TY - JOUR
T1 - Exploiting Zone-Folding Induced Quasi-Bound Modes to Achieve Highly Coherent Thermal Emissions
AU - Sun, Kaili
AU - Levy, Uriel
AU - Han, Zhanghua
N1 - Publisher Copyright:
© 2024 American Chemical Society.
PY - 2024/1/17
Y1 - 2024/1/17
N2 - Thermal emissions with high coherence, although not as high as those of lasers, still play a crucial role in many practical applications. In this work, by exploiting the geometric perturbation-induced optical lattice tripling and the associated Brillion zone folding effect, we propose and investigate thermal emissions in the mid-infrared with simultaneous high temporal and spatial coherence. In contrast with the case of period-doubling perturbation in our previous work, the steeper part of the guided mode dispersion band will be folded to the high-symmetry Γ point in the ternary grating. In this case, a specific emission wavelength corresponds to only a very small range of wavevectors. Consequently, apart from the high temporal coherence characterized by an experimental bandwidth around 30 nm, the achieved thermal emissions also feature ultrahigh spatial coherence. Calculations show that at the thermal emission wavelengths in the mid-infrared, the spatial coherence length can easily reach up to mm scale.
AB - Thermal emissions with high coherence, although not as high as those of lasers, still play a crucial role in many practical applications. In this work, by exploiting the geometric perturbation-induced optical lattice tripling and the associated Brillion zone folding effect, we propose and investigate thermal emissions in the mid-infrared with simultaneous high temporal and spatial coherence. In contrast with the case of period-doubling perturbation in our previous work, the steeper part of the guided mode dispersion band will be folded to the high-symmetry Γ point in the ternary grating. In this case, a specific emission wavelength corresponds to only a very small range of wavevectors. Consequently, apart from the high temporal coherence characterized by an experimental bandwidth around 30 nm, the achieved thermal emissions also feature ultrahigh spatial coherence. Calculations show that at the thermal emission wavelengths in the mid-infrared, the spatial coherence length can easily reach up to mm scale.
KW - Brillion zone-folding
KW - coherent thermal emitters
KW - mid-infrared
KW - quasi-guided mode
KW - ternary grating
UR - http://www.scopus.com/inward/record.url?scp=85181581365&partnerID=8YFLogxK
U2 - 10.1021/acs.nanolett.3c04587
DO - 10.1021/acs.nanolett.3c04587
M3 - ???researchoutput.researchoutputtypes.contributiontojournal.article???
C2 - 38166141
AN - SCOPUS:85181581365
SN - 1530-6984
VL - 24
SP - 764
EP - 769
JO - Nano Letters
JF - Nano Letters
IS - 2
ER -