Semiconductor Diode Laser Mode-Locking by a Waveguide Array

We demonstrate theoretically that robust mode-locking can be achieved in an edge-emitting semiconductor diode laser with a waveguide array architecture. The waveguide array provides an ideal saturable absorption mechanism for initial start-up from noise, as well as pulse shaping and stabilization. One element in the waveguide array is forward-biased to generate gain, while nonlinear coupling to the other elements results in an effective saturable absorber. This new approach can be integrated directly with standard edge-emitting designs.