scholarly journals Perfect Optical Absorbers by All-Dielectric Photonic Crystal/Metal Heterostructures Due to Optical Tamm State

Nanomaterials ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 3447
Author(s):  
Guang Lu ◽  
Kaiyuan Zhang ◽  
Yunpeng Zhao ◽  
Lei Zhang ◽  
Ziqian Shang ◽  
...  

In this study, we theoretically and experimentally investigated the perfect optical absorptance of a photonic heterostructure composed of a truncated all-dielectric photonic crystal (PC) and a thick metal film in the visible regions. The three simulated structures could achieve narrow-band perfect optical absorption at wavelengths of 500 nm, 600 nm, and 700 nm, respectively. Based on the measured experimental results, the three experimental structures achieved over 90% absorption at wavelengths of 489 nm, 604 nm, and 675 nm, respectively. The experimental results agreed well with the theoretical values. According to electromagnetic field intensity distributions at the absorption wavelengths, the physical mechanism of perfect absorption was derived from the optical Tamm state (OTS). The structure was simple, and the absorption characteristics were not significantly affected by the thickness of the thick metal layer, which creates convenience in the preparation of the structure. In general, the proposed perfect absorbers have exciting prospects in solar energy, optical sensor technology, and other related fields.

2015 ◽  
Vol 42 (11) ◽  
pp. 1114001
Author(s):  
陈颖 Chen Ying ◽  
董晶 Dong Jing ◽  
刘腾 Liu Teng ◽  
石佳 Shi Jia ◽  
朱奇光 Zhu Qiguang ◽  
...  

2016 ◽  
Vol 30 (04) ◽  
pp. 1650030 ◽  
Author(s):  
Ying Chen ◽  
Jing Dong ◽  
Teng Liu ◽  
Qiguang Zhu ◽  
Weidong Chen

A photonic crystal’s refractive index sensor is proposed based on the photonic crystal (PC) optical properties and the surface wave resonance principle. The optical Tamm state existing at the interface between one-dimensional (1D) PCs and the metal layer can overcome the disadvantage of the surface plasmon resonance (SPR) sensor in which the incident light can only be TM polarized light. The resonant wavelength can be changed by adjusting the optical parameters of the PC. Through coating the metal surface with graphene, the resolution and sensitivity of the sensor can be improved obviously. The relationship model between the graphene parameters and the reflectivity is established by analyzing the reflective properties of the graphene. In the numerical simulation, the graphene layer is optimized to improve the refractive index sensing properties. The numerical simulation results show that the quality factor ([Formula: see text] value) can attain to 1418.2 and the sensitivity is about 1178.6 nm RIU[Formula: see text], which can demonstrate the effectiveness of the senor structure and provide some theoretical references for the design of the refractive index sensors with high [Formula: see text] value and sensitivity.


Nanomaterials ◽  
2020 ◽  
Vol 11 (1) ◽  
pp. 63
Author(s):  
Zhendong Yan ◽  
Chaojun Tang ◽  
Guohua Wu ◽  
Yumei Tang ◽  
Ping Gu ◽  
...  

Achieving perfect electromagnetic wave absorption with a sub-nanometer bandwidth is challenging, which, however, is desired for high-performance refractive-index sensing. In this work, we theoretically study metasurfaces for sensing applications based on an ultra-narrow band perfect absorption in the infrared region, whose full width at half maximum (FWHM) is only 1.74 nm. The studied metasurfaces are composed of a periodic array of cross-shaped holes in a silver substrate. The ultra-narrow band perfect absorption is related to a hybrid mode, whose physical mechanism is revealed by using a coupling model of two oscillators. The hybrid mode results from the strong coupling between the magnetic resonances in individual cross-shaped holes and the surface plasmon polaritons on the top surface of the silver substrate. Two conventional parameters, sensitivity (S) and figure of merit (FOM), are used to estimate the sensing performance, which are 1317 nm/RIU and 756, respectively. Such high-performance parameters suggest great potential for the application of label-free biosensing.


