Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Incident Direction Independent Wave Propagation and Unidirectional
  Lasing   We propose an incident direction independent wave propagation generated by
properly assembling different unidirectional destructive interferences (UDIs),
which is a consequence of the appropriate match between synthetic magnetic
fluxes and the incident wave vector. Single-direction lasing at spectral
singularity is feasible without introducing nonlinearity. UDI allows
unidirectional lasing and unidirectional perfect absorption; when they are
combined in a parity-time symmetric manner, the spectral singularities vanish
with bounded reflections and transmissions. Furthermore, the simultaneous
unidirectional lasing and perfect absorption for incidences from opposite
directions is created. Our findings provide insights into light control and may
shed light on the explorations of desirable functionality in fundamental
research and practical applications.

15
The categories of this paper are: nucl-ex
9
The categories of this paper are: nlin
6
The categories of this paper are: astro-ph
17
The categories of this paper are: q-fin
33
The categories of this paper are: plasm-ph
2
The categories of this paper are: math
21
The categories of this paper are: adap-org
29
The categories of this paper are: funct-an
24
The categories of this paper are: dg-ga
26
The categories of this paper are: bayes-an
28
The categories of this paper are: alg-geom
31
The categories of this paper are: ao-sci
7
The categories of this paper are: hep-th
25
The categories of this paper are: patt-sol
19
The categories of this paper are: eess
18
The categories of this paper are: econ