Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Cavity attenuated phase shift Faraday rotation spectroscopy   Cavity attenuated phase shift Faraday rotation spectroscopy has been
developed and demonstrated by oxygen detection near 762 nm. The system
incorporates a high-finesse cavity together with phase-sensitive balanced
polarimetric detection for sensitivity enhancement and achieves a minimum
detectable polarization rotation angle (1{\sigma}) of $5.6\times 10^{-9}$
rad/$\surd$Hz, which corresponds to an absorption sensitivity of $4.5\times
10^{-10}$ cm$^{-1}/{\surd}$Hz without the need for high sampling rate data
acquisition.

1
The categories of this paper are: cs
32
The categories of this paper are: atom-ph
17
The categories of this paper are: q-fin
7
The categories of this paper are: hep-th
11
The categories of this paper are: hep-lat
10
The categories of this paper are: q-bio
18
The categories of this paper are: econ
4
The categories of this paper are: cond-mat
9
The categories of this paper are: nlin
15
The categories of this paper are: nucl-ex
19
The categories of this paper are: eess
6
The categories of this paper are: astro-ph
5
The categories of this paper are: gr-qc
21
The categories of this paper are: adap-org
30
The categories of this paper are: q-alg
25
The categories of this paper are: patt-sol