Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Polygonal vortex beams in quasi-frequency-degenerate states   We originally demonstrate the vortex beams with patterns of closed polygons
[namely polygonal vortex beams (PVBs)] generated by a
quasi-frequency-degenerate (QFD) Yb:CALGO laser resonator with astigmatic
transformation. The PVBs with peculiar patterns of triangular, square, and
parallelogram shapes carrying large orbital angular momentums (OAMs) are
theoretically investigated and experimentally obtained in the vicinity of the
SU(2) degenerate states of laser resonator. The PVBs in QFD states are compared
with the vortex beams with patterns of isolated spots arrays located on the
triangle-, square-, and parallelogram-shaped routes [namely
polygonalspots-array vortex beams (PSA-VBs)] under normal SU(2) degenerate
states. Beam profile shape of PVB or PSA-VB and OAM can be controlled by
adjusting the cavity length and the position of pump spot. The simulated and
experimental results validate the performance of our method to generate PVB,
which is of great potential for promoting novel technologies in particle
trapping and beam shaping.

13
The categories of this paper are: quant-ph
36
The categories of this paper are: cmp-lg
26
The categories of this paper are: bayes-an
23
The categories of this paper are: solv-int
27
The categories of this paper are: comp-gas
35
The categories of this paper are: mtrl-th
21
The categories of this paper are: adap-org
29
The categories of this paper are: funct-an
32
The categories of this paper are: atom-ph
11
The categories of this paper are: hep-lat
25
The categories of this paper are: patt-sol
22
The categories of this paper are: chao-dyn
10
The categories of this paper are: q-bio
12
The categories of this paper are: nucl-th
9
The categories of this paper are: nlin
19
The categories of this paper are: eess