An optical bench includes a substrate having a trench therein, and a light emitting device within the trench. The optical bench further includes a light receiving device optically connected to the light emitting device. The optical bench further includes at least one active circuit electrically connected to the light emitting device. The optical bench further includes a waveguide in the trench, wherein the waveguide is optically between the light emitting device and the light receiving device. The optical bench further includes an optically transparent material between the light emitting device and the waveguide.