Tunable and Sensitive Refractive Index Sensors by Plasmonic Absorbers with Circular Arrays of Nanorods and Nanotubes for
- PDF / 1,465,849 Bytes
- 10 Pages / 595.276 x 790.866 pts Page_size
- 11 Downloads / 205 Views
Tunable and Sensitive Refractive Index Sensors by Plasmonic Absorbers with Circular Arrays of Nanorods and Nanotubes for Detecting Cancerous Cells Mohammad Reza Rakhshani 1 Received: 28 May 2020 / Accepted: 15 July 2020 # Springer Science+Business Media, LLC, part of Springer Nature 2020
Abstract In this paper, for improving the refractive index sensitivity, we propose different sensor devices by optical metamaterial nanoabsorbers. The presented absorbers are designed by different configurations such as basic model, nanorods, and nanotube array. With three-dimensional finite difference time domain (FDTD) method, their absorption, transmission, and reflection spectra, and sensitivity and figure of merit (FOM) values are numerically investigated. The simulation results show that the resonances at longer wavelengths have higher values of sensitivity and FOM. For presenting the applicability, we examine the sensor for detecting cancerous cells. The proposed absorbers have been coated with an outer material with a thickness of 100 nm and refractive indices of 1 1.2. The maximum sensitivity is obtained at 1055 nm/RIU for the absorber with nanotube array, while its FOM is 19.5 RIU−1. Due to its spectral characteristics, the proposed structures can be used to detect other materials such as human blood group, ethanol, and hemoglobin concentrations of some materials. Keywords Plasmonic sensor . Metamaterial absorber . Cancer sensor . Sensitivity
Introduction A blackbody soaks up all the electromagnetic radiation that illuminates it. It is an ideal absorber that no radiation passes through it and none is reflected [1]. The high absorption bodies have attracted scientist’s attention in both science and practical applications in both on-chip and off-chip devices such as sensors [2], photovoltaic applications [3] in visible and infrared [4, 5], terahertz [6], and microwave spectral regions [7]. With reduced micro-structures to nanostructures or decreasing the wavelength, the light/matter interaction can be increased and give rise to a wide variety of exciting properties [8]. Engineering spectral properties of light (absorption, reflection, and transmission) have been broadly recognized by manipulating the wave responses [9]. Surface plasmons (SPs) that formed on the metal/dielectric interface are the means of overcoming the optical diffraction limit [10]. They have wide applications in optoelectronics, especially in waveguides [11], detectors [12, 13], absorbers * Mohammad Reza Rakhshani [email protected] 1
Faculty of Engineering, University of Zabol, P. O. Box, Zabol 98613-35856, Iran
[14], and sensors [15–20]. With this notable progress, different sensing applications such as biosensors to detect blood glucose [21], blood groups [22], refractive index [23], temperature [24], and other kinds [25, 26] have been highly developed. Based on the plasmonic nanostructures, perfect absorbers have been developed these years and widely used for sensing [27, 28]. In metal nanostructures, it is possible to control the absorption and
Data Loading...
