All-optical switching and memorizing devices using resonant photon tunneling effect in multi-layered GaAs/AlGaAs structures

We propose a new structure for all-optical switch (AOS) and all-optical memory (AOM) devices that use the resonant photon tunneling effect in multi-layered GaAs/AlGaAs structures. Numerical calculations revealed a sharp peak in tunneling probability at a resonant incidence angle in double-barrier AOS structures. The resonance angle can be controlled by changing the refractive index of an active layer. During simulation, we demonstrated that the AOS with the new structure acts as an all-optical NOT gate. We also found that optical bi-stability occurs in the dependence of reflectivity on control light intensity. This bi-stability is caused by the penetration of intense input light to the active layer based on the resonant photon tunneling effect, and it is clear that an AOM can be achieved through this bi-stability effect. These results indicate that the resonant photon tunneling effect in multi-layered semiconductor structures can effectively be used to attain efficient all-optical devices.