Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Increasing two-photon entangled dimensions by shaping input beam
  profiles   Photon pair entangled in high dimensional orbital angular momentum (OAM)
degree of freedom (DOF) has been widely regarded as a possible source in
improving the capacity of quantum information processing. The need for the
generation of a high dimensional maximally entangled state in the OAM DOF is
therefore much desired. In this work, we demonstrate a simple method to
generate a broader and flatter OAM spectrum, i.e. a larger spiral bandwidth
(SB), of entangled photon pairs generated through spontaneous parametric
down-conversion by modifying the pump beam profile. By investigating both
experimentally and theoretically, we have found that an exponential pump
profile that is roughly the inverse of the mode profiles of the single-mode
fibers used for OAM detection will provide a much larger SB when compared to a
Gaussian shaped pump.

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The categories of this paper are: dg-ga
10
The categories of this paper are: q-bio
28
The categories of this paper are: alg-geom
17
The categories of this paper are: q-fin
27
The categories of this paper are: comp-gas
37
The categories of this paper are: supr-con
15
The categories of this paper are: nucl-ex
7
The categories of this paper are: hep-th
11
The categories of this paper are: hep-lat
18
The categories of this paper are: econ
20
The categories of this paper are: acc-phys
31
The categories of this paper are: ao-sci
16
The categories of this paper are: stat
21
The categories of this paper are: adap-org
23
The categories of this paper are: solv-int
14
The categories of this paper are: math-ph