Quantum well intermixing with high spatial selectivityusing a pulsed lasertechnique

The authors demonstrate a new quantum well intermixing technique which allows bandgap shifts of typically 100 meV to be realised with a high spatial resolution in a GaInAs/GaInAsP MQW waveguide structure. The material was irradiated with pulses from a Q-switched Nd:YAG laser, and was then subjected to rapid thermal annealing at 700°C for several minutes. The spatial resolution of the disordering process was investigated across a masked interface, and was determined to be ≤25 µm.