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This study investigates white light emitting diodes (LEDs), packaged with an omnidirectional reflector (ODR) and UV LED of 378 nm. The current work designs an ODR to solve the problems of UV leak and low phosphors conversion efficiency with a thin film structure of S/(HLH)n/air modified from a quarter-wave stack. Since an ODR is a perfect dielectric mirror for UV light, the UV leak can be eliminated and recycled to enhance phosphors conversion efficiency. By measuring the emission spectrum of a white LED with an ODR, the orientation distribution of the color properties, and the radiation power, the current study did not detect any UV leak. The average luminous intensity enhancement is 15%.

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An aspherical mirror is made by a thin-film coating technique. A special mask is placed between the evaporation source and the substrate that is to be coated as an aspheric. The design principle of the mask is fully described. An ion-assisted deposition technique is used to relieve aluminum film stress and to increase surface reflectance. The final wave front is tested by conventional interferometric methods for aspherics. Less than one-fifth of a wave (632.8 nm) of spherical aberration is achieved without much trial and error.

In this paper, the changes of oxidation temperature of sulfide corrosion and the deficiency of distributed optical fiber application were analyzed. The test platform of oxidation temperature of sulfide corrosion was established, and the performance test of optical fiber and the simulation of oxidation temperature of sulfide corrosion were realized. The hardware part of the control system used STM32 as the controller, the software part was based on the process characteristics of the controlled object, using MATLAB to carry out the simulation of PID, fuzzy, fuzzy PD plus I, fuzzy PID algorithms, and their performance are evaluated using both single indexes and comprehensive indexes. The experimental results also showed that the proposed fuzzy PID can achieve better control performance with less overshoot and shorter setting time. Therefore, the fuzzy PID was chosen as the temperature control algorithm to build the optical fiber sensor test platform, and an alarm method for testing the oxidation temperature of large area sulfide corrosion based on the optical fiber performance was obtained. Then, considering the influence of spatial resolution on optical fiber sensor, this paper used piecewise PID to simulate the temperature rise process of three stages of sulfurization corrosion and oxidation. The results showed that the alarm method of oxidation temperature of sulfurization corrosion has limitations for small-scale oxidation of sulfurization corrosion, and it needed to be combined with machine learning to identify temperature anomaly.