[Zurück]

N. Bachelard, S. Burkhardt, M. Liertzer, S. Rotter, P. Sebbah:
"Selection and control of laser modes in random media through spatial pump modulation";
Vortrag: DPG Spring Meeting Berlin 2014, Berlin, Germany; 17.03.2014 - 21.03.2014.

Random lasers emit radiation typically at many different frequencies and in many different directions at once. Recent work has addressed the question how random lasers can be ``tamed" by making their emission spectrum and directionality externally tunable[1,2,3]. The key insight here is that this control can be conveniently exerted through the spatial profile of the pump beam that provides the external energy to the laser. Finding the optimal pump pattern, however, is difficult and requires an optimization procedure which does not give much insight into how a specific pump profile yields the desired laser emission. In this talk, I will elucidate the mechanisms behind the pump-control of random laser modes which is based on the spatial correlation between the applied pump profile and the lasing mode which it amplifies. Our findings are applicable not just to random lasers but for the design of lasers in general.

[1] N. Bachelard et al., Phys. Rev. Lett. 109, 033903 (2012).

[2] T. Hisch et al., Phys. Rev. Lett. 111, 023902 (2013)

[3] N. Bachelard et al.,arXiv:1303.1398 (2013)