Experimental determination of the optimum number of quantum wells in multiwell heterolasers with radiation leakage into a substrate

The dependence of the mode structure and threshold characteristics of laser diodes with significant ($\sim$ 94%) radiation leakage into a substrate on the number of quantum wells (QWs) in a laser-diode heterostructure has been studied. It is established that laser diodes with a small number of QWs generate on the fundamental waveguide mode. As the number of QWs increases, the first waveguide mode begins to dominate and the threshold current increases, which is probably related to a weak filling of central QWs with nonequilibrium carriers and increased losses of the fundamental mode.