REFRACTIVE-INDEX AND ABSORPTION OF GAAS QUANTUM-WELLS ACROSS EXCITONIC RESONANCES

We present simultaneous measurement of the refractive index and absorp tion coefficient in a AlGaAs/GaAs multiple quantum well structure near the band gap by Fourier transform spectral interferometry. Both quant ities were measured across heavy- and light-hole excitons for temperat ures ranging from liquid helium to room temperature. The experimental results are analyzed using an analytical expression for the complex di electric function of Wannier excitons in fractional dimension. (C) 199 8 American Institute of Physics. [S0003-6951(98)03042-3].