CW operation of InGaN MQW laser diodes

The performance characteristic of continuous-wave (cw) InGaN multiple-quant um-well (MQW) laser diodes with optimized design parameters Is reported Roo m temperature, cw operation of InGaN MQW laser diodes was demonstrated with threshold current densities as low as 7 kA/cm(2) and emission wavelength n ear 400 nm. For 2 mu m x 300 mu m ridge waveguide nitride laser with reflec tion-coated mirrors cw threshold currents of 60 mA have been obtained. CW o peration was observed up to temperatures of 60 degrees C. The transverse an d lateral optical modes of nitride lasers, toward optimization of the layer structure and ridge waveguide parameters have been analyzed. Incorporation of a thick, superlattice n-cladding layer led to a considerable improvemen t in the transverse beam quality. Thermal modeling indicated the importance of lowering the diode voltage and efficient heat dissipation; and specific ally, the benefit of thinning the sapphire substrate for achieving room tem perature cw operation.