TY - JOUR
T1 - Spectral and angular shaping of infrared radiation in a polymer resonator with molecular vibrational modes
AU - Tsuda, Shinichiro
AU - Yamaguchi, Shuhei
AU - Kanamori, Yoshiaki
AU - Yugami, Hiroo
N1 - Funding Information:
Tohoku University Division for Interdisciplinary Advanced Research and Education (DIARE); Tohoku University Nanofabrication Platform in the Nanotechnology Platform Project sponsored by the Ministry of Education, Culture, Sports, Science and Technology.
Publisher Copyright:
© 2018 Optical Society of America.
PY - 2018
Y1 - 2018
N2 - We present a comprehensive approach for tailoring the spectral and angular properties of infrared thermal radiation by using a polymer resonator with molecular vibrational modes, consisting of a polymer thin film on a back-reflective substrate. To precisely design the resonator, we derived the infrared dielectric function of a poly(methyl methacrylate) (PMMA) thin film from the measured reflectance spectrum by fitting it with a Gaussian-convoluted Drude-Lorentz model while accounting for the inhomogeneous broadening caused by the disordered structure of polymers. Our experimental and numerical characterization confirms that the polymer resonator exhibits spectral shaping from quasi-broadband to narrowband due to the intrinsic molecular vibrational absorption of the polymer. The frequency-isolated and strong molecular vibrational absorption of the carbonyl stretching mode at 1730 cm−1 enables the narrowband shaping of the PMMA resonator. In addition, we confirm that the angular-shaping characteristics of this polymer resonator can be tuned, from omnidirectional to strongly angular selective, by changing its polymer film thickness. Modal dispersion analysis reveals that the angle-selectivity of the polymer resonator at an angle of incidence of 80° comes from coupling between the molecular vibrational mode and leaky mode. The proposed infrared radiation management strategy based on molecular vibrational modes of polymers is cost-effective, scalable, and works well with terrestrial matter, including organic compounds and gas molecules, showing promise for applications such as optical gas sensing and radiative thermal management.
AB - We present a comprehensive approach for tailoring the spectral and angular properties of infrared thermal radiation by using a polymer resonator with molecular vibrational modes, consisting of a polymer thin film on a back-reflective substrate. To precisely design the resonator, we derived the infrared dielectric function of a poly(methyl methacrylate) (PMMA) thin film from the measured reflectance spectrum by fitting it with a Gaussian-convoluted Drude-Lorentz model while accounting for the inhomogeneous broadening caused by the disordered structure of polymers. Our experimental and numerical characterization confirms that the polymer resonator exhibits spectral shaping from quasi-broadband to narrowband due to the intrinsic molecular vibrational absorption of the polymer. The frequency-isolated and strong molecular vibrational absorption of the carbonyl stretching mode at 1730 cm−1 enables the narrowband shaping of the PMMA resonator. In addition, we confirm that the angular-shaping characteristics of this polymer resonator can be tuned, from omnidirectional to strongly angular selective, by changing its polymer film thickness. Modal dispersion analysis reveals that the angle-selectivity of the polymer resonator at an angle of incidence of 80° comes from coupling between the molecular vibrational mode and leaky mode. The proposed infrared radiation management strategy based on molecular vibrational modes of polymers is cost-effective, scalable, and works well with terrestrial matter, including organic compounds and gas molecules, showing promise for applications such as optical gas sensing and radiative thermal management.
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U2 - 10.1364/OE.26.006899
DO - 10.1364/OE.26.006899
M3 - Article
C2 - 29609377
AN - SCOPUS:85044144701
VL - 26
SP - 6899
EP - 6915
JO - Optics Express
JF - Optics Express
SN - 1094-4087
IS - 6
ER -