Microjet printing of high precision microlens array for packaging of fiber-optic components

A significant advance in technical capability has recently been achieved in the fabrication of refractive microlens arrays by microjet printing. This advance enables control of lens diameter and center-to-center distances to accuracies on the order of +/-1 mum, and of focal length variations within an array to less than the +/-1%. Such accuracies are especially important for microlens arrays used for MOEMS device interconnects to optical fibers because of the relatively long free space optical path lengths required for such applications. The new process also enables the printing of microlenses of a given diameter with aspect ratios and focal lengths varying over a wide range (e.g., f/1-f/5). The profile of plano-convex microlenses printed by this method have exhibited less than a quarter wavelength of deviation from spherical surface. The thermal durability of the optical epoxies used for microlens printing enables both cycling temperature up to 200degreesC and continuous exposure to thousands of hours at 85degreesC, without affecting microlens performance. The microjet printing of lensed fibers provides another solution for fiber beam shaping and collimation with low production cost.