Low-saturation-energy-driven ultrafast all-optical switching operation in (CdS/ZnSe)/BeTe intersubband transition

The authors report their latest results on II-VI intersubband all-optical switches in which the 10 dB absorption saturation energy is lowered to ~2.0-2.2 pJ for 1.55-1.58 mum by decreasing the thickness of the active layer and increasing the refractive index difference between the core layer and the cladding layers in waveguides. Such low saturation energies greatly improve the switching performance.