Picosecond All-Optical Switching of a Quantum Well Etalon Using Spin-Polarization Relaxation and Electron Tunneling

Recently strong emphasis is put on searching for a large and fast nonlinear optical material to realize all-optical switching. In fact, ultrafast optical switching is expected to be very important in future ultra-high bit rate optical network in such a role as an interface between electronic circuits and optical systems. The multiple quantum well (MQW) structure has attracted much attention due to its remarkably large optical nonlinearity in excitonic absorption bleaching. However, absorption recovery in MQWs takes tens of nanoseconds due to the restriction by the recombination lifetime.