Demonstration of polarisation rotation gate in GaAs/AlGaAs multiquantum well waveguides

Optical switching of femtosecond pulses is achieved at 1.5 μm using a refractive nonlinearity in a GaAs/AlGaAs MQW waveguide birefringent gate. The switching mechanism is demonstrated with a maximum throughput of 54% of the available transmitted power corresponding to an effective phase shift between polarisations of 90 o . Normalised transmission is increased by a factor of 44 by increasing the peak coupled pump power from 1 to 330 W