Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Quantum noise of non-ideal Sagnac speed meter interferometer with
  asymmetries   The speed meter concept has been identified as a technique that can
potentially provide laser-interferometric measurements at a sensitivity level
which surpasses the Standard Quantum Limit (SQL) over a broad frequency range.
As with other sub-SQL measurement techniques, losses play a central role in
speed meter interferometers and they ultimately determine the quantum noise
limited sensitivity that can be achieved. So far in the literature, the quantum
noise limited sensitivity has only been derived for lossless or lossy cases
using certain approximations (for instance that the arm cavity round trip loss
is small compared to the arm cavity mirror transmission). In this article we
present a generalised, analytical treatment of losses in speed meters that
allows accurate calculation of the quantum noise limited sensitivity of Sagnac
speed meters with arm cavities. In addition, our analysis allows us to take
into account potential imperfections in the interferometer such as an
asymmetric beam splitter or differences of the reflectivities of the two arm
cavity input mirrors. Finally,we use the examples of the proof-of-concept
Sagnac speed meter currently under construction in Glasgow and a potential
implementation of a Sagnac speed meter in the Einstein Telescope (ET) to
illustrate how our findings affect Sagnac speed meters with meter- and
kilometre-long baselines.

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The categories of this paper are: gr-qc
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The categories of this paper are: ao-sci
36
The categories of this paper are: cmp-lg
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The categories of this paper are: physics
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The categories of this paper are: solv-int
35
The categories of this paper are: mtrl-th
32
The categories of this paper are: atom-ph
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The categories of this paper are: cond-mat
24
The categories of this paper are: dg-ga
21
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: hep-th
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The categories of this paper are: chao-dyn
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The categories of this paper are: astro-ph
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The categories of this paper are: nucl-ex
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The categories of this paper are: q-bio