Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Generation of heralded single photons beyond 1100 nm by spontaneous
  four-wave mixing in a side-stressed femtosecond laser-written waveguide   We demonstrate a monolithically integrable heralded photon source in a
femtosecond laser direct written glass waveguide. The generation of photon
pairs with a wide wavelength separation requires a concomitant large
birefringence in the normal dispersion regime. Here, by incorporation of
side-stress tracks, we produce a waveguide with a birefringence of
$1.64\times~10^{-4}$ and propagation loss as low as 0.21 dB/cm near 980~nm. We
measure photon pairs with 300~nm wavelength separation at an internal
generation rate exceeding $5.05\times10^6$/s. The second order correlations
indicate that the generated photon pairs are in a strongly non-classical
regime.

35
The categories of this paper are: mtrl-th
28
The categories of this paper are: alg-geom
6
The categories of this paper are: astro-ph
4
The categories of this paper are: cond-mat
8
The categories of this paper are: hep-ex
24
The categories of this paper are: dg-ga
31
The categories of this paper are: ao-sci
9
The categories of this paper are: nlin
34
The categories of this paper are: chem-ph
5
The categories of this paper are: gr-qc
36
The categories of this paper are: cmp-lg
1
The categories of this paper are: cs
17
The categories of this paper are: q-fin
23
The categories of this paper are: solv-int
37
The categories of this paper are: supr-con
0
The categories of this paper are: hep-ph