  The wavelength switching dynamics of two-colour semiconductor lasers with
optical injection and feedback are presented. These devices incorporate slotted
regions etched into the laser ridge waveguide for tailoring the output
spectrum. Experimental measurements are presented demonstrating that optical
injection in one or both modes of these devices can induce wavelength
bistability. Measured switching dynamics with modulated optical injection are
shown to be in excellent agreement with numerical simulations based on a simple
rate equation model. We also demonstrate experimentally that time-delayed
optical feedback can induce wavelength bistability for short external cavity
lengths. Numerical simulations indicate that this two-colour optical feedback
system can provide fast optical memory functionality based on injected optical
pulses without the need for an external holding beam.
