Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Optically induced mode conversion in graded-index fibers using
  ultra-short laser pulses   We propose the use of graded-index few-mode fibers for mode-conversion by
long-period gratings (LPG) transiently written by ultrashort laser pulses using
the optical Kerr effect. The mode inter- action is studied by numerically
solving the multi-mode coupled nonlinear Schroedinger equations. We present
highly efficient conversion of the LP 01 - into the LP 11 -mode preserving the
pulse shape in contrast to previous results in step-index fibers. Furthermore,
mode conversion using different wavelengths for inducing and probing the LPG is
shown. Due to the flat phase-matching curve of the examined modes in the
graded-index fiber, mode-conversion can be observed for probe center
wavelengths of 1100nm up to 1800nm with a write beam centered around 1030nm.
Therefore, a complete separation of the probe from the write beam should be
possible as well as the application of optically induced guided mode conversion
for all optical modulation across a broad wavelength range.

33
The categories of this paper are: plasm-ph
26
The categories of this paper are: bayes-an
13
The categories of this paper are: quant-ph
2
The categories of this paper are: math
27
The categories of this paper are: comp-gas
20
The categories of this paper are: acc-phys
22
The categories of this paper are: chao-dyn
8
The categories of this paper are: hep-ex
12
The categories of this paper are: nucl-th
6
The categories of this paper are: astro-ph
18
The categories of this paper are: econ
21
The categories of this paper are: adap-org
29
The categories of this paper are: funct-an
16
The categories of this paper are: stat
1
The categories of this paper are: cs
11
The categories of this paper are: hep-lat