Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Nonlinear frequency conversion is controlled by vacuum fluctuations   Ever since the advent of nonlinear optics, the generation of light by
frequency-conversion is drawing continued attention, and leading to emerging
applications such as supercontinuum sources for ultra stable clocks and
advanced microscopy. A modern approach to frequency-conversion is to switch
light confined in micro- and nanocavity resonances to enable on-chip operation.
Supposedly, nonlinear frequency conversion in such confined media differs from
traditional non-linear optics in three key features regarding output spectrum,
frequency shift, and critical time scale. Therefore, we switch GaAs-AlAs
microcavities by the electronic Kerr effect, and study a range of quality
factors to bridge the confined and the traditional non-linear regimes. We
uncover the key role of the density of vacuum fluctuations, i.e., the local
density of optical states (LDOS) for newly generated frequencies, a concept
inspired by cavity quantum electrodynamics (cQED). As a result, we succeed to
establish a framework, which not only describes nonlinear optics both in
traditional bulk and in confined media but also opens a new control dimension
in changing the color of light.

33
The categories of this paper are: plasm-ph
35
The categories of this paper are: mtrl-th
36
The categories of this paper are: cmp-lg
14
The categories of this paper are: math-ph
2
The categories of this paper are: math
26
The categories of this paper are: bayes-an
22
The categories of this paper are: chao-dyn
20
The categories of this paper are: acc-phys
8
The categories of this paper are: hep-ex
6
The categories of this paper are: astro-ph
23
The categories of this paper are: solv-int
29
The categories of this paper are: funct-an
25
The categories of this paper are: patt-sol
30
The categories of this paper are: q-alg
24
The categories of this paper are: dg-ga
15
The categories of this paper are: nucl-ex