September 26, 2005 Lisle, IL -- Molex, in a joint effort with KiloLambda Technologies, has developed an improved method of coupling light between optical fibers and silicon waveguides. According to the companies, the new method enables engineers to simplify coupling mechanics and improve coupling efficiency for optical component applications where efficient coupling of light is required between optical fiber and planar waveguide-based optical devices. Applications, according to the companies, include arrayed waveguides (AWG), splitters, couplers, waveguide filters, silicon lasers, and modulators.
According to the companies, optical researchers have long faced difficulties in coupling light into and out of non-silica based waveguide devices using optical fiber. The companies say this was mainly due to the large mismatch between the common telecommunications grade optical fiber core dimension and that of high-index-contrast waveguides manufactured from Silicon, Indium Phosphide, Gallium Arsenide, or polymers. The companies say this challenge prompted them to jointly develop a method to effectively couple light in this situation. The company's project engineers accomplished this by incorporating a waveguide section that is tapered vertically, as well as laterally (2-D taper), between the fiber and the waveguide. The engineers then simulated, designed and fabricated a 2-D tapered section in a silicon waveguide, which improved the coupling efficiency between an optical fiber and the silicon waveguide by a factor of ~ 4.
The two companies say they are currently seeking parties interested in licensing and further development of this technology. The project has been partially sponsored by the Bi-national Industrial Research and Development (BIRD) foundation established between the governments of the U.S. and Israel. Additionally, a technical paper documenting the newly developed coupling method was published in the September 2005 issue of IEEE Photonics Technology Letters (PTL).