COMPLETE-SINGLE-MODE OPERATION OF 180-DEGREES MODE PHASED-ARRAY LASERS BY IMPROVING TEMPERATURE DISTRIBUTION INSIDE THE STRIPE REGION

180 degrees mode phased array lasers with multiple stripes were system atically investigated for high-power, single lateral mode operation. P hased array lasers with a conventional loss guide structure were fabri cated for 180 degrees made operation because the structure allowed the threshold gain of 180 degrees mode to become smallest by introducing optical loss between stripes and outside the stripe region. It showed complete single lateral mode operation under pulsed condition. However , under continuous wave operation, phase-uncoupling occurred at the ed ge emitters as a result of the temperature distribution inside the str ipe region. This was confirmed both experimentally and theoretically. To minimise the temperature distribution, dummy stripes mere introduce d outside the stripe region. The current in the dummy stripes did not cause lasing, but did increase the temperature of the edge stripes, wh ich improved the thermal distribution inside the stripe region. As a r esult, complete single lateral 180 degrees mode operation under contin uous wave operation was attained.