Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Designing double freeform surfaces for collimated beam shaping with
  optimal mass transportation and linear assignment problems   We propose a method for designing refractive optical elements for collimated
beam shaping. In this method, the problem of finding a ray mapping is
formulated as a linear assignment problem, which is a discrete version of the
corresponding mass transportation problem. A method for reconstructing optical
surfaces from a computed discrete ray mapping is proposed. The method is
suitable for designing continuous piecewise-smooth optical surfaces. The design
of refractive optical elements transforming beams with circular cross-section
to variously shaped (rectangular, triangular, and cross-shaped) beams with
plane wavefront is discussed. The presented numerical simulation results
confirm high efficiency of the designed optical elements.

5
The categories of this paper are: gr-qc
1
The categories of this paper are: cs
4
The categories of this paper are: cond-mat
12
The categories of this paper are: nucl-th
22
The categories of this paper are: chao-dyn
17
The categories of this paper are: q-fin
21
The categories of this paper are: adap-org
6
The categories of this paper are: astro-ph
37
The categories of this paper are: supr-con
19
The categories of this paper are: eess
20
The categories of this paper are: acc-phys
31
The categories of this paper are: ao-sci
34
The categories of this paper are: chem-ph
15
The categories of this paper are: nucl-ex
32
The categories of this paper are: atom-ph
28
The categories of this paper are: alg-geom