An optical assembly includes a waveguide assembly and an optical coupling element. The waveguide assembly includes a core, a cladding portion, and, preferably, at least two waveguide core fiducials, the at least two waveguide core fiducials and the core being lithographically formed substantially simultaneously in a substantially coplanar layer. The core and the at least two waveguide core fiducials are formed in a predetermined relationship with the cladding portion. The optical coupling element (for example, a lens array or mechanical transfer (MT) ferrule), includes an optical element and, preferably, at least two alignment features associated with the optical element, the at least two alignment features being mated with the at least two waveguide core fiducials to accurately position the optical element with respect to the core in an X-Y plane. A method of alignment is also provided.