Ultrashort pulse controlled all-optical modulation by intersubband-coupled-interband transitions in doped quantum wells

Ultrafast all-optical modulation of interband (IB) resonant light by intersubband (ISB) resonant light in quantum wells (QW) is attractive for its application to multiplexers and demultiplexers for Tbit/s ultrafast OTDM systems. To achieve high nonlinearities in the femtosecond regime, we consider the application of ultrashort ISB light pulses maintaining the optical energy sufficiently low for device operations. We propose a novel scheme based on the simultaneous use of ISB-control and IB-signal lights both in the pulse form.