US Patent 9229169 Lens array optical coupling to photonic chip

A photonic integrated circuit apparatus is disclosed. The apparatus includes a photonic chip and a lens array coupling element. The photonic chip includes a waveguide at a side edge surface of the photonic chip. The lens array coupling element is mounted on a top surface of the photonic chip and on the side edge surface. The coupling element includes a lens array that is configured to modify spot sizes of light traversing to or from the waveguide. The coupling element further includes an overhang on a side of the coupling element that opposes the lens array and that abuts the top surface of the photonic chip. The overhang includes a vertical stop surface that has a depth configured to horizontally align an edge of the waveguide with a focal length of the lens array and that vertically aligns focal points of the lens array with the edge of the waveguide.