@article{1b66ae2a1ec1450aa685428f54d5b31a,
title = "Natural Hyperbolic Dispersion with Anisotropic Epsilon-Near-Zero and Epsilon-Near-Pole in Squaraine Molecular Film",
abstract = "Epsilon-near-zero (ENZ) optical material has been employed in a number of novel linear and nonlinear optical applications, owing to the vanishing polarization upon an incident optical wave. In a uniaxial medium possessing hyperbolic energy–momentum dispersion of optical wave, ENZ can take place at ordinary and extraordinary permittivities. Organic thin films presenting a lamellar structure have been reported to exhibit a transverse negative hyperbolic dispersion with ENZ at ordinary permittivity. Here, organic thin film with ENZ at extraordinary permittivity is demonstrated. Newly synthesized polymethine dye (i.e., squaraine indolenine triethyleneglycol molecule) self-organizes to form a layered structure in a pristine film, and both transverse negative and positive hyperbolic dispersions are observed at visible wavelengths. Analysis of tens-nanometer-thick pristine film shows that both ENZ and epsilon-near-pole (ENP) occur at longitudinal as well as transverse component of dielectric permittivity. Optical characterization of squaraine pristine film is presented, and the importance of transverse positive hyperbolic dispersion in such monolithic thin film is discussed.",
keywords = "epsilon-near-pole, epsilon-near-zero, hyperbolic dispersion, polymethine dye",
author = "Minjae Kim and Choi, {Kyu Ri} and Lee, {Yeon Ui} and Beno{\^i}t Heinrich and Ko, {Soo Young} and Fabrice Mathevet and Ribierre, {Jean Charles} and Anthony D'Al{\'e}o and Wu, {Jeong Weon} and Virginie Placide",
note = "Funding Information: This work was supported by funding of the Ministry of Science, ICT & Future Planning, Korea (2014M3A6B3063708, 2017R1E1A1A01075394). Y.U.L. acknowledges National Research Foundation for funding (2021R1F1A1062916). This work was carried out in the framework of CNRSUMI2002 2B‐FUEL “Building Blocks for Future Electronics Laboratory”. The authors further thank Pohang Accelerator Laboratory (PAL) for giving the opportunity to perform the GIWAXS measurements, MEST, and POSTECH for supporting these experiments, Dr. Hyungju Ahn for adjustments and help, and other colleagues from the 9A USAXS beamline for assistance. Part of this work was also supported by the CNRS (PICS No. 8085), France. The authors thank reviewers for highly valuable comments. Funding Information: This work was supported by funding of the Ministry of Science, ICT & Future Planning, Korea (2014M3A6B3063708, 2017R1E1A1A01075394). Y.U.L. acknowledges National Research Foundation for funding (2021R1F1A1062916). This work was carried out in the framework of CNRSUMI2002 2B-FUEL “Building Blocks for Future Electronics Laboratory”. The authors further thank Pohang Accelerator Laboratory (PAL) for giving the opportunity to perform the GIWAXS measurements, MEST, and POSTECH for supporting these experiments, Dr. Hyungju Ahn for adjustments and help, and other colleagues from the 9A USAXS beamline for assistance. Part of this work was also supported by the CNRS (PICS No. 8085), France. The authors thank reviewers for highly valuable comments. Publisher Copyright: {\textcopyright} 2021 Wiley-VCH GmbH",
year = "2021",
month = nov,
day = "18",
doi = "10.1002/adom.202101091",
language = "English",
volume = "9",
journal = "Advanced Optical Materials",
issn = "2195-1071",
publisher = "John Wiley & Sons Inc.",
number = "22",
}