Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Terahertz Pulse Shaping Using Diffractive Surfaces   Recent advances in deep learning have been providing non-intuitive solutions
to various inverse problems in optics. At the intersection of machine learning
and optics, diffractive networks merge wave-optics with deep learning to design
task-specific elements to all-optically perform various tasks such as object
classification and machine vision. Here, we present a diffractive network,
which is used to shape an arbitrary broadband pulse into a desired optical
waveform, forming a compact pulse engineering system. We experimentally
demonstrate the synthesis of square pulses with different temporal-widths by
manufacturing passive diffractive layers that collectively control both the
spectral amplitude and the phase of an input terahertz pulse. Our results
constitute the first demonstration of direct pulse shaping in terahertz
spectrum, where a complex-valued spectral modulation function directly acts on
terahertz frequencies. Furthermore, a Lego-like physical transfer learning
approach is presented to illustrate pulse-width tunability by replacing part of
an existing network with newly trained diffractive layers, demonstrating its
modularity. This learning-based diffractive pulse engineering framework can
find broad applications in e.g., communications, ultra-fast imaging and
spectroscopy.

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The categories of this paper are: nucl-th
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The categories of this paper are: gr-qc
33
The categories of this paper are: plasm-ph
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The categories of this paper are: cmp-lg
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The categories of this paper are: hep-lat
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The categories of this paper are: acc-phys
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The categories of this paper are: nlin
29
The categories of this paper are: funct-an
34
The categories of this paper are: chem-ph
30
The categories of this paper are: q-alg
10
The categories of this paper are: q-bio
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The categories of this paper are: q-fin
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The categories of this paper are: hep-ex
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The categories of this paper are: stat
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The categories of this paper are: astro-ph
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The categories of this paper are: bayes-an