Optical transitions between light hole subbands in InGaAs/InP strained layer multiquantum wells

The observation of light hole intersubband absorption in both p‐doped and photoexcited undoped strained InxGa1−xAs/InP (x≂0.35) quantum‐well structures is reported. 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.