Epoxyless Fiber-to-Submount Bonding for Active Fiber Optoelectronic and Fiber Backplane Applications

A fiber-coupled optical transmitter or receiver is both a mechanical and an optical system. Packaging of optical components like fiber-coupled lasers requires good coupling into the fiber, and rigid inflexible mounting of all components, so the coupling remains stable over the multiyear lifetime expected of optoelectronic components. In this paper, we report a new technique for bonding fiber directly to a Si or glass submount for autoaligned direct fiber attachment, based on field-assisted anodic or cathodic bonding. Under the influence of an electric field at high temperature, oxides are formed between the glass and the metal: this method is used to bond both metallized fibers to a glass V-groove (cathodic bonding), and glass fibers to a metallized Si submount (anodic bonding), without epoxy. Typical shear strengths are >300 g, comparable to solder-mounted components. The V-grooves precisely align the fiber to the component in two of the three dimensions. The thermal stability of this technique is demonstrated through showing <0.1 dB variation in coupling between two bonded fibers in aV-groove over a temperature range of 25degC-85degC. This method of fiber attachment is a robust and economical way to attach fibers for passive alignment and direct butt-coupling between the fiber and the semiconductor laser, receiver, or other optoelectronic component