Experimental and theoretical studies of a novel hetero-nipi reflection modulator

A novel GaAs/Al/sub 0.35/Ga/sub 0.65/As hetero-nipi all-optical reflection modulator has been investigated, both theoretically and experimentally. The modulation is found to be dominated by the refractive index changes that occur in the quantum wells as a result of optically induced electric field changes via the quantum-confined Stark effect. Good agreement is found between the theoretical and experimental behavior, with a maximum absolute experimental modulation of 11% and a maximum contrast ratio of 4.4:1 being observed at room temperature at optical pump densities of only 1.9 mW/cm/sup 2/. A numerical model of the device is developed, which predicts large reflectivity modulations of greater than 53% with a contrast ratio of 25:1 in optimized device structures.<
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