Polymer Integrated Optic Zero-Gap Directional Coupler

Abstract

ABSTRACTIntegrated optic zero-gap directional couplers (ZGDC‘s) offer orders of magnitude shorter device lengths than conventional directional couplers. Researchers are currently striving to simultaneously optimize several properties of nonlinear optical (NLO) polymers that are viewed essential for the fabrication of commercially viable polymer electro-optic devices, including high electro-optic activity, low propagation loss and high temperature poling retention. Fabrication of zero-gap directional couplers using NLO polymers show the potential to realize devices with interaction lengths as short as 100 μm, operating at TFL level switching voltages. Hence, NLO polymer ZGDC‘s will possess the ability to tolerate large propagation losses. This can allow the low propagation loss constraint for NLO materials to be relaxed significantly. Polymers with high electro-optic activity that might be rejected because of high propagation loss, could potentially be utilized for ZGDC switches. In addition, by using these devices as stand alone switches for the present (i.e., not integrating them with electronic circuits) the de-poling temperature constraint can also be significantly relaxed since neither solder baths nor high density interconnect (HDI) processes will be needed. These relaxed constraints should improve the chances for introduction of viable NLO polymer devices that can compete in the market place today, without being forced to wait for a material in which all properties have been optimized.