Hybrid Integration of the Wavelength-Tunable Laser With a Silicon Photonic Integrated Circuit

A technology for hybridly integrating a discrete edge-emitting laser with a submicrometer silicon-on-insulator waveguide is presented. This technology is based on a ceramic microoptical bench which is compatible with high-speed electrical direct modulation. The use of passive- and self-alignment techniques is demonstrated to be suitable for assembling the microoptical bench with the laser die and optical components. The placement tolerance of less than 1 dB loss over a 4 
$\mu$
m range during the final integration with the waveguide is suited to a passive alignment process as well, thus permitting wafer-scale assembly and mass manufacture. The integration of both a Fabry–Pérot laser and a two-section electrically tunable multiwavelength laser was performed. An excess insertion loss of only 3.36 dB was measured, which combined with state-of-the-art grating couplers promises a coupling efficiency from laser to waveguide of better than 40%.