Improvement of high power operation in 9××nm broad area laser diodes

High power (over 30W) and high efficiency (69%) operation 9××-nm broad area laser diodes at CW are demonstrated by diode voltage reduction and widening strip width. For the purpose of output power maximization, power saturation phenomenon is experimentally investigated associating with junction temperature and near field. Power saturation is found to be governed by not only junction temperature but also by thermal lensing effect.