Microjet printing of micro-optical interconnects and sensors

The microjet printing method is being used to fabricate microlens arrays for use in massively parallel, VCSEL-based datacom switches and to deposit lenslets of various configurations onto the tips of single-mode telecom fibers. Applications in the latter case include collimation of the output beams for free space optical interconnection and increasing the fiber numerical aperture for collection of light from edge-emitting diode lasers. Additional applications of this technology include printing of arrays of active sensor elements onto the tips of imaging fiber bundles and fabrication of microlenses with axial index of refraction gradients to reduce focal spot size, utilizing multiple print heads with differing fluids. This low-cost, data-driven process, based on "drop-on-demand" inkjet technology, involves the dispensing and placing of precisely sized microdroplets of optical material onto optical substrates. The micro-optical elements are printed with 100% solid, UV-curing optical epoxies, utilizing printing devices that can dispense picoliter-volume droplets at temperatures up to 300 degrees C.