Single transverse-mode filtering utilizing ion implantation: Application to 1.48-mu m unstable-cavity lasers

We demonstrate the relevance of ion implantation of the multiple quantum-we ll active layer in unstable-cavity lasers as a means of efficiently filteri ng the parasitic higher order waves by introducing additional propagation l oss within the cavity, Several H+ implantation schemes are proposed and a c omparison is successfully made of experiment to a beam propagation method ( BPM) model on the basis of modal behavior. This work finally resulted in im proved single transverse-mode behavior of those lasers: more than 1.3 W CW of diffraction-limited power at 1.48 mum was then obtained utilizing a two- step implantation process.