Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Picosecond pulse-shaping for strong three-dimensional field-free
  alignment of generic asymmetric-top molecules   Fixing molecules in space is a crucial step for the imaging of molecular
structure and dynamics. Here, we demonstrate three-dimensional (3D) field-free
alignment of the prototypical asymmetric top molecule indole using elliptically
polarized, shaped, off-resonant laser pulses. A truncated laser pulse is
produced using a combination of extreme linear chirping and controlled phase
and amplitude shaping using a spatial-light-modulator (SLM) based pulse shaper
of a broadband laser pulse. The angular confinement is detected through
velocity-map imaging of H$^+$ and C$^{2+}$ fragments resulting from
strong-field ionization and Coulomb explosion of the aligned molecules by
intense femtosecond laser pulses. The achieved three-dimensional alignment is
characterized by comparing the result of ion-velocity-map measurements for
different alignment directions and for different times during and after the
alignment laser pulse to accurate computational results. The achieved strong
three-dimensional field-free alignment of $\langle \cos^{2}\delta \rangle=0.89$
demonstrates the feasibility of both, strong three-dimensional alignment of
generic complex molecules and its quantitative characterization.

14
The categories of this paper are: math-ph
33
The categories of this paper are: plasm-ph
8
The categories of this paper are: hep-ex
25
The categories of this paper are: patt-sol
18
The categories of this paper are: econ
24
The categories of this paper are: dg-ga
30
The categories of this paper are: q-alg
32
The categories of this paper are: atom-ph
31
The categories of this paper are: ao-sci
4
The categories of this paper are: cond-mat
16
The categories of this paper are: stat
13
The categories of this paper are: quant-ph
10
The categories of this paper are: q-bio
27
The categories of this paper are: comp-gas
35
The categories of this paper are: mtrl-th
17
The categories of this paper are: q-fin