© 2021 World Scientific Publishing Company.Effect of high bandgap 0.5 nm AlAs on the electronic and optical properties of the In0.70Ga0.03As/Al0.60In0.40As superlattice is investigated by using effective mass approximation under the electric field. Electronic transitions are obtained as 403 and 023 eV for E32 and E21 in the gain region. Thin AlAs increases electron confinement in the superlattice and prevents electron leakage in the gain region which mostly results in higher absorption/emission in the superlattice. AlAs has no major effects on transitions energies in the gain region but it is effectively decreasing the total absorption in the injector region and preventing the internal absorption. AlAs also makes the superlattice optically more stable by decreasing the high refractive index change in the injector region by factor 5.