Efficiency and intensity distribution in a semiconductor laser operating in the ‘leaky’ regime

The differential efficiency is calculated for a semi-conductor laser having an optical waveguide with a wave leaking out into the substrate. The differential efficiency is shown to be close to the limit if the optical quality of the substrate (with losses ~1 cm^–1 or less) is sufficiently high and the remaining laser parameters have typical and attainable values. Optimisation of the parameters of such a laser makes it possible to increase the output power severalfold compared with the power of a laser generating a conventional waveguide mode without radiation leakage.