2011 ◽  
Vol 383-390 ◽  
pp. 5211-5215
Author(s):  
Yin Lin Li ◽  
Zhong Hua Huang ◽  
Kai Bo Hu

A novel refractometer based on photoelectric sensor technology and differential method is proposed. Sensing principle and mathematical model are introduced; structure and key parameters of sensing probe are designed through detail calculation. Theoretical solution shows resolution reaches order of 10-5. Preliminary experiments verify the feasibility of the design, experimental results show stability error better than ±1.02×10-4, error caused by temperature is 6.65×10-6/°C.


2015 ◽  
Vol 723 ◽  
pp. 737-741
Author(s):  
Xu Guang Yu ◽  
Zhong Yuan Yu ◽  
Yu Min Liu

We present a finite element method to analyze the spontaneous emission of a single quantum dot in photonic crystal slabs. Through changing the geometry of the photonic crystal slabs and the position of the quantum dot the spontaneous emission can be funneled into a mode that we desired efficiently. Different photonic crystal cavities and waveguides are demonstrated. The physical mechanism of this phenomenon is discussed and the application prospects of this design are proposed.


2019 ◽  
Vol 9 (7) ◽  
pp. 1410 ◽  
Author(s):  
Tao Chen ◽  
Runyu Zhao ◽  
Ben-Xin Wang

This paper presents a simple metamaterial design to achieve the triple-band near-perfect absorption response that can be used in the area of sensor application. The introduced absorber consists of an array of Au strip and a bulk flat Au film separated by an insulator dielectric layer. Three narrow-band resonance absorption peaks are obtained by superposing three different modes (a fundamental mode resonance and two high-order responses) of the Au strip. These resonance modes (in particular of the last two modes) have large sensitivity to the changes of the surrounding index, overlayer thickness and the refractive index of the overlayer.


2018 ◽  
Vol 27 (01) ◽  
pp. 1850004 ◽  
Author(s):  
Shu Jing Liu ◽  
Cong Zhang ◽  
Ruiping Bai ◽  
Xintong Gu ◽  
Hong Da Yin ◽  
...  

We demonstrate the unidirectional reflectionlessness at exceptional points (EPs) and nonreciprocal perfect absorption near EPs based on phase coupling between two photonic crystal cavities (PCCs) in optical waveguide. In our scheme, when distance [Formula: see text][Formula: see text]nm ([Formula: see text][Formula: see text]nm), the reflectivities for forward and backward (backward and forward) directions are closed to [Formula: see text] and [Formula: see text] ([Formula: see text] and [Formula: see text]), respectively, and absorptances of the nonreciprocal perfect absorptions for forward and backward directions are [Formula: see text] and [Formula: see text] with the high quality factors of [Formula: see text] and [Formula: see text], respectively.


Author(s):  
Riaz A. Mufti ◽  
Martin Priest

Bench testing can provide rapid and cost effective information for developing new lubricants. But there is general agreement that the only satisfactory means of evaluating the behaviour of engine oil is by actual use in engine. Also for detailed analysis of the tribological interaction it is important to analyse the engine performance at the component level. With the help of advance data acquisition system and sensor technology, experimental measurement of friction losses at the component level have been measured at realistic engine operating conditions, using the technique explained in Part 1. This paper describes the outcome of the experimental results at a range of engine operating conditions using mainly SAE 0W20 lubricant and some results from a friction-modified SAE 5W30 lubricant. The results clearly show considerable changes in the percentage contribution of power loss between low and high lubricant temperatures. The change in mode of lubricating regime from boundary to fluid film lubrication can be seen at the component level with increase in engine speed and decrease in lubricant temperature. This system can be used as a powerful tool for screening engine oils, analysing component design, validating friction models and studying the effect of different additives on the performance of each component under realistic operating conditions.


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