First Results on InGaAsP Separate Confinement Heterostructure Diode Lasers

The first attempts of fabrication of InGaAsP/GaAs SCH-QW laser structures allowed to obtain laser diodes with threshold current densities as low as 47OA/sq cm and differential efficiencies as high as 0.7W/A. Long-cavity (L approx. 1mm) laser diodes have low series resistances of 0.1-0.4ohms. These diodes are suitable for testing of the properties of the Al-free material in continuous wave regime. At the same time, it is evident that further optimization of structure parameters is necessary to reach the ultimate performance expected for InGaAsP SCH QW lasers.