Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Stable gain-switched thulium fiber laser with 140 nm tuning range   We demonstrate a gain-switched thulium fiber laser that can be continuously
tuned over 140 nm, while maintaining stable nanosecond single-pulse operation.
To the best of our knowledge, this system represents the broadest tuning range
for a gain-switched fiber laser. The system simplicity and wideband wavelength
tunability combined with the ability to control the temporal characteristics of
the gain-switched pulses mean this is a versatile source highly suited to a
wide range of applications in the eye-safe region of the infrared, including
spectroscopy, sensing and material processing, as well as being a practical
seed source for pumping nonlinear processes.

9
The categories of this paper are: nlin
29
The categories of this paper are: funct-an
30
The categories of this paper are: q-alg
33
The categories of this paper are: plasm-ph
6
The categories of this paper are: astro-ph
20
The categories of this paper are: acc-phys
5
The categories of this paper are: gr-qc
10
The categories of this paper are: q-bio
32
The categories of this paper are: atom-ph
2
The categories of this paper are: math
8
The categories of this paper are: hep-ex
14
The categories of this paper are: math-ph
28
The categories of this paper are: alg-geom
23
The categories of this paper are: solv-int
26
The categories of this paper are: bayes-an
16
The categories of this paper are: stat