Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: "M\"obius" Microring Resonator   A new category of optical microring resonator, which is analogous to the
M\"obius strip, is proposed. The "M\"obius" microring resonator allows the
conversion between modes with different polarizations in the ring and light
must circulate two cycles to be converted back to the original polarization
status, which is similar to a M\"obius strip. This topology structure of
polarization leads to the free spectral range be half of that corresponds to
the cavity round trip. The eigenmodes of this microring are hybridizations of
different polarizations and the breaking of the rotation invariance of the ring
makes the transmission be related with the polarization of input light. Our
work opens the door towards the photonic devices with nontrivial mode topology
and provides a novel way to engineering photonic structures for fundamental
studies.

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The categories of this paper are: q-bio
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The categories of this paper are: solv-int
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The categories of this paper are: cond-mat
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The categories of this paper are: ao-sci
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The categories of this paper are: gr-qc
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The categories of this paper are: adap-org
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The categories of this paper are: supr-con
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The categories of this paper are: math-ph
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The categories of this paper are: hep-th
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The categories of this paper are: dg-ga
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The categories of this paper are: acc-phys
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The categories of this paper are: nucl-th
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The categories of this paper are: hep-lat
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The categories of this paper are: atom-ph
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The categories of this paper are: funct-an
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The categories of this paper are: nlin