12W CW operation of 640nm-band laser diode array

A high-power and short-wavelength GaInP/AlGaInP quantum-well laser diode array was designed and fabricated. Because a conduction band offset of this material system is small, a carrier leakage from an active layer is an important limiting factor of the maximum light output. In this work, long cavity length of 1.5 mm, high front facet reflectivity of 18% and AlInP cladding layers were adopted to reduce the leakage. An evaluation test of the fabricated array was performed under CW operation. At 15 degrees C, high light output of 12W was obtained with injection current of 16A. The lasing wavelength was 643.3 nm. Moreover, high wall-plug efficiency of 34% was achieved. These excellent characteristics are considered to be due to the effective suppression of the carrier leakage.