Comparison of electroabsorption in asymmetric triangular and rectangular GaAs/AlxGa1−xAs multiple quantum wells

We present the first detailed experimental comparison of electroabsorption in equivalent rectangular and asymmetric triangular multiple quantum wells. The absorption spectra are extracted from reflectance and transmittance measurements on molecular beam epitaxy-grown samples. With absorption edges at the same photon energy, the asymmetric triangular quantum well is much wider than its rectangular well counterpart which reduces its absorption coefficient by approximately a factor of nine compared to the rectangular well, in agreement with theoretical estimates. Implications for electroabsorption modulator devices are discussed.