Increased optical saturation intensities in GaInAs multiple quantum wells by the use of AlGaInAs barriers

Quaternary AlGaInAs is demonstrated to be an excellent barrier material for long-wavelength quantum well modulators. In addition to lower trap density than ternary AlInAs, the low valence-band discontinuity results in saturation intensities at least a factor of 30 higher than InGaAs wells with InP barriers. Decreasing barrier thicknesses increases saturation intensities by an additional factor of 5.