High Power Operation of AlGaInP Red Laser Diode for Display Applications

Substantial limitation of output power in AlGaInP based red broad area (BA) laser diode (LD) originates from an electron thermal overflow from an active layer to a p-cladding layer and fatal failure due to catastrophic optical mirror degradation during the LD operation. New red BA-LD was designed and fabricated. The LD chip had triple emitters in one chip with each stripe width of 60 um, and was assembled on phi 9.0 mm -TO package. The LD emitted exceeding 5.5 W at heat sink temperature of 25 degrees C and 3.8W at 45 degrees C under pulsed operation with frequency of 120Hz and duty of 30%, although the current product, which has a 40 um single emitter chip assembled on phi 5.6mm -TO, does 2.0 W at 25 degrees C. The lasing wavelength at 25 degrees C and 2.5W output was 638.6 nm. The preliminary aging test under the condition with the operation current of 3.56A, CW, auto-current-control mode (ACC), and the heat sink temperature of 20 degrees C (almost equal to the output of 3.5 W) indicated that the MTTF due to COMD was longer than 6,600 hours under CW, 22,000 hours under the pulse with duty of 30%.