Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Thermally Induced Nonlinear Optical Absorption in Metamaterial Perfect
  Absorbers   A metamaterial perfect absorber consisting of a tri-layer (Al/ZnS/Al)
metal-dielectric-metal system with top aluminium nano-disks is fabricated by
laser-interference lithography and lift-off processing. The metamaterial
absorber had peak resonant absorbance at 1090 nm and showed nonlinear
absorption for 600ps laser pulses at 1064 nm wavelength. A nonlinear saturation
of reflectance was measured to be dependent on the average laser power incident
and not the peak laser intensity. The nonlinear behaviour is shown to arise
from the heating due to the absorbed radiation and photo-thermal changes in the
dielectric properties of aluminium. The metamaterial absorber is seen to be
damage resistant at large laser intensities of 25 MW/cm2.

19
The categories of this paper are: eess
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The categories of this paper are: dg-ga
28
The categories of this paper are: alg-geom
0
The categories of this paper are: hep-ph
9
The categories of this paper are: nlin
21
The categories of this paper are: adap-org
12
The categories of this paper are: nucl-th
27
The categories of this paper are: comp-gas
33
The categories of this paper are: plasm-ph
2
The categories of this paper are: math
25
The categories of this paper are: patt-sol
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The categories of this paper are: bayes-an
14
The categories of this paper are: math-ph
31
The categories of this paper are: ao-sci
20
The categories of this paper are: acc-phys
22
The categories of this paper are: chao-dyn