Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Linking the Quasi-Normal and Natural Modes of an open cavity   The present paper proposes a comparison between the extinction theorem and
the Sturm-Liouville theory approaches for calculating the e.m. field inside an
optical cavity. We discuss for the first time to the best of our knowledge, in
the framework of classical electrodynamics, a simple link between the Quasi
Normal Modes (QNMs) and the Natural Modes (NMs) for one-dimensional (1D),
two-sided, open cavities. The QNM eigenfrequencies and eigenfunctions are
calculated for a linear Fabry-Perot (FP) cavity. The first-order Born
approximation is applied to the same cavity in order to compare the first-order
Born approximated and the actual QNM eigenfunctions of the cavity. We
demonstrate that the first-order Born approximation for an FP cavity introduces
symmetry breaking: in fact, each Born approximated QNM eigenfunction produces
values below or above the actual QNM eigenfunction value on the terminal
surfaces of the same cavity. Consequently, the two error-functions for an
approximated QNM are not equal in proximity to the two terminal surfaces of the
cavity.

4
The categories of this paper are: cond-mat
26
The categories of this paper are: bayes-an
12
The categories of this paper are: nucl-th
13
The categories of this paper are: quant-ph
2
The categories of this paper are: math
35
The categories of this paper are: mtrl-th
37
The categories of this paper are: supr-con
32
The categories of this paper are: atom-ph
25
The categories of this paper are: patt-sol
22
The categories of this paper are: chao-dyn
36
The categories of this paper are: cmp-lg
7
The categories of this paper are: hep-th
6
The categories of this paper are: astro-ph
16
The categories of this paper are: stat
0
The categories of this paper are: hep-ph
30
The categories of this paper are: q-alg