We report femtosecond light-induced macromolecular self-assembly (FLIMSA), which is observed when a high peak intensity femtosecond laser beam propagates through aqueous solution of pseudoisocyanine iodide (PIC) J-aggregates and induces the formation of 0.1 – 1.0 mm-size tube-like structure surrounding the laser beam, while at the same time allowing the beam to continue propagating without obstruction or scattering. The FLIMSA material is morphologically heterogeneous and gel-like and is formed at the margins rather than at the center of the beam. As a potential explanation of this effect we assume that the FLIMSA is induced by the high photon flux gradient characteristic of the femtosecond laser beam periphery. This hypothesis is corroborated by control experiments, where J-aggregate samples were illuminated with nanosecond laser sources with a varying pulse duration, power- and beam shape characteristics, but where no FLIMSA formation was observed.

Date Published: 23 September 2016
PDF: 7 pages
Proc. SPIE 9939, Light Manipulating Organic Materials and Devices III, 99390D (23 September 2016); doi: 10.1117/12.2237867

Published in SPIE Proceedings Vol. 9939:
Light Manipulating Organic Materials and Devices III
Joy E. Haley; Jon A. Schuller; Manfred Eich; Jean-Michel Nunzi, Editor(s)