Abstract: An optical subassembly comprises a micro-optical bench and a corresponding molded device submount having an optical detector, LED, or laser diode mounted thereon. The optical bench is a semiconductor wafer having one or more grooves etched therein. A submount groove is designed to receive a cooperating ridge on a bottom surface of the molded device submount so as to limit the movement of the submount on the optical bench. An optical fiber is secured in an alignment groove and secured to the optical bench. To complete the subassembly, it is only necessary to set the axial distance between the optical detector, LED, or laser diode and a distal end of the optical fiber. A fiber stop incorporated into the micro-optical bench automatically adjusts the axial positioning of the distal end of the fiber to the optical detector, LED, or laser diode. In addition, a hermetically sealed package is provided with a faceplate that is secured to the package.