A planar wafer-level packaging method is provided for a laser and a monitor photo
detector. The laser and photo detector are affixed to a planar substrate. The planar
substrate provides electrical connections to the components. A lens cap with a
microlens is formed and affixed to the substrate with a seal. The lens cap forms
a hermetically sealed cavity enclosing the laser and photo detector. The inside
surface of the lens cap has a reflective coating with a central opening over the
emitting aperture of the laser. The central opening has an anti-reflective coating.
Light from the laser is directed and shaped by the lens cap to couple into an external
light guide. Residual light from the edge of the laser reflects off the inside
surface of the lens cap and is incident upon the photo detector. In an alternate
method, the laser may be packaged using flip-chip assembly.