Phase‑sensitive optical time domain reflectometry （φ‑OTDR） combined with existing communication optical fibers in optical fiber composite overhead ground wires （OPGW） captures fiber vibrations caused by wind‑induced movement along overhead transmission lines. However， the mapping law between vibration signals and actual wind speeds is difficult to establish and traditionally relies on manual judgment.To address this issue， the random forest algorithm was introduced into the data analysis for distributed optical fiber wind speed monitoring. A three‑month field test was conducted on a 220 kV line with a total length of approximately 44.16 kilometers， and the experimental results showed that the proposed solution could predict wind speed in real‑time and evaluate its impact on overhead transmission lines in a distributed manner. This method could assist in evaluating potential risks brought by wind loads and guide subsequent operation， maintenance， and upgrade to ensure the safe and reliable operation of overhead transmission lines.

A near-eye display （NED） test equipment based on binocular CMOS camera was developed， and a technique for measuring the primary optical properties was presented. Fast and low-cost measurement of NED device optical properties was accomplished via derivation modeling， system design， and calibration tests in accordance with important NED optics principles. The final experiment demonstrated that this test system could save around 60% of the measurement time compared to the previous technique， with a key parameter test error of less than 5%.

Electromagnetic metamaterials are artificial structures composed of periodically or aperiodically arranged sub-wavelength units. They have extraordinary media parameters that do not exist in traditional materials or are difficult to achieve with traditional technology， and can control electromagnetic waves in sub-wavelength scale. Metamaterials are closely related with materials， structures， and functions and hence go far beyond the concept and scope of traditional materials. They have been investigated throughout the fields related to “waves”， including electromagnetic， acoustics， mechanics， heat， quantum， etc. In the past two decades， electromagnetic metamaterials have been an international frontier research hotspot in the field of physics and information， and the related technologies derived from them have also produced a series of applications with significant effects in many fields， such as wireless communication， radar， imaging and so on.

In this study， a systematic study was carried out on the influence of epitaxial growth and chip preparation process on the reliability and accelerated lifetime prediction of AlGaN-based deep ultraviolet LEDs. The impact of Al component in Quantum Barrier （QB）， Al component in Electron Barrier Layer （EBL）， and different table areas of the same size chip on the reliability of deep ultraviolet LED were explored. The Al fraction was determined to be 74% for the QB structure and 75% for the EBL structure with a table area of P68. Thermal and electrical stress aging tests were designed for the optimised deep-ultraviolet LEDs， and the lifetime of the deep-ultraviolet LEDs was predicted by combining the Arrhenius model， the inverse power-law model， and the exponential least-squares fitting. The experimental results showed that with the increase of electrical and thermal stress， the reliability of deep-ultraviolet LEDs decreased， the Arrhenius model predicted the lifetime of 5 027 hours， the inverse power law model predicted the lifetime of 5 400 hours， and the actual lifetime of the deep-ultraviolet LEDs under the normal operating current of 40 mA was 5 582 hours， and the predictive accuracy of the inverse power law model was improved by 6.7% over the Arrhenius model. By shedding light on these crucial factors influencing the reliability of deep ultraviolet LEDs， the study laid a robust theoretical groundwork. This groundwork would not only facilitate further exploration into reliability enhancement，but also pave the way for widespread application and adoption of deep ultraviolet LEDs in various industries.

A calibration scheme was proposed that made appropriate adjustments based on the general steps of lithography exposure and achieved accurate lithography exposure using incompletely matched masks. This study provided a new approach to improving chip preparation efficiency and ensuring alignment accuracy.

An ionic liquid additive 1‑propyl‑3‑methylimidazole chloride （MPICl） was introduced into the perovskite active layers and used to prepare highly efficient and stable inverted perovskite solar cells （PSCs）. The experimental results showed that the coordination bond formed by Pb2+ and lone pair electrons on N atom of MPICl imidazole ring could contribute to cooperative defect passivation and significantly inhibit non‑radioactive charge recombination. As a result， the power conversion efficiency （PCE） of the PSCs was increased from 16.69% to 18.18%， and the MPICl‑perovskite devices achieved significantly long‑term stability. This study provided an easy strategy of further reducing defects to obtain high‑performance devices.

4‑T tandem solar cells was constituted of a semi‑transparent organic solar cells and the Cu2ZnSn（S，Se）4 solar cells. The anti‑reflection of the pyramidal micron polydimethylsiloxane （PS‑PDMS） was applied to trap the sunlight. The impact of size and position of PS‑PDMS on the performance of 4‑T tandem solar cells were analyzed. The width size of the micro‑pyramidal structure was various of 9~18 μm， and the results showed that 9 μm width of PS‑PDMS films could achieve the most significant anti‑reflection effect when it was pasted on the bottom cell of 4‑T tandem solar cells. 11.26% PCE of the 4‑T tandem solar cells was obtained. Compared with that of the single Cu2ZnSn（S，Se）4 solar cells， the optimal PCE of 4‑T tandem solar cells increased by 27.51%.

In order to ensure the stability of the operating temperature of a butterfly shaped semiconductor laser， a temperature control system based on improved particle swarm optimization （PSO） was proposed. The internal TEC （Thermo Electric Cooler） of the butterfly shaped semiconductor laser was used as the controlled object to calculate its transfer function. A temperature control system simulation model was built in Simulink simulation tool to analyze the impact of temperature on the laser operation. Based on the improved PSO algorithm to optimize PID （Proportional Integrated Derivative） controller parameters to achieve good temperature control effect， the experimental results showed that optimizing PID controller parameters through the improved PSO algorithm could ensure the safe and stable operation of the laser in the temperature control circuit， and achieve the goal of high stability and fast response speed of the laser TEC temperature control system. The maximum temperature fluctuation error within two hours was 0.13 ℃， and temperature stability increased to 0.52%.

To solve the problem that the receiving equipment was generally expensive and the integration was not high enough， a four‑channel ADS‑B receiver based on low cost and high integration was designed.This device was the first four‑channel small RF receiving device in the industry that integrated low‑cost real‑time signal acquisition， on‑board multi‑band ADS‑B real‑time decoding and other functions.The equipment was based on ZYNQ‑7000 series chip as the main control chip. The design included RF front‑end receiving circuit module， signal acquisition circuit module， high‑speed and large‑capacity data