Optical and structural properties of metamorphic InGaAs/AlAsSb quantum wells grown on GaAs substrates

Metamorphic InGaAs/AlAsSb multiple quantum wells (M-MQWs) were grown on GaAs. The M-MQWs were evaluated by X-ray diffraction, photoluminescence and polarity dependent optical absorption measurements. These measurements revealed that M-MQWs had good structural and optical qualities. M-MQWs with high sheet carrier densities (ges 10
¹²
/cm
²
) clearly showed absorptions in TM polarized light corresponding to intersubband transitions (ISBTs). Therefore, the M-MQWs can be applied to ultra fast optical modulators using the ISBTs