Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Coherent control of optical activity and optical anisotropy of thin
  metamaterials   The future fibre optic communications network will rely on photons as
carriers of information, which may be stored in intensity, polarization or
phase of light. However, processing of such optical information usually relies
on electronics. Aiming to avoid the conversion between optical and electronic
signals, modulation of light with light based on optical nonlinearity has
become a major research field, but real integrated all-optical systems face
thermal management and energy challenges. On the other hand, it has recently
been demonstrated that the interaction of two coherent light beams on a thin,
lossy, linear material can lead to large and ultrafast intensity modulation at
arbitrarily low power resulting from coherent absorption. Here we demonstrate
that birefringence and optical activity (linear and circular birefringence and
dichroism) of functional materials can be coherently controlled by placing a
thin material slab into a standing wave formed by the signal and control waves.
Efficient control of the polarization azimuth and ellipticity of the signal
wave with the coherent control wave has been demonstrated in proof-of-principle
experiments in different chiral and anisotropic microwave metamaterials.

2
The categories of this paper are: math
25
The categories of this paper are: patt-sol
23
The categories of this paper are: solv-int
16
The categories of this paper are: stat
7
The categories of this paper are: hep-th
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The categories of this paper are: dg-ga
15
The categories of this paper are: nucl-ex
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The categories of this paper are: gr-qc
22
The categories of this paper are: chao-dyn
0
The categories of this paper are: hep-ph
28
The categories of this paper are: alg-geom
27
The categories of this paper are: comp-gas
12
The categories of this paper are: nucl-th
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The categories of this paper are: hep-ex
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The categories of this paper are: chem-ph
14
The categories of this paper are: math-ph