Inter-light-hole subband absorption in tensile strained InGaAs/InP quantum wells

Abstract We report the observation of light hole intersubband absorption in both p-doped and photoexcited undoped tensile strained In x Ga 1− x As/InP ( x ≃0.35) quantum-well structures. The absorption is polarized along the growth direction and is in agreement with calculations which show that the strain causes the light hole level to be first occupied upon p-doping or photoexcitation. Both impurity bound and free holes transitions are identified.