Design of Photoelectric Detection System Used for Atmospheric Microdroplets and Modulation Transfer Function Model of Gaussian Beam

Atmospheric corrosion is an electrochemical corrosion process of metal materials in the atmospheric environment. Microdroplet phenomenon is an experimental phenomenon in the early stage of atmospheric corrosion, which is closely related to atmospheric corrosion. Photoelectric detection of microdroplet phenomenon has become a technical means to study atmospheric corrosion. A set of microdroplet photoelectric detection systems with small size, high integration, and low detection limit is designed and constructed. First, the microdroplet optical chip is designed and fabricated. The microdroplet chip with a single function is replaced by the microdroplet chip with optical microlenses, and the miRNA is detected on the photoelectric platform of the optical chip. The optical fiber is adopted to replace the traditional objective lens to excite the optical path, reduce the volume of the spatial optical path, and realize the miniaturization of the photoelectric detection system. Based on this system, the nonlinear relationship between atmospheric turbulence effect and atmospheric optical parameters is analyzed with Gaussian beams propagating in the atmosphere. In the experiment, the detection range of the photoelectric detection system is 5 nM~100 nM, and the linear correlation is 0.9958. The signals of Cy3 and Cy5 are detected by two groups of photomultiplier tube (PMT) to realize the detection of miRNA. Microlenses enhance the intensity of the photoelectric signal and reduce the detection limit. Microdroplets are used to encapsulate miRNA, reduce the amount of detection material, and solve the degradation of detection material by RNase. The modulation transfer function model of Gaussian beam is established with the assistance of the photoelectric detection system, which is suitable for the case that cannot be ignored in Kolmogorov turbulence under the action of internal/external scale.