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T. H. Wood, C. A. Burrus, D. A. B. Miller,
D. S. Chemla, T. C. Damen, A. C. Gossard and W. Wiegmann, "High-Speed Optical
Modulation with GaAs/GaAlAs Quantum Wells in a p-i-n Diode Structure," Appl. Phys.
Lett. 44, 16-18 (1984). A new type of high-speed optical modulator is
proposed and demonstrated. An electric field is applied perpendicular to GaAs/GaAlAs
multiple quantum well layers using a 'p-i-n' diode doping structure of 4- mu m total
thickness. The optical absorption edge, which is particularly abrupt because of exciton
resonances, shifts to longer wavelengths with increasing field giving almost a factor of 2
reduction in transmission at 857 nm with an 8-V reverse bias. The shifts are ascribed to
changes in carrier confinement energies in the wells. The observed switching time of 2.8
ns is attributed to RC time constant and instrumental limitations only, and fundamental
limits may be much faster
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