Experimental analysis of mode-hopping in bulk semiconductor lasers

In this work we experimentally study modehopping in bulk semiconductor lasers. This stochastic process is ruled by Kramers statistics with a decay rate depending on the laser parameters of the temperature of the substrate and the pumping current. For a general combination of these parameters the average residence times in the two active modes are not equal, resulting in an asymmetric probability distribution for the modal intensities. We show that, by choosing an appropriate path in the parameter space, we can vary the residence times of the two modes while holding their ratio constant. Along this path, the shape of modal intensities distributions are constant up to a scaling factor which is a function of the laser parameters. Then, the system can be described by a single Langevin equation. The effect of adding noise to the pumping current is also investigated.