Open AccessFemtosecond laser irradiation of molecular excitonic films for nanophotonic response control and large-area patterning
Author(s) -
Byung Hoon Woo,
Yejin Son,
Jiyeon Choi,
Sangmin Chae,
Hyo Jung Kim,
Young Chul Jun
Publication year - 2019
Publication title -
optics express
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.394
H-Index - 271
ISSN - 1094-4087
DOI - 10.1364/oe.27.018044
Subject(s) - femtosecond , materials science , laser , nanophotonics , optics , optoelectronics , plasmon , dielectric , irradiation , thin film , nanotechnology , physics , nuclear physics
Molecular excitonic films such as J-aggregate thin films can show an optically metallic response in the visible region and can be considered as alternative materials for plasmonics. However, there was no direct, top-down method to modify the optical response over a large area. Here, we demonstrate the femtosecond (fs) laser processing of J-aggregate films on the centimeter scale. With proper laser conditions, optically metallic films (Re[ε] < 0) were modified to dielectric ones (Re[ε] > 0) with large changes in optical responses. We performed various optical spectrum measurements to investigate the effect of fs-laser irradiation. Our results demonstrate that the strong modification of the optical response can be induced over a large area by fs-laser processing and this can be useful for novel nanophotonic studies.