Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Single-Exciton Gain and Stimulated Emission across the Infrared Telecom
  Band from Robust Heavily-doped PbS Colloidal Quantum Dots   Materials with optical gain in the infrared are of paramount importance for
optical communications, medical diagnostics and silicon photonics. The current
technology is based either on costly III-V semiconductors that are not
monolithic to silicon CMOS technology or Er-doped fiber technology that does
not make use of the full fiber transparency window. Colloidal quantum dots
(CQD) offer a unique opportunity as an optical gain medium in view of their
tunable bandgap, solution processability and CMOS compatibility. The 8-fold
degeneracy of infrared CQDs based on Pb-chalcogenides has hindered the
demonstration of low-threshold optical gain and lasing, at room temperature. We
demonstrate room-temperature, infrared, size-tunable, band-edge stimulated
emission with linewidth of ~14 meV. Leveraging robust electronic doping and
charge-exciton interactions in PbS CQD thin films, we reach gain threshold at
the single exciton regime representing a four-fold reduction from the
theoretical limit of an eight-fold degenerate system, with a net modal gain in
excess of 100 cm-1.

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The categories of this paper are: plasm-ph
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The categories of this paper are: cmp-lg
10
The categories of this paper are: q-bio
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The categories of this paper are: chao-dyn
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The categories of this paper are: adap-org
30
The categories of this paper are: q-alg
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The categories of this paper are: eess
12
The categories of this paper are: nucl-th
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The categories of this paper are: supr-con
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The categories of this paper are: comp-gas
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The categories of this paper are: dg-ga
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The categories of this paper are: alg-geom
2
The categories of this paper are: math
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The categories of this paper are: q-fin
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The categories of this paper are: astro-ph
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The categories of this paper are: econ