Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Beam quality measurement through off-axis optical vortex   One of the challenges for every optical system is preserving the quality of
the used beam, which may be significantly reduced, due to the low condition of
used optical elements or their misalignment. There are plenty of methods
focused on the correction of the final beam, depending on the used entire
optical system. The problem of efficient beam evaluation is just as important.
So far, most of the measurements, are based on visual inspection, which is not
always enough, especially when the high quality of the beam is required. Novel
approaches use structured light to increase beam sensitivity for any
imperfections. In this paper, we present an approach, which uses optical vortex
shifted off-axis for a beam quality measurement. It uses SLM as a vortex
generating element, which is shifted off-axis by proper hologram
transformation. Tracking of the vortex trajectory may provide information about
beam quality and aberration of an optical system. The new vortex localization
algorithm will be presented.

8
The categories of this paper are: hep-ex
18
The categories of this paper are: econ
32
The categories of this paper are: atom-ph
17
The categories of this paper are: q-fin
12
The categories of this paper are: nucl-th
5
The categories of this paper are: gr-qc
29
The categories of this paper are: funct-an
21
The categories of this paper are: adap-org
9
The categories of this paper are: nlin
11
The categories of this paper are: hep-lat
22
The categories of this paper are: chao-dyn
16
The categories of this paper are: stat
34
The categories of this paper are: chem-ph
37
The categories of this paper are: supr-con
13
The categories of this paper are: quant-ph
30
The categories of this paper are: q-alg