TOKYO -- Oki Electric Industry Co., Ltd. (TSE: 6703) today announced that the company has succeeded in developing the world’s smallest silicon-based microlens, allowing for mass-production of high-performance optical components at low cost for the metro and access-network markets. This microlens improves the performance of optical components, as it can be used for surface-mount technology (SMT), a popular method for the mass-production of low-end optical components at low cost. The cost of the microlens itself is also reduced by more than ten fold, as it is produced using LSI fabrication technology."Because it enables production in volume of high-performance optical components at very low cost, I believe that this microlens and its associated technology will meet growing optical market requirements, in particular those of the metro and access network markets, where many network carriers are presenting severe competition. This will help in the deployment of broadband access," said Harushige Sugimoto, General Manager of the Corporate Research and Development Center at Oki Electric. Oki employs silicon diffractive optical elements (DOE) for the microlens, as silicon is transparent at the wavelengths of 1.3-µm and 1.55-µm used for mid- to long-distance optical communications. Combining conventional LSI mass-production technology and deep etching technology now popular in micromachine fabrication, Oki has succeeded in reducing the diameter of the microlens to 125-µm, identical to that of an optical fiber. This enables the microlens to be used in the conventional SMT process for optical components. The SMT process uses a silicon substrate featuring a V-shaped groove for the optical fiber attachment; a laser diode chip is mounted on the top surface of the substrate using alignment marks. This structure allows for fully automated assembly of optical components enabling low-cost mass-production. Until now, however, virtually no lens has been available for use in the SMT process, and only a small portion of the light from the laser diode could be coupled into the optical fiber. The microlens developed by Oki shares the same V-shaped groove as the optical fiber, enabling the microlens to be automatically aligned between the laser diode and the optical fiber. Oki Electric Industry Co. Ltd.