Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: In-vacuum scattered light reduction with cupric oxide surfaces for
  sensitive fluorescence detection   We demonstrate a simple and easy method for producing low-reflectivity
surfaces that are ultra-high vacuum compatible, may be baked to high
temperatures, and are easily applied even on complex surface geometries. Black
cupric oxide (CuO) surfaces are chemically grown in minutes on any copper
surface, allowing for low-cost, rapid prototyping and production. The
reflective properties are measured to be comparable to commercially available
products for creating optically black surfaces. We describe a vacuum apparatus
which uses multiple blackened copper surfaces for sensitive, low-background
detection of molecules using laser-induced fluorescence.

21
The categories of this paper are: adap-org
27
The categories of this paper are: comp-gas
9
The categories of this paper are: nlin
29
The categories of this paper are: funct-an
11
The categories of this paper are: hep-lat
28
The categories of this paper are: alg-geom
18
The categories of this paper are: econ
1
The categories of this paper are: cs
23
The categories of this paper are: solv-int
33
The categories of this paper are: plasm-ph
6
The categories of this paper are: astro-ph
20
The categories of this paper are: acc-phys
2
The categories of this paper are: math
32
The categories of this paper are: atom-ph
22
The categories of this paper are: chao-dyn
10
The categories of this paper are: q-bio