Low-cost fiber collimation for MOEMS switches by ink-jet printing

Micro-optoelectronic mechanical systems (MOEMS) typically rely on free-space optical interconnects for fiber array in/out connections. The fiber output collimating and input focusing functions may be performed by using either individual gradient-index-of- refraction (GRIN) microlens rods or, more typically, arrays of microlenses formed on a glass substrate, to which the fibers are butte-coupled. We present methods for fabricating, with micron precision, various configurations of micro-optics for fiber collimation using low-cost, ink-jet printing technology. These configurations range from micro-deposition of droplets of optical epoxy into the tips of fibers, positioned in either individual collets or fiber ribbon connector ferrules, to the printing of arrays of collimating/focusing microlenses onto glass substrates. In the latter case the flexibility of the data-driven printing process enables unique capabilities, such as the variation of microlens geometries within an array, in order, for example, to compensate for the varying distances between the input fibers and the individual micro-mirrors within an array of a MOEMS device. The processes and optical modeling approaches used for fabricating such fiber collimation structures utilizing ink-jet printing technology Will be discussed in detail, along with process control issues and optical performance data.