Rational design of dramatically improved electro-optic materials

ABSTRACTA number of material properties must be optimized before organic electro-optic materials can be used for practical device applications. These include electro-optic activity, optical transparency, and stability including both thermal and photochemical stability. Exploiting an improved understanding of the structure/function relationships, we have recently prepared materials exhibiting electro-optic coefficients of greater than 50 pm/V and optical loss values of less than 0.7 dB/cm at the telecommunication wavelengths of 1.3 and 1.55 microns. When oxygen is excluded to a reasonable extent, long-term photostability to optical power levels of 20 mW has been observed. Photostability is further improved by addition of scavengers and by lattice hardening. Long-term (greater than 1000 hours) thermal stability of poling-induced electro-optic activity is also observed at elevated temperatures (greater than 80°C) when appropriate lattice hardening is used. The successful improvement of organic electro-optic materials rests upon (1) attention to the design of chromophore structure including design to inhibit unwanted intermolecular electrostatic interactions and to improve chromophore instability and (2) attention to processing conditions including those involved in spin casting, electric field poling, and lattice hardening. A particularly attractive new direction has been the exploitation of dendrimer structures and particularly of multi-chromophore containing dendrimer structures. This approach has permitted the simultaneous improvement of all material properties. Development of new materials has facilitated the fabrication of a number of prototype devices and most recently has permitted investigation of the incorporation of electro-optic materials into photonic bandgap and microresonator structures. The latter are relevant to active wavelength division multiplexing (WDM). Significant quality factors (greater than 10,000) have been realized for such devices permitting wavelength discrimination at telecommunication wavelengths of 0.01 nm.

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Acentric lattice electro-optic materials by rational design

10.1117/12.617232 ◽

2005 ◽

Cited By ~ 1

Author(s):

Larry Dalton ◽

Bruce Robinson ◽

Alex Jen ◽

Philip Ried ◽

Bruce Eichinger ◽

...

Keyword(s):

Rational Design ◽

Electro Optic

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Rational design of organic electro-optic materials

Journal of Physics Condensed Matter ◽

10.1088/0953-8984/15/20/203 ◽

2003 ◽

Vol 15 (20) ◽

pp. R897-R934 ◽

Cited By ~ 118

Author(s):

L R Dalton

Keyword(s):

Rational Design ◽

Electro Optic

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Integrated Optics/Electronics Using Electro-Optic Polymers

MRS Proceedings ◽

10.1557/proc-817-l7.2 ◽

2004 ◽

Vol 817 ◽

Cited By ~ 4

Author(s):

Larry R. Dalton

Keyword(s):

Soft Lithography ◽

Rational Design ◽

Operating Voltage ◽

Metal Electrodes ◽

Flexible Devices ◽

Systematic Improvement ◽

Electro Optic ◽

Substantial Progress ◽

New Processing ◽

Made In

AbstractOrganic electro-optic materials afford the realization of devices with terahertz bandwidths, providing bandwidths are not limited by resistive losses in metal electrodes. Recent realization of electro-optic coefficients (at telecommunication wavelengths) on the order of 200 pm/V permits construction of devices with operating voltage requirements of 1 volt or less. In like manner, substantial progress has been made in both understanding and improving thermal and photostability suggesting that organic electro-optic materials can meet Telacordia standards. However, one of the most intriguing advances afforded by organic materials is their processability including the ability to be integrated with diverse materials. This communication discusses both the systematic improvement, by theoretically-inspired rational design, of relevant material properties and the development of a variety of new processing methodologies, including soft lithography methods, for the fabrication of stripline, cascaded prism, and ring microresonator devices. The fabrication of flexible devices is also discussed.

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Epitaxial ferroelectric thin films

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100170591 ◽

1994 ◽

Vol 52 ◽

pp. 572-573

Author(s):

S. G. Ghonge ◽

E. Goo ◽

R. Ramesh ◽

R. Haakenaasen ◽

D. K. Fork

Keyword(s):

Single Crystal ◽

Work Function ◽

Nonvolatile Memory ◽

Ferroelectric Properties ◽

Electrical Contact ◽

Memory Devices ◽

Ferroelectric Films ◽

Si Substrates ◽

Electro Optic ◽

Wide Range

Microstructure of epitaxial ferroelectric/conductive oxide heterostructures on LaAIO3(LAO) and Si substrates have been studied by conventional and high resolution transmission electron microscopy. The epitaxial films have a wide range of potential applications in areas such as non-volatile memory devices, electro-optic devices and pyroelectric detectors. For applications such as electro-optic devices the films must be single crystal and for applications such as nonvolatile memory devices and pyroelectric devices single crystal films will enhance the performance of the devices. The ferroelectric films studied are Pb(Zr0.2Ti0.8)O3(PLZT), PbTiO3(PT), BiTiO3(BT) and Pb0.9La0.1(Zr0.2Ti0.8)0.975O3(PLZT).Electrical contact to ferroelectric films is commonly made with metals such as Pt. Metals generally have a large difference in work function compared to the work function of the ferroelectric oxides. This results in a Schottky barrier at the interface and the interfacial space charge is believed to responsible for domain pinning and degradation in the ferroelectric properties resulting in phenomenon such as fatigue.

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Molecular insights on the dynamic stability of peptide nucleic acid functionalized carbon and boron nitride nanotubes

Physical Chemistry Chemical Physics ◽

10.1039/d0cp05759b ◽

2021 ◽

Vol 23 (1) ◽

pp. 219-228

Author(s):

Nabanita Saikia ◽

Mohamed Taha ◽

Ravindra Pandey

Keyword(s):

Nucleic Acid ◽

Boron Nitride ◽

Nucleic Acids ◽

Dynamic Stability ◽

Peptide Nucleic Acid ◽

Rational Design ◽

Peptide Nucleic Acids ◽

Boron Nitride Nanotubes ◽

Molecular Hybrids ◽

Single Wall Nanotubes

The rational design of self-assembled nanobio-molecular hybrids of peptide nucleic acids with single-wall nanotubes rely on understanding how biomolecules recognize and mediate intermolecular interactions with the nanomaterial's surface.

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