Electroabsorption

Marı́a Aguilar, M. Carrascosa, Fernando Agulló-López +3 more

Electroabsorption has been investigated in semi-insulating asymmetric GaAs/AlGaAs double quantum wells presenting high linear Stark responses, adequate for photorefractive applications. We have used the envelope function approximation to calculate the linear Stark shifts of the energy levels and select a suitable structure for the experimental study. The experimental data indicate that the response to the applied field critically depends on a complicated interplay of effects that compete or cooperate to suppress or enhance the electroabsorption. For positive field polarity, the competing contributions of the overlapping e1–hh1 and e1–hh2 transitions partially cancel the electroabsorption despite large linear Stark shifts. On the other hand, small negative fields induce large electroabsorption because the Stark shifts of the two transitions have opposite signs.

David A. B. Miller

Electric fields in semiconductors can produce large changes in optical absorption, especially in the presence of excitonic absorption resonances. Strong room temperature exciton lines and novel electroabsorption processes in quantum-well structures have stimulated increased interest in this field.

Maria Maragkou

O.-K. Kwon, Kyung-Sook Hyun, K. Kim +3 more

Summary form only given. We have successfully demonstrated an improved nonbiased optical bistability in an GaAs-AlGaAs QW electroabsorption modulator by utilizing nonresonant p-i-n-i-p structure, which has large E while maintaining sufficient light absorption with no external bias.