Vertical n-i-n multiple-quantum-well electrooptical modulators for high-speed applications

The authors report on a vertical n-i-n AlGaAs multiple-quantum-well electrooptical modulator with a reflectivity change of 40% and a contrast ratio of 6 dB (0 to 10 V) with a corresponding insertion loss of 2.5 dB. The current of the device is kept low by using undoped barrier layers cladding the intrinsic quantum-well region. The efficiency of this device is comparable to that of a device using a pin structure. Modulation in the gigahertz region has been observed by using a coplanar traveling-wave structure yielding a slowing factor of about 93 at a frequency of 1 GHz.<
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