Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Multicore fibre technology - the road to multimode photonics   For the past forty years, optical fibres have found widespread use in
ground-based and space-based instruments. In most applications, these fibres
are used in conjunction with conventional optics to transport light. But
photonics offers a huge range of optical manipulations beyond light transport
that were rarely exploited before 2001. The fundamental obstacle to the broader
use of photonics is the difficulty of achieving photonic action in a multimode
fibre. The first step towards a general solution was the invention of the
photonic lantern (Leon-Saval, Birks & Bland-Hawthorn 2005) and the delivery of
high-efficiency devices (< 1 dB loss) five years on (Noordegraaf et al 2009).
Multicore fibres (MCF), used in conjunction with lanterns, are now enabling an
even bigger leap towards multimode photonics. Until recently, the single-moded
cores in MCFs were not sufficiently uniform to achieve telecom (SMF-28)
performance. Now that high-quality MCFs have been realized, we turn our
attention to printing complex functions (e.g. Bragg gratings for OH
suppression) into their N cores. Our first work in this direction used a
Mach-Zehnder interferometer (near-field phase mask) but this approach was only
adequate for N=7 MCFs as measured by the grating uniformity (Lindley et al
2014). We have now built a Sagnac interferometer that gives a three-fold
increase in the depth of field sufficient to print across N > 127 cores. We
achieved first light this year with our 500mW Sabre FRED laser. These are
sophisticated and complex interferometers. We report on our progress to date
and summarize our first-year goals which include multimode OH suppression
fibres for the Anglo-Australian Telescope/PRAXIS instrument and the Discovery
Channel Telescope/MOHSIS instrument under development at the University of
Maryland.

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The categories of this paper are: acc-phys
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The categories of this paper are: dg-ga
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The categories of this paper are: chao-dyn
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The categories of this paper are: quant-ph
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The categories of this paper are: gr-qc
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The categories of this paper are: bayes-an
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The categories of this paper are: funct-an
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The categories of this paper are: nucl-th
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The categories of this paper are: econ
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The categories of this paper are: math-ph
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The categories of this paper are: adap-org
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The categories of this paper are: ao-sci
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The categories of this paper are: q-bio
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The categories of this paper are: chem-ph
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The categories of this paper are: atom-ph
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The categories of this paper are: patt-sol