twice.

36
The categories of this paper are: cmp-lg
23
The categories of this paper are: solv-int
20
The categories of this paper are: acc-phys
12
The categories of this paper are: nucl-th
2
The categories of this paper are: math
27
The categories of this paper are: comp-gas
18
The categories of this paper are: econ
26
The categories of this paper are: bayes-an
5
The categories of this paper are: gr-qc
25
The categories of this paper are: patt-sol
10
The categories of this paper are: q-bio
24
The categories of this paper are: dg-ga
22
The categories of this paper are: chao-dyn
4
The categories of this paper are: cond-mat
32
The categories of this paper are: atom-ph
37
The categories of this paper are: supr-con