Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Tunable mid-wave infrared Fabry-Perot bandpass filters using
  phase-change GeSbTe   We demonstrate spectrally-tunable Fabry-Perot bandpass filters operating
across the MWIR by utilizing the phase-change material GeSbTe (GST) as a
tunable cavity medium between two (Ge:Si) distributed Bragg reflectors. The
induced refractive index modulation of GST increases the cavity's optical path
length, red-shifting the passband. Our filters have spectral-tunability of ~300
nm, transmission efficiencies of 60-75% and narrowband FWHMs of 50-65 nm
(Q-factor ~70-90). We further show multispectral thermal imaging and gas
sensing. By matching the filter's initial passband to a CO$_{2}$
vibrational-absorption mode (~4.25 $\mu$m), tunable atmospheric CO$_{2}$
sensing and dynamic plume visualization of added CO$_{2}$ is realized.

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The categories of this paper are: adap-org
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The categories of this paper are: acc-phys
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The categories of this paper are: cs
35
The categories of this paper are: mtrl-th
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The categories of this paper are: dg-ga
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The categories of this paper are: chem-ph
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The categories of this paper are: q-alg
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The categories of this paper are: supr-con
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The categories of this paper are: gr-qc
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The categories of this paper are: econ
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The categories of this paper are: patt-sol
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The categories of this paper are: nlin
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The categories of this paper are: cmp-lg
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The categories of this paper are: hep-ph
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The categories of this paper are: eess
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The categories of this paper are: astro-ph