Organic Electro-Optic Chromophores with Superior Hyperpolarizability

NU 2005-019

Inventors

Hu Kang

Tobin Marks*

Abstract

Northwestern researchers have developed a series of unconventional twisted œÄ-electron system electro-optic (EO) chromophores with ultra-large first hyperpolarizabilities. Molecule-based EO materials are of great interest for optoelectronic and photonic applications. EO response is governed by the second-order susceptibility tensor, which in turn is determined by contributions from both the net polar order and microscopic molecular first hyperpolarizability tensor (Œ=). Synthetic efforts to maximize Œ= have generally employed conjugated œÄ donor-acceptor (D/A) end-capped systems of increasing complexity. This new technology utilizes a new structural model in order to create material with significantly greater Œ= in a direct synthetic scheme. They developed a direct route to synthesize organic molecular chromophores that have the largest known electric field-induced second harmonic generation nonresonance values. More specifically, they created zwitterionic twisted œÄ-electron systems joining D/A substituents with tunable hyperpolarizability and linear optical energy. These compounds exhibited high thermal stability (Td >300¬8C), zwitterionic ground states and extraordinary molecular hyperpolarizability properties. These unusually large values portend significant performance enhancements in optoelectronic and photonic devices utilizing molecular hyperpolarizability. The synthetic scheme employed provides wide molecular variation and property modification.

Applications

• High-speed optical communications
• Integrated optics
• Optical data processes and storage

Advantages

• Possesses largest known electric field-induced second harmonic generation nonresonance values
• Tunable molecular hyperpolarizability
• Linear optical energy
• High thermal stability

IP Status

Issued US Patents No. 7,968,016 and 7,824,582