Optical characterization of molecular beam epitaxial GaAs/AlxGa1−xAs multi‐quantum‐well structures using a very low power, narrow band, tunable pulsed dye laser

High‐resolution pulsed laser‐induced photoluminescence (PL) and PL excitation spectroscopy have been carried out in MBE grown GaAs/AlxGa1−xAs multi‐quantum‐well structures at 5 K. At very low laser power levels, fine structures are observed both in the heavy‐hole and the light‐hole excitonic regions. By combining a selective detection method with PL excitation spectroscopy, energy states buried under a broad spectrum can be separated.