Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Unified description of saturation and bistability of intersubband
  transitions in the weak and strong light-matter coupling regimes   We propose a unified description of intersubband absorption saturation for
quantum wells inserted in a resonator, both in the weak and strong light-matter
coupling regimes. We demonstrate how absorption saturation can be engineered.
In particular we show that the saturation intensity increases linearly with the
doping in the strong coupling regime, while it remains doping independent in
weak coupling. Hence, countering intuition, the most suitable region to exploit
low saturation intensities is not the ultra-strong coupling regime, but is
instead at the onset of the strong light-matter coupling. We further derive
explicit conditions for the emergence of bistability. This work sets the path
towards yet unexisting ultrafast mid-infrared semiconductor saturable
absorption mirrors (SESAMs) and bistable systems. As an example, we show how to
design a mid-infrared SESAM with a three orders of magnitude reduction in
saturation intensity, down to about 5 kW/cm2.

30
The categories of this paper are: q-alg
33
The categories of this paper are: plasm-ph
7
The categories of this paper are: hep-th
12
The categories of this paper are: nucl-th
32
The categories of this paper are: atom-ph
6
The categories of this paper are: astro-ph
28
The categories of this paper are: alg-geom
16
The categories of this paper are: stat
14
The categories of this paper are: math-ph
20
The categories of this paper are: acc-phys
24
The categories of this paper are: dg-ga
8
The categories of this paper are: hep-ex
13
The categories of this paper are: quant-ph
10
The categories of this paper are: q-bio
29
The categories of this paper are: funct-an
15
The categories of this paper are: nucl-ex