Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: A Fabry-Perot like two-photon interferometer for high-dimensional
  time-bin entanglement   We generate high-dimensional time-bin entanglement using a mode-locked laser
and analyze it with a 2-photon Fabry-Perot interferometer. The dimension of the
entangled state is limited only by the phase coherence between subsequent
pulses and is practically infinite. In our experiment a pico-second mode-locked
laser at 532 nm pumps a non-linear potassium niobate crystal to produce photon
pairs by spontaneous parametric down-conversion at 810 and 1550 nm.

2
The categories of this paper are: math
32
The categories of this paper are: atom-ph
8
The categories of this paper are: hep-ex
31
The categories of this paper are: ao-sci
34
The categories of this paper are: chem-ph
33
The categories of this paper are: plasm-ph
22
The categories of this paper are: chao-dyn
12
The categories of this paper are: nucl-th
36
The categories of this paper are: cmp-lg
3
The categories of this paper are: physics
4
The categories of this paper are: cond-mat
30
The categories of this paper are: q-alg
20
The categories of this paper are: acc-phys
26
The categories of this paper are: bayes-an
21
The categories of this paper are: adap-org
17
The categories of this paper are: q-fin