Push-Pull Organic Chromophores for Frequency-Upconverted Lasing

• Published in: Advanced materials (Weinheim) Vol. 12; no. 24; pp. 1963 - 1967
• Main Authors: Abbotto, A., Beverina, L., Bozio, R., Bradamante, S., Ferrante, C., Pagani, G. A., Signorini, R.
• Format: Journal Article
• Language: English
• Published: Weinheim WILEY-VCH Verlag GmbH 01.12.2000; WILEY‐VCH Verlag GmbH
• Subjects: Chromophores; Donor-Acceptor Systems; Frequency Upconversion; Laser
• ISSN: 0935-9648; 1521-4095
• DOI: 10.1002/1521-4095(200012)12:24<1963::AID-ADMA1963>3.0.CO;2-S

Properly designed organic molecules where a π‐conjugated bridge is end‐capped by an electron‐donor and electron‐withdrawing group (push–pull chromophores) can show, under specific conditions, frequency‐upconverted lasing emission. Materials based on these dyes are therefore able to convert the emission of a cheap and easily available infrared (IR) laser (e.g., 800 nm radiation) into more useful visible (vis) laser emission via a two‐photon absorption induced fluorescence phenomenon. The design of the molecular structure, the substituent effect, and modulation of the electronic and geometric parameters can be used in order to optimize and tune frequency emission and conversion efficiency. Examples of some of the best dyes reported to‐date and organic design strategies employed are discussed in this article. Organic materials capable of converting infrared wavelength laser light into visible wavelength laser light are described. The molecular and electronic structures of “push–pull”, donor–acceptor systems, such as that shown in the figure, can be tuned by appropriate substitution of the ring systems to allow the conversion efficiencies and the emission wavelengths of the systems to be optimized.