Significant improvement of electroabsorption saturation intensity by use of AlGaInAs as barriers for GaInAs multiple quantum wells

It is shown that quaternary AlGaInAs is an excellent barrier material for long wavelength modulators using GaInAs quantum wells. Quaternary AlGaInAs has a lower trap density than ternary AlInAs. A low valence-band discontinuity results in saturation intensities at least a factor of 30 higher than those obtained with InP barriers. Decreasing the barrier thickness increases saturation intensities by an additional factor of five.<
>