Excitonic nonlinear shifts in photonic crystal nanocavities with buried multiple quantum wells

We investigate strong excitonic absorption and large nonlinear wavelength shifts in buried multiple-quantum-well photonic crystal L3 nanocavities that well confine the carriers. The confined carriers can survive as long as the radiative lifetime because carrier diffusion is negligible and surface recombination is well suppressed. In addition, strong optical confinement and small mode volume provided by photonic crystals can enhance excitonic nonlinearity. Therefore, our structure shows a strong excitonic effect that induces large refractive index changes by exciton bleaching and exhibits a large cavity-frequency shift. Our results will contribute to the development of ultralow energy all-optical switching devices in the future.

Automated summary

Our research found strong excitonic absorption and large nonlinear wavelength shifts in buried multiple-quantum-well photonic crystal L3 nanocavities, where carriers are effectively confined. Negligible carrier diffusion and well-suppressed surface recombination allow confined carriers to survive for as long as the radiative lifetime. The strong optical confinement and small mode volume provided by photonic crystals enhance excitonic nonlinearity, leading to a significant excitonic effect that induces large refractive index changes and cavity-frequency shifts. Our findings will aid in the development of ultralow energy all-optical switching devices in the future.