M. Zimmermann et al., CARRIER TRANSPORT IN ASYMMETRICALLY CONFINED 1.55 MU-M MULTIPLE-QUANTUM-WELL LASER STRUCTURES, Applied physics letters, 69(16), 1996, pp. 2324-2326
Asymmetrically confined multiple quantum well laser structures have re
cently been very successful in reaching high modulation bandwidths up
to 26 GHz, reported in the IncaAs/InGaAlAs material system. We have me
asured the effective carrier transport time in structures of this kind
by performing parasitic-free optical modulation experiments. The resu
lt is one specific transport time for each confinement layer width. We
show that down to layer widths of about 100 nm this effective time fo
r both types of carriers is given by a pure diffusion process for InGa
As/InGaAlAs. Finally, a diffusion constant for the barrier/confinement
carriers results in InGaAlAs material which is in very good agreement
with reported mobilities. (C) 1996 American Institute of Physics.