SUPPRESSION OF SIDE LOBES IN THE FAR FIELD OF ALGAAS DH STRIPE LASERS BY A TE FACET COATING

Side lobes observed in the far-field distribution parallel to the junction plane of DH AlGaAs stripe-geometry lasers can be suppressed by a self-aligned facet masking process. A hole, burnt into a Te coating by the laser emission, allows only the main lobe emission to pass. The result supports the attribution of side lobes to refraction tails in the near field typical of a negative refractive index step wave guide as discussed in a previous paper [see R. W. Engelmann, D. Kerps, and F. Nunes, IEEE Quantum Electron. (to be published)].