Nicolas Bachelard, Jonathan Andreasen, Sylvain Gigan, Patrick Sebbah
Active control of the pump spatial profile is proposed to exercise control
over random laser emission. We demonstrate numerically the selection of any
desired lasing mode from the emission spectrum. An iterative optimization
method is employed, first in the regime of strong scattering where modes are
spatially localized and can be easily selected using local pumping. Remarkably,
this method works efficiently even in the weakly scattering regime, where
strong spatial overlap of the modes precludes spatial selectivity. A complex
optimized pump profile is found, which selects the desired lasing mode at the
expense of others, thus demonstrating the potential of pump shaping for robust
and controllable singlemode operation of a random laser.
View original:
http://arxiv.org/abs/1202.4404
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