PRISM-LIKE FOLDED CAVITY SURFACE-EMITTING LASER-DIODE - ELECTROMAGNETIC-THRESHOLD ANALYSIS

A novel structure for a surface-emitting laser diode with prism-like f olded cavity is proposed. Walls of this cavity form a 90 degrees corne r with total internal reflection. As a result, only one output mirror (at the substrate side) is needed, allowing the cavity to be in proxim ity with the top contact and thus reducing device resistances. A metho d of technical realisation of the device is proposed briefly. Simple e lectromagnetic-threshold analysis predicts location of the cavity mode s in the gain spectral range of the GaAs active medium, indicating con ditions for single-mode operation. It is found that an optical-field d istribution can be approximated as a (folded) wave with a plane wavefr ont inside the cavity of even and odd modes.