An apparatus for passive alignment of optical devices comprises a substrate including a trench in a top surface thereof, where the trench has a first end positioned at an edge of the substrate and a second end positioned at an interior region of the substrate, and a lens disposed on the top surface of the substrate adjacent to the second end of the trench. The apparatus further includes a top holder having a longitudinal indentation in a bottom surface thereof for mounting an optical fiber. The longitudinal indentation is sized to fit a top portion of the optical fiber such that a bottom portion of the optical fiber extends below the bottom surface of the top holder when the optical fiber is mounted therein. One or both of the substrate and the top holder include one or more spacer features configured for three-dimensional (3D) alignment of the lens with the optical fiber when the top holder is brought into contact with the substrate.