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Optical fiber communication and sensitivity
Published in Muhammad Arif, Guojun Wang, Mazin Abed Mohammed, Md Tabrez Nafis, Vehicular Ad Hoc Networks, 2023
Salma Masuda Binta, Mohammed Hossam-E Haider, Mohammad Farhan Ferdous
Mainly, the working process of SPR-based photonic crystal sensor depends on the evanescent field [21]. To maximize the sensitivity and lessen the fabrication challenge are the purposes of this design. Here, a dual core is placed at the two opposite sides of the elliptical air hole. The advantage of a dual-core sensor over a single-core sensor is that the evanescent field can easily reach the metal surface and excite the electron effectively. So, to reduce the distance between the metal surface and evanescent field dual core is introduced. It is also noted that the small diameter of the air hole in the horizontal direction confirms the generation of SPW. The background material of the sensor is fused silica that is characterized by the Sllmeier equation [22]. The fabrication of the designed PCF sensor is done by the stack and draw technique [23]. Then, gold (plasmonic material) is deposited outside of the PCF by the chemical vapor deposition technique [24]. The plasmonic material gold is characterized by the Drude–Lorentz model [25]. ε(ω)=ε1+iε2=ε∞ωp2ω(ω+iωc)
Designing and technical analysis of the use of combination of PhCs based hydrogel with an enzyme hydrogel as biosensors
Published in Khaled Habib, Elfed Lewis, Frontier Research and Innovation in Optoelectronics Technology and Industry, 2018
Fenzl et al (2014) have reported on a method for selective optical sensing and imaging of potassium ions using a sandwich assembly composed of layers of photonic crystals and an ion-selective membrane, which in fact represents a new scheme for sensing ions in that an ionic strength-sensitive photonic crystal hydrogel layer is combined with a K+-selective membrane, the latter being consisting of plasticized poly(vinyl chloride) doped with the K+-selective ion carrier, valinomycin. It has been observed that the film has a red color, if immersed into plain water, but is green in 5 mM KCl, and purple at KCl concentrations of 100 mM or higher. It has been emphasized that this 3D photonic crystal sensor responds to K+ ions in the 1 to 50 mM concentration range, which includes the K+ concentration range encountered in blood, and shows high selectivity over ammonium and sodium ions. Sensor films have also been imaged with a digital camera for studying the effect of the salt concentration on the wavelength of the reflected light of colloidal PhCs in a hydrolyzed PAM hydrogel covered with a K+-selective membrane. The film is immersed into solutions of KCl, KNO3, NaCl and NH4Cl of varying concentrations. From the results of Fenzl et al (2014), it has been verified that for the Potasium compounds, the reflected wavelength/nm falls quite rapidly at salt concentration higher than 10=3 mol-L=1. However, for sodium and Ammonium compounds, it remains nearly constant.
Side-coupled nanoscale photonic crystal structure with high-Q and high-stability for simultaneous refractive index and temperature sensing
Published in Journal of Modern Optics, 2019
Zhiqiang Liu, Fujun Sun, Chao Wang, Huiping Tian
In the field of sensing, temperature detection is a very common and critical parameter, and high sensitivity temperature sensor with small volume is demanded in many scenarios. Therefore, we have conducted a temperature test with the photonic crystal sensor that we designed. The temperature feedback of the photonic crystal is different from the RI of the surrounding materials, the temperature changes will make the photonic crystal slabs and the surrounding materials simultaneously change, yet the RI of the surrounding materials will not. The thermos-optic coefficient of air is about 10−7/K (20), the RI variation induced by thermo-optic effect is too small to be significant. In this paper, the thermo-optic coefficient of silicon is set as 1.8 10−4/K (21), which is the key to temperature detection.