A Silicon-based laser sub-assembly

Silicon is used as a packaging medium to integrate a laser, lenses, and a back facet monitor into a compact sub-assembly suitable for low-cost laser packages. The sub-assembly consists of separate laser and detector/optics submounts made of silicon. Only a single axis alignment is required during assembly to align the lenses ( 3 0 0 ~ diameter sapphire spheres) with the laser active area. In a single lens configuration, the integrated sub-assembly had 25% coupling efficiency into single-mode fiber compared to 30% maximum coupling efficiency achieved on the optical bench. Coupling efficiencies of the integrated sub-assembly to 50pm multi-mode fiber greater than 70% were achieved. The effective numerical aperture of the back facet monitor in the sub-assembly was greater than 0.7.