1. ROBINSONROBINSON Use of forces to precisely position chromophores: Noncentrosymmetric ordering required. Dipole-dipole interactions oppose this ordering.  Poling and Steric Forces must be used to minimize undesired effects of dipole-dipole interactions. Uniform chromophore array (and high concentration) necessary: Maximizes electro-optic activity. Avoids optical loss from scattering due to density variations. Achieving nanostructured electro-optic materials: 1. Electric field poling of dendritic materials. 2. Sequential (layer-by-layer) synthesis from an appropriate substrate (which also serves as a cladding material). 3.Ferro-electric structures. Why Nanostructured Electro-Optic Materials?

2. ROBINSONROBINSON Quantum Mechanics H  = E  Levels of Theory: 1 st Principles Time Distance femtosec picosec nanosec microsec seconds minutes hours years 1 Å1 nm10 nmmicronmmmeters Mesoscale Dynamics Segment Averages Group Additivities Solubilities Molecular Dynamics F=MA Force Field Charges Finite Element Analysis Process Simulation Equilibrium Properties Transport Properties E & M Response and Properties Engineering Design

3. ROBINSONROBINSON Theoretically inspired rational improvement of organic electro-optic materials Theories (quantum and statistical mechanics) have guided the systematic improvement of the hyperpolarizability (  ) of organic chromophores and the electro-optic activity of macroscopic materials.

4. ROBINSONROBINSON Systematic Improvement in Molecular Electro- Optic Activity: Variation of mb

5. ROBINSONROBINSON Driven by Quantum Mechanical Calculations of Molecules That Can Be Synthesized & Processed Hyperpolarizability ( b )

6. ROBINSONROBINSON r eff   in absence of intermolecular interactions Figure of Merit

7. ROBINSONROBINSON. New Strategy: Gradient-Bridge, Mixed-Ligand-Acceptor Chromophores Quantum mechanical calculations permit the optimization of the  -electron structure that defines molecular hyperpolarizability. Microwave synthesis techniques permit dramatic enhancement in reaction yields and synthesis of new materials. New Advances in Chromophore Development

8. ROBINSONROBINSON. Microwave synthesis has permitted dramatic enhancement in reaction yields, reducing time devoted to purification. It has also permitted many materials to be synthesized for the first time and has permitted greater flexibility in reaction conditions. Microwave synthesis techniques obviously permit more uniform heating of reaction mixtures. The absence of thermal gradients and “hot spots” helps minimize decomposition and side reactions. Microwave synthesis permits the use of a wider range of solvents. We have found this approach to be particularly effective for condensation, addition, and de-protection reactions. Why Microwave Synthesis?

9. ROBINSONROBINSON Comparison of Microwave and Reflux Synthesis of CF 3 -TCF acceptor

10. ROBINSONROBINSON. Examples of Microwave Synthesis

11. ROBINSONROBINSON. Coupling Reactions

12. ROBINSONROBINSON 0.85 dB/cm at 1.55 mm 0.68 dB/cm at 1.3 mm Perfluorodendron-substituted Chromophore Contributes Little to Optical Loss in Guest-Host APC Polymer Reducing Optical Loss

13. ROBINSONROBINSON. Photochemical stability can be improved by chromophore design. Lumera has demonstrated this. Photochemical stability can be improved by the use of scavengers Optimizing Photostability

14. ROBINSONROBINSON Eye diagram 1 Gb/s, V peak = 1 V Device has ~2GHz BW Au Electrode SU-8 Gold ground GND = 2 GHz/V Integrated WDM Transmitter Receiver

15. ROBINSONROBINSON Evolution of N Simple Chromophore Shape Modification  Loading  First Multi- Chromophore Dendrimer

16. ROBINSONROBINSON Translating Microscopic to Macroscopic Electro-Optic Activity

17. ROBINSONROBINSON Analytic Theories for Spheroidal Dipoles

18. ROBINSONROBINSON Monte Carlo Calculations Use Monte Carlo methods to determine the effect of dipolar interactions between chromophores. A 5 by 5 two dimensional array Randomly oriented dipoles Place dipoles on a grid (simple cubic lattice and body centered cubic lattice) M by M by M array with r as nearest neighbor distance.

