Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Fabrication of polarization-independent waveguides deeply buried in
  crystal using aberration-corrected femtosecond laser direct writing   Writing optical waveguides with femtosecond laser pulses provides the
capability of forming three-dimensional photonic circuits for manipulating
light fields in both linear and nonlinear manners. To fully explore this
potential, large depths of the buried waveguides in transparent substrates are
often desirable to facilitate achieving vertical integration of waveguides in a
multi-layer configuration, which, however, is hampered by rapidly degraded
axial resolution caused by optical aberration. Here, we show that with the
correction of the spherical aberration, polarization-independent waveguides can
be inscribed in a nonlinear optical crystal lithium niobate (LN) at depths up
to 1.4 mm, which is more than one order of magnitude deeper than the waveguides
written with aberration uncorrected femtosecond laser pulses. Our technique is
beneficial for applications ranging from miniaturized nonlinear light sources
to quantum information processing.

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The categories of this paper are: hep-th
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The categories of this paper are: bayes-an
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The categories of this paper are: chao-dyn
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The categories of this paper are: gr-qc
9
The categories of this paper are: nlin
33
The categories of this paper are: plasm-ph
0
The categories of this paper are: hep-ph
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The categories of this paper are: hep-lat
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The categories of this paper are: math
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The categories of this paper are: hep-ex
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The categories of this paper are: quant-ph
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The categories of this paper are: dg-ga
32
The categories of this paper are: atom-ph
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The categories of this paper are: patt-sol
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The categories of this paper are: math-ph
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The categories of this paper are: acc-phys