Unstable waveguiding in VCSELs

It has been known for a long time that unstable waveguiding can occur in planar, gain guided stripe lasers. The possible existence of instabilities can be demonstrated by a very simple waveguide calculation. In this letter the demonstration of possible instabilities is extended to structures with cylindrical geometry. On the basis of these results it is concluded that unstable waveguiding may exist in cylindrical vertical cavity surface emitting lasers.<
>