Strained quantum wells for polarization-independent electrooptic waveguide switches

A polarization-independent quantum well waveguide switch is demonstrated. By altering the composition and hence the degree of built-in strain, the bandgap of In/sub 1-x/Ga/sub x/As/InP quantum wells is engineered to produce equal field-induced refractive-index change in TE and TM polarizations. At the same time, the enhanced electrooptic effects characteristic of unstrained quantum wells are maintained, such that the voltage-length product for switching is only 3 V-mm.<
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