Nonlinear optic polymer electro-optic modulators for space applications

Optoelectronic devices based on nonlinear optic (NLO) polymers, with electro-optic (EO) coefficients in excess of 100 pm/V at 1.06 μm and dielectric constants of <3, have demonstrated 100+ GHz data rates with less than 4 volt operating voltages. This has gained interest from the space based applications community, since in addition to being tolerant to a space environment, electro-optic devices for space applications will also need to operate at high data rates and at low operational powers. We have investigated various NLO polymers for core materials as well as passive polymers with various conductivities, both ionic and electronic, suitable for use as optical cladding layers in NLO polymer based opto-electronic devices. Our goal was to find materials that would be tolerant to irradiation as well as maximizing the nonlinearity of the NLO core material, thus minimizing the total applied poling voltage, and minimize the optical absorption loss. Using a cladding material that is more conductive than the NLO core material, the majority of the applied poling voltage is dropped across the core, thus maximizing the EO coefficient with minimum applied voltage or power. We found, however, that it is necessary to balance the optical and electromagnetic properties of the materials with their processability and compatibility.