The Appeal of Small Molecules for Practical Nonlinear Optics. Issue 6 (2nd December 2021)

• Record Type: Journal Article
• Authors: Biaggio, Ivan
• Is Part Of: Chemistry. Volume 28:Issue 6(2022)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2021-12-02
• Subjects: donor-acceptor substitution -- electro optics -- integrated optics -- monolithic molecular assemblies -- nonlinear optics -- photonics -- vapor deposition; Chemistry -- Periodicals; 540
• DOI: 10.1002/chem.202103168
• Languages: English
• ISSNs: 0947-6539

Abstract

Abstract: Small organic molecules with a π‐conjugated system that consists of only a few double or triple bonds can have significantly smaller optical excitation energies when equipped with donor and acceptor groups, which raises the quantum limits to the molecular polarizabilities. As a consequence, third‐order nonlinear optical polarizabilities become orders of magnitude larger than those of molecules of similar size without donor‐acceptor substitution. This enables strong third‐order nonlinear optical effects (as high as 1000 times those of silica glass) in dense, amorphous monolithic assemblies. These properties, accompanied by the possibility of deposition from the vapor phase and of electric‐field poling at higher temperatures, make the resulting materials competitive towards adding an active nonlinear optical or electro‐optic functionality to state‐of‐the‐art integrated photonics platforms. Abstract : Donor‐acceptor substitution in small molecules with a compact π‐conjugated system leads to record‐high molecular nonlinearities in small sizes. A dense monolithic assembly of such molecules can have extraordinarily strong nonlinear optical properties. The ability to vapor deposit such small molecule materials makes them highly competitive for adding all‐optical switching and/or electro‐optic functionality to state‐of‐the‐art integrated photonics.