Stark effect in strongly coupled quantum wells

The energies and oscillator strengths of the excitonic transitions in a pair of strongly coupled quantum wells in the GaAs/Alₓ{Ga}_{1{{-}}x}$As system have been experimentally investigated as a function of electric field and compared with an effective-mass calculation which neglects band mixing. Good agreement with experiment can be obtained by taking into account nonparabolicity in the light-hole bands. Although not readily evident in the field dependence of the excitonic transition energies, band mixing has a measurable effect on exciton linewidths. The optoelectronic device implications of the Stark effect observed in this system are briefly considered.