The study on InGaAsP/InGaAs MQW-LD with symmetric and asymmetric separate confinement heterostructure

We improved the performance of InGaAsP/InGaAs 1.55 /spl mu/m multi-quantum well laser diodes with differently highly p-doped layers in the two-step separate confinement heterostructure (SCH) by inserting additional InGaAsP layer in n-SCH, which makes asymmetric field distribution and reduces the optical loss in highly p-doped regions. To reduce the inevitable optical loss that maybe due to high-level doping, we inserted additional 100 nm InGaAsP layer in the 1st n-SCH, which shifts the field distribution from highly p-doped regions with high loss to intrinsic or n-doped region with relatively low loss, and improved the light-current characteristics.