Novel Modulator Structure Permitting Synchronous Band Filling of Multiple Quantum Wells and Extremely Large Phase Shifts (Suggested Area: Quantum Electronics and Compound Semiconductor Devices)
03 December 1989
A new bandgap engineered structure that makes it possible to realize synchronous charge control in multiple quantum wells is demonstrated. The measured electroabsorptive and electrorefractive properties show that for a given absorption loss the maximum achievable phase shift in a waveguide is conservatively one order of magnitude greater than what is possible in a modulator based on quantum confined Stark effect (QCSE) with similar quantum wells. Furthermore, the electric field dependence of refractive index change in the new structure is linear rather than quadratic.