## 2021年  14卷  第5期

2021, 14(5): 1039-1055. doi: 10.37188/CO.2021-0003

2021, 14(5): 1056-1068. doi: 10.37188/CO.2021-0071

2021, 14(5): 1069-1088. doi: 10.37188/CO.2021-0044

2021, 14(5): 1089-1103. doi: 10.37188/CO.2021-0022

2021, 14(5): 1104-1119. doi: 10.37188/CO.2021-0033

2021, 14(5): 1120-1132. doi: 10.37188/CO.2021-0125

2021, 14(5): 1133-1145. doi: 10.37188/CO.2020-0216

2021, 14(5): 1146-1161. doi: 10.37188/CO.2021-0032

2021, 14(5): 1162-1168. doi: 10.37188/CO.2021-0001

2021, 14(5): 1169-1176. doi: 10.37188/CO.2021-0005

2021, 14(5): 1177-1183. doi: 10.37188/CO.2021-0020

2021, 14(5): 1184-1193. doi: 10.37188/CO.2020-0218

2021, 14(5): 1194-1201. doi: 10.37188/CO.2020-0220

2021, 14(5): 1202-1211. doi: 10.37188/CO.2020-0214

2021, 14(5): 1212-1223. doi: 10.37188/CO.2020-0219

2021, 14(5): 1224-1230. doi: 10.37188/CO.2021-0008

2021, 14(5): 1231-1242. doi: 10.37188/CO.2020-0129

2021, 14(5): 1243-1250. doi: 10.37188/CO.2021-0018

2021, 14(5): 1251-1258. doi: 10.37188/CO.2020-0068

Optical properties of periodic double-well potential are one of the frontier research fields in laser physics and quantum optics. In this work, we have employed time-periodic double-well potential for the investigation of Fano-type resonant tunneling of photon-assisted Dirac electrons in a graphene system. Using a double quantum well structure, it is found that the resonant tunneling of electrons in a thin barrier between the two quantum wells splits the bound state energy levels, and the Fano-type resonance spectrum splits into two asymmetric resonance peaks. The shape of Fano peak is regulated by changing the phase, frequency, and amplitude, that can directly modulate the electronic transport properties of Dirac in graphene. Our numerical analysis shows that the relative phase of two oscillating fields can adjust the shape of the asymmetric Fano type resonance peak. When the relative phase increases from 0 to \begin{document}${\text{π}}$\end{document}, the resonance peak valley moves from one side of the peak to the other. In addition, the asymmetric resonance peak becomes symmetric at critical phase \begin{document}${{3{\text{π}} }/{11}}$\end{document}. Furthermore, the distribution of Fano peaks can be modulated by varying the frequency and amplitude of oscillating field and the structure of the static potential well. Finally, we suggest that these interesting physical properties can be used for the modulation of Dirac electron transport properties in graphene.
2021, 14(5): 1259-1272. doi: 10.37188/CO.2020-0204

In order to realize the demodulation of the cavity length of the fiber-optic FP sensor, a new optical wedge-type non-scanning correlation demodulation system is proposed, and the characteristics and structure of the devices used in the system are analyzed and studied. First, by simulating the light sources with different spectral distributions and the optical wedges with different surface reflectivities, the correlation interference signals are analyzed and the optimal structure parameters of the system components are given. Then by comparing the light intensity distribution characteristics of the Powell prism and cylindrical lens on the linear array CCD, more uniform spectral distribution is achieved. Finally, the specific implementation scheme and data processing method of the demodulation system are given. The experimental results show that when the light source spectrum has a Gaussian distribution and large spectral width and the reflectivity of the wedge surface is \begin{document}$R = 0.5$\end{document}, the characteristics of the correlation interference signal are obvious and convenient for demodulation. Finally, the demodulation system achieves the demodulation effect with an error of less than 0.025% within the cavity length range of 60 μm-100 μm. This optical wedge-type non-scanning correlation demodulation method can realize the sensing demodulation of the fiber-optic FP cavity and improve the power adaptability of different types of fiber-optic FP sensors.
2021, 14(5): 1273-1287. doi: 10.37188/CO.2021-0015

In order to realize the separation and release of nucleated red blood cells from peripheral blood and develop a safe and effective non-invasive technique to separate nucleated red blood cells for prenatal diagnosis of fetal diseases, an automatic cell smear preparation system based on hydrogel material was established, and a laser focusing and microscopic imaging system for recognizing and releasing nucleated red blood cells was constructed. Firstly, the mechanical structure of cell smear preparation machine was designed, the upper computer control software was designed based on single chip microcomputer, and a hydrogel membrane substrate smear was prepared by optimizing the slide-pushing angle and speed. MXene, a two-dimensional material, was introduced into temperature-sensitive hydrogel gelatin, and the near-infrared light response was realized on the surface of hydrogel membrane by using the near-infrared photothermal conversion characteristics of MXene. Then, the whole cell smear experiment was carried out on the surface of the hydrogel substrate membrane. A monolayer cell smear was prepared by optimizing the parameters of blood slide. Finally, the optical path of laser focusing and microscopic imaging was established. After the nucleated red blood cells were recognized and located, the light from an 808 nm laser source passed through a collimator lens and a convergent lens and was focused on the surface of the cell smear, which released cells under photothermal effect. A monolayer cell smear was processed and prepared, and then a photothermal effect was produced under the near-infrared light of 808 nm. After the control of the laser focusing system, a fixed cell-releasing area with a spot diameter of 300 μm was finally obtained. In this paper, the automatic slide-pushing technology was applied to the preparation of a monolayer cell smear based on hydrogel membrane, and the optical path of laser focusing and microscopic imaging was established. By using the near-infrared response and a thermal response of hydrogel membrane, the recognition and fixed-point release of nucleated red blood cells were realized, and the efficiency of separation and enrichment of nucleated red blood cells was improved. This technology has a broad application prospect in the field of prenatal screening and diagnosis.
2021, 14(5): 1288-1304. doi: 10.37188/CO.2021-0004

Compared with the commonly used simulation algorithms such as Finite Element Method (FEM) and Finite-Difference Time-Domain (FDTD) method, the Boundary Element Method (BEM) has the advantages of high accuracy, small memory consumption, and ability to deal with complex structures. In this paper, the basic principle of three-dimensional BEM is given, the corresponding program based on C++ language is written, and the Surface Plasmon Resonance (SPR) characteristics of a graphene nano-disk structure are studied. The Scattering Cross-Section (SCS) spectral lines of a graphene nano-disk under different chemical potentials, as well as the distributions of electromagnetic fields at the resonance wavelengths are calculated. The electromagnetic response of the graphene nano-disk in the infrared band is analyzed. In addition, considering the common corrugations of graphene materials caused by defects during processing, we study the influence of the geometric parameters of a convex structure in the center of the graphene nano-disk on the resonance intensity, wavelength and field distributions. A spring oscillator model of charge movement is used to explain the simulation results.