Methods are disclosed of fabricating an optical assembly. An active
optical element is disposed near or on a first surface of a slab of
optical material. A passive optical element is formed on a second surface
of the slab, with the second surface being substantially parallel to the
first surface. An optical axis of the passive optical element is aligned
with an optical path between the passive optical element and an active
region of the active optical element using a lithographic alignment
process.