FABRICATION AND COUPLING-TO-FIBER CHARACTERISTICS OF LASER-DIODES INTEGRATED WITH A SPOT-SIZE CONVERTER HAVING A LATERAL TAPER

Laser diodes monolithically integrated with spot-size converters opera ting at 1.3 mu m, and having an almost circular narrow emitted beam, h ave been successfully fabricated using 2 inch (50.8mm) full wafer fabr ication technology. The spot-size converters consist of a lateral tape r, thin-film guiding layer and ridge structure. The epitaxial structur e is designed to have wide fabrication tolerance with no deterioration of device characteristics. The investigation of the coupling-loss dep endence on the dimension parameters in the spot-size converters confir ms that this device has a wide fabrication tolerance for these paramet ers. Furthermore, butt-coupling loss to fibre as low as -1.3dB is atta ined with alignment tolerance wide enough for passive alignment. The o verall device is as short as 450 mu m, enabling high availability from one wafer.