The design, fabrication and characterisation of a short wavelength (ap
proximately 860 nm) quantum well AlGaAs/GaAs monolithic colliding puls
e modelocked (CPM) laser are described. Devices with modelocked operat
ion repetition rates in the range 73-129 GHz and pulse widths less tha
n 2 ps are described. The importance of the polarisation dependence of
the saturable absorber and the gain section in the operation of a qua
ntum well monolithic CPM is discussed.