Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Multilayer black phosphorus as broadband saturable absorber for pulsed
  lasers from 1 to 2.7 {\mu}m wavelength   It attracts wide interest to seek universe saturable absorber covering
wavelengths from near infrared to mid-infrared band. Multilayer black
phosphorus, with variable direct bandgap (0.3-2 eV) depending on the layer
number, becomes a good alternative as a universe saturable absorber for pulsed
lasers. In this contribution, we first experimentally demonstrated broadband
saturable absorption of multilayer black phosphorus from 1 {\mu}m to 2.7 {\mu}m
wavelength. With the as-fabricated black phosphorus nanoflakes as saturable
absorber, stable Q-switching operation of bulk lasers at 1.03 {\mu}m, 1.93
{\mu}m, 2.72 {\mu}m were realized, respectively. In contrast with large-bandgap
semiconducting transition metal dichalcogenides, such as MoS2, MoSe2,
multilayer black phosphorus shows particular advantage at the long wavelength
regime thanks to its narrow direct bandgap. This work will open promising
optoelectronic applications of black phosphorus in mid-infrared spectral region
and further demonstrate that BP may fill the gap of between zero-bandgap
graphene and large-bandgap TMDs.

22
The categories of this paper are: chao-dyn
0
The categories of this paper are: hep-ph
28
The categories of this paper are: alg-geom
5
The categories of this paper are: gr-qc
31
The categories of this paper are: ao-sci
20
The categories of this paper are: acc-phys
19
The categories of this paper are: eess
13
The categories of this paper are: quant-ph
25
The categories of this paper are: patt-sol
26
The categories of this paper are: bayes-an
16
The categories of this paper are: stat
23
The categories of this paper are: solv-int
14
The categories of this paper are: math-ph
27
The categories of this paper are: comp-gas
30
The categories of this paper are: q-alg
33
The categories of this paper are: plasm-ph