Embodiments described herein provide for methods of forming angled optical device structures. The methods described herein utilize etching a mandrel material with an etch chemistry that is selective to the hardmask, i.e., the mandrel material is etched at a higher rate than the hardmask. Therefore, mandrel trenches are formed in the mandrel material. Device material of the angled optical device structures to be formed is deposited on the plurality of angled mandrels. An angled etch process is performed on portions of the device material such that the angled optical device structures are formed.