Electroabsorptive Fabry-Perot reflection modulators with asymmetric mirrors

A normally-on electroabsorptive surface-normal Fabry-Perot reflection modulator is reported with an on/off ratio of 22, insertion loss of 3.7 dB, and bandwidth of 3.4 nm for an operating voltage swing of 11 V. The asymmetric Fabry-Perot structure is made with asymmetric mirrors using a quarter-wavelength grating of 15 1/2-periods on the bottom and an air-semiconductor interface on the top. The active region is 1.4 mu m thick and composed of 100AA GaAs/100 A Al/sub 0.2/Ga/sub 0.8/As multiple quantum wells. The structure provides both high-efficiency and bandwidth for surface-normal modulators.<
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