Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Few-mode fibers and AO-assisted high resolution spectroscopy: coupling
  efficiency and modal noise mitigation   NIRPS (Near Infra-Red Planet Searcher) is an AO-assisted and fiber-fed
spectrograph for high precision radial velocity measurements that will operate
in the YJH-bands. While using an AO system in such instrument is generally
considered to feed a single-mode fiber, NIRPS is following a different path by
using a small multi-mode fiber (more specifically called "few-mode fiber").
This choice offers an excellent trade-off by allowing to design a compact
cryogenic spectrograph, while maintaining a high coupling efficiency under bad
seeing conditions and for faint stars. The main drawback resides in a much more
important modal-noise, a problem that has to be tackled for allowing 1m/s
precision radial velocity measurements. We study the impact of using an AO
system to couple light into few-mode fibers. We focus on two aspects: the
coupling efficiency into few-mode fibers and the question of modal noise and
scrambling. We show first that NIRPS can reach coupling >= 50% up to magnitude
I=12, and offer a gain of 1-2 magnitudes over a single-mode solution. We
finally show that the best strategy to mitigate modal noise with the AO system
is among the simplest: a continuous tip-tilt scanning of the fiber core.

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The categories of this paper are: funct-an
4
The categories of this paper are: cond-mat
1
The categories of this paper are: cs
23
The categories of this paper are: solv-int
31
The categories of this paper are: ao-sci
13
The categories of this paper are: quant-ph
22
The categories of this paper are: chao-dyn
35
The categories of this paper are: mtrl-th
32
The categories of this paper are: atom-ph
30
The categories of this paper are: q-alg
10
The categories of this paper are: q-bio
25
The categories of this paper are: patt-sol
17
The categories of this paper are: q-fin
0
The categories of this paper are: hep-ph
34
The categories of this paper are: chem-ph
16
The categories of this paper are: stat