Polymer silicon hybrid systems: A platform for practical nonlinear optics

Nonlinear optical polymers can provide a unique and powerful platform for building a number of useful optical devices. Traditionally, they have been used in all-polymer waveguiding systems, which have had a number of severe practical limitations. Silicon has recently become a popular material for integrated optical systems, but it lacks strong nonlinear properties. By combining nonlinear optical polymer claddings and silicon waveguides in a hybrid system, we show that a number of significant advantages are obtained. In particular, fabrication can be done using conventional CMOS processing, with the polymer added as part of back-end processes (after all of the high-temperature processing is completed), and the waveguide structure can also serve as an ultracompact set of electrodes. We discuss some optical devices that have recently been built into this system, which already show superior performance to anything achieved in silicon or polymer alone. We also propose using second-order nonlinear polymers with silicon for parametric amplification and oscillation and predict that such devices could exhibit extraordinary performance.