Free-standing, flexible thermochromic films based on one-dimensional magnetic photonic crystals

2015 ◽  
Vol 3 (12) ◽  
pp. 2848-2855 ◽  
Author(s):  
Huiru Ma ◽  
Mingxing Zhu ◽  
Wei Luo ◽  
Wei Li ◽  
Kai Fang ◽  
...  

Instant radical polymerization of sterically stabilized magnetically responsive photonic crystal nonaqueous suspensions under magnetic field can obtain flexible thermochromic free-standing films, which display bright iridescent colors strongly sensitive to temperature with good reversibility and durability.

Author(s):  
Azka Umar ◽  
Chun Jiang

This paper focuses on manipulating thermal emission and radiation loss of heat energy in a heat waveguide. A One-Dimensional Photonic Crystal is used as a waveguide clad to prohibit the thermal emission from escaping. The model may reduce the radiation loss of heat energy in the waveguide core, and heat energy can be confined to propagate along the waveguide’s longitude axis. The waveguide clad comprises alternative layers of high and low refractive index materials containing sufficient electromagnetic stop bands to trap the thermal emission from escaping out of the waveguide. The numerical simulation of the model shows that the forbidden bandgap of photonic crystal structures with alternative layers of silica and silicon has width enough to make heat energy be confined within the waveguide core so that efficient heat energy transmission can be achieved along the longitude axis of the waveguide.


2020 ◽  
Vol 12 (36) ◽  
pp. 40979-40984 ◽  
Author(s):  
Cihui Liu ◽  
Lulu Zhang ◽  
Xinran Zhang ◽  
Yizhen Jia ◽  
Yunsong Di ◽  
...  

2008 ◽  
Vol 8 (12) ◽  
pp. 6584-6588 ◽  
Author(s):  
R. Márquez-Islas ◽  
B. Flores-Desirena ◽  
F. Pérez-Rodríguez

We investigate theoretically the coupling of exciton with light in a one-dimensional photonic crystal. The unit cell of the crystal consists of two alternating layers, namely a metallic layer and a semiconductor one. The frequency-dependent dielectric function of the metal is described by the Drude model, whereas for the semiconductor we use a nonlocal excitonic dielectric function. The polariton dispersion for s-polarized modes in the metal-semiconductor photonic crystal is compared with that for a dielectric-semiconductor photonic crystal. Because of the metal layers, a low-frequency gap appears in the photonic band structure. The presence of the semiconductor gives rise to photonic bands associated with the coupling of light with size-quantized excitón states. At frequencies above the longitudinal exciton frequency, the photonic band structure exhibits anticrossing phenomena produced by the upper exciton–polariton mode and size-quantized excitons. It is found that the anticrossing phenomena in the metal-semiconductor photonic crystal occur at higher frequencies in comparison with the dielectric-semiconductor case.


2021 ◽  
Vol 2015 (1) ◽  
pp. 012022
Author(s):  
A A Bragina ◽  
K R Safronov ◽  
V O Bessonov ◽  
A A Fedyanin

Abstract In this work, we numerically study the luminescence of nanodiamonds with NV centres embedded in a polymer layer on the surface of one-dimensional photonic crystal. The interaction of NV center spontaneous emission with the Bloch surface wave (BSW) is demonstrated. The presence of a photonic crystal leads to a change in the angular distribution of the emitter radiation due to the coupling of luminescence to BSW. We show that the best coupling efficiency of 71% is observed when NV centres are located in the close proximity to the BSW field maximum.


Optics ◽  
2021 ◽  
Vol 2 (4) ◽  
pp. 284-291
Author(s):  
Victoria Paige Stinson ◽  
Serang Park ◽  
Micheal McLamb ◽  
Glenn Boreman ◽  
Tino Hofmann

One-dimensional photonic crystals composed of alternating layers with high- and low-density were fabricated using two-photon polymerization from a single photosensitive polymer for the infrared spectral range. By introducing single high-density layers to break the periodicity of the photonic crystals, a narrow-band defect mode is induced. The defect mode is located in the center of the photonic bandgap of the one-dimensional photonic crystal. The fabricated photonic crystals were investigated using infrared reflection measurements. Stratified-layer optical models were employed in the design and characterization of the spectral response of the photonic crystals. A very good agreement was found between the model-calculated and measured reflection spectra. The geometric parameters of the photonic crystals obtained as a result of the optical model analysis were found to be in good agreement with the nominal dimensions of the photonic crystal constituents. This is supported by complimentary scanning electron microscope imaging, which verified the model-calculated, nominal layer thicknesses. Conventionally, the accurate fabrication of such structures would require layer-independent print parameters, which are difficult to obtain with high precision. In this study an alternative approach is employed, using density-dependent scaling factors, introduced here for the first time. Using these scaling factors a fast and true-to-design method for the fabrication of layers with significantly different surface-to-volume ratios. The reported observations furthermore demonstrate that the location and amplitude of defect modes is extremely sensitive to any layer thickness non-uniformities in the photonic crystal structure. Considering these capabilities, one-dimensional photonic crystals engineered with defect modes can be employed as narrow band filters, for instance, while also providing a method to quantify important fabrication parameters.


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