Nonlinear all-optical GaN∕AlGaN multi-quantum-well devices for 100Gb∕s applications at λ=1.55μm

Using quantum-mechanical analysis, a strain-balanced stack of coupled GaN∕AlGaN quantum wells has been engineered for bandwidth-optimized all-optical switching at low switching powers. Intersubband transitions between three conduction subbands provide the basis for the large, fast, nonlinear optical response. Optimized performance for a given symbol rate is obtained by engineering the response time and nonlinear phase shift.