26.5 GHz bandwidth InGaAsP lasers with tight optical confinement

By reducing the active-layer width of constricted-mesa lasers to 1 ?m, we have increased 20°C CW bandwidth to 16 GHz and the -60°C bandwidth to 26.5 GHz. The pulsed 20°C bandwidth is 22 GHz, indicating that the present bandwidth limitation is predominantly thermal. Optical transmission systems with bandwidths spanning the S, G, J, X, P and K microwave waveguide bands simultaneously are now possible.