Multicolor Lithography for High Efficiency, Low Insertion Loss NLO

Recent advances in processing concepts for waveguide fabrication in NLO polymers offer the potential for precise local control of refractive index gradients within polymer thin films. These index control approaches can be used to create large, buried, single-mode waveguides for low loss pigtailing to optical fibers. The same techniques can also be used to create buried, 3-dimensional waveguide tapers within the films which smoothly transition to smaller waveguides within the electroded regions of optical devices for greater electrical responsivity. This allows the use of small waveguides which can experience higher electric fields to greatly reduce drive voltages. Advanced processing is also proposed for these smaller guides so that they tightly confine light (small, single-mode waveguides having large refractive index gradients) to eliminate the major source of optical loss in narrow electrode gap designs, the absorption of evanescent light by nearby metallic surfaces. Feasibility demonstrations of these new processes in conjunction with other techniques such as ion etching are proposed for developing innovative approaches for reducing pigtailing cost, reducing optical losses, and reducing drive voltages in integrated optical devices. The processing of such NLO polymers holds great promise for ultrafast (50 GHz), high performance components and interconnects. Besides military applications such as active interconnects, radar detection, and RF communication, this development offers great potential for cable TV and telephone industry applications.