19. ROBINSONROBINSON How Monte Carlo Works Choose a dipole Rotate dipole by: a rotation axis and angle, selected randomly Compare the energy before and after rotation. If the energy is lower, keep the move If the energy is higher, compare Boltzmann Probability with a [0,1] random number, and keep if larger.

20. ROBINSONROBINSON Comparison of Potential Functions from Analytic Theory & Monte Carlo Calculations Solid Line—Analytic Theory. Points—Monte Carlo Calculation

21. ROBINSONROBINSON. Prediction of the Dependence on Poling Field

22. ROBINSONROBINSON Comparison of Theory & Experiment. Experiment—Solid Diamonds

23. ROBINSONROBINSON Lattice Geometries

24. ROBINSONROBINSON. New Strategy: Generalize the Concept of Dendronized Chromophores. Dendrimer Synthesis

25. ROBINSONROBINSON DMC3-97 NLO Chromophre

26. ROBINSONROBINSON Features of Ellipsoids Complete flexibility of Charge and Dipole Distributions Complete flexibility of Connectivity to other Ellipsoids Complete flexibility of oreintation (for Monte Carlo and Brownian Dynamics Trajectories) Polarizability Tensor Computes all electrostatics with other Ellipsoids and arbitrary External Field A contact function to find Ellipsoid-Ellipsoid interactions Can have either Hard-Shell Repulsion or Leonard-Jones Interactions Solvent free energies and exposure factors (use the rolling ball method) Can generate dendrimers, polymers and lattices of ellipsoids

27. ROBINSONROBINSON Dendrimer Performance Statistical Mechanical Theory explains the improved performance of dendritic chromophores. By choosing a tilt angle for the three chromophores (~60°) the experimental enhancement (of ~ 2 fold) was realized.

28. ROBINSONROBINSON Dendrimer Structure Original Geometry

29. ROBINSONROBINSON Three-Fold Dendrimer Three chromophores at Equilibrium With NO poling field: Nearly Planar

30. ROBINSONROBINSON Three-Fold Dendrimer Three chromophores at Equilibrium With a poling field: Constrained and Aligned

31. ROBINSONROBINSON Polymer of Dendrimers

32. ROBINSONROBINSON Lattice of Dendrimers

33. ROBINSONROBINSON Thermal Annealing

34. ROBINSONROBINSON Aspect Ratio: A Search for more order

35. ROBINSONROBINSON Aspect Ratio and Field

36. ROBINSONROBINSON Mission Possible Materials (I) The state of the art for OEO Materials: R 33 : 70 pm/V (CLD in 2000) V p : 0.8 V (2000) R 33 : 130 pm/V (2002) V p : 0.3 V (2000) Industry Standard: LiNiO 3 R 33 : 32 pm/V V p : 5 V (@40 GHz)

37. ROBINSONROBINSON Mission Possible Materials (II) Quantum Mechanical Based Improvements: Increase b : Yes, by 5-10 fold Placement of Heteroatoms; Mix Donors and Acceptors Increase m : No, not needed Already 20 Debye and will go higher anyway Statistical Mechanical Based Improvements: Improve order by 5 fold (currently order is 5%) o Design Dendrimers o Improve Steric Interactions o Place Chromophores on Polymer Backbone Improve order 20 fold o FerroElectrically ordered materials Only Theory can begin to crack this problem. The new R 33 is 130*20 = 2600 pm/V

38. ROBINSONROBINSON Mission Possible Materials (III) Engineering Based Improvements: BandWidth: Done (100+ GHz performance now) Devices are cladding limited Design Devices to be in Resonant Structures (Trade Bandwidth for V p ) Use Photonic Band-Gap Structures to obtain beam confinement and minimize the need for cladding. (Theory can predict light beam confinement)

39. ROBINSONROBINSON Light Through Regular Array

40. ROBINSONROBINSON Light Beam in Photonic Material