The dc linear electro-optic effect and the x-ray crystal structure of the organic molecular solid 2-methyl-4-nitroaniline (MNA) have been studied. Of two crystal orientations measured, one polar orientation was found to have an exceptionally large figure of merit for electro-optic phase retardation, comparable to that of LiNbO3. Comparison with second harmonic generation results demonstrates that the linear electro-optic effect in MNA is primarily electronic in nature. The origin of the large macroscopic second order nonlinear optical susceptibility is traced to a single large component of the corresponding microscopic molecular susceptibility.

Using polyimide as host in a guest-host thin film we demonstrate the first poled-polymer electro-optic response stable at temperatures up to 150 °C (samples poled and cured at 250 °C). A coplanar-electrode poling geometry is used so that the molecular alignment of the guest dye between the electrodes is coincident with the free volume of the host. We hypothesize that ‘‘high’’ temperature poling during the imidization process, when the polyimide forms rings and densifies, accounts for the excellent poled response stability.

An electro-optic (EO) polymer-based integrated optic Mach-Zehnder modulator with a measured frequency response up to 20 GHz is reported. The device was J'abricated with an EO polymer supplied by Akzo Research, bv, and utilized 50 R microstrip drive electrodes. A half-wave voltage of V, = 9 V and a modulation depth of 90% were measured at 2 kHz. Modulation was observed out to 8.0 GHz using direct detection and out to 20 GHz using a frequency mixing technique, limited by the drive and receiver electronics.

We report development of the first all-polyimide system (cladding/core/cladding) suitable for fabrication of electro-optic waveguide devices on silicon substrates. The cladding layers are spun from a low optical loss, commercially available polyimide that is suitable for multilayer stacks. The electro-optic material consists of this same polyimide as host to a commercially available guest chromophore and is based upon our prior work on thermoplastic polyimides [J. F. Valley, J. W. Wu, S. Ermer, M. Stiller, E. S. Binkley, J. T. Kenney, G. F. Lipscomb, and R. Lytel, Appl. Phys. Lett. 60, 160 (1992)]. We present the materials and process development methodology with the results for this polymer system and demonstrate it by fabrication of an all-polyimide Mach–Zehnder modulator operating at 830 nm.

We demonstrate the first polyimide guest/host system which exhibits stable electro-optic response after parallel-plate poling. Such systems are based on a class of polyimides which, once cured, possess a clear glass transition in their dielectric relaxation spectra, characteristic of thermoplasticity. After doping with compatible nonlinear optical molecules the polyimide host system can first be thermally imidized (cured) and then poled with an electric field. High glass transition temperatures are achieved leading to excellent thermal stability of the poled electro-optic response.