Optical characterization of InGaAs-InAlAs strained-layer superlattices grown by molecular beam epitaxy

InGaAs-InAlAs strained-layer superlattices, with both controlled strain magnitude and direction in the narrower gap layers, were grown by molecular beam epitaxy. Exciton related peaks and steplike structures in transmission spectra were clearly observed even at room temperature. The close agreement of these observed peak positions with theoretical calculations indicates that heavy-hole and light-hole level reversal was attained in the tensile-strained narrower gap layers.