  Type-III-burst radio signals can be mimicked in the laboratory via
laser-plasma interaction. Instead of an electron beam generating Langmuir waves
(LW) in the interplanetary medium, the LWs are created by a laser interacting
with a millimeter-sized plasma through the stimulated Raman instability. In
both cases, the LWs feed the Langmuir decay instability which scatters them in
several directions. The resulting LWs may couple to form electromagnetic
emission at twice the plasma frequency, which has been detected in the
interplanetary medium, and recently in a laboratory laser experiment [Marqu\`es
et al. Phys. Rev. Lett. 124, 135001 (2020)]. This article presents the first
numerical analysis of this laser configuration using particle-in-cell
simulations, providing details on the wave spectra that are too difficult to
measure in experiments. The role of some parameters is addressed, with a focus
on laser intensity, in order to illustrate the behavior of the electromagnetic
emission's angular distribution and polarization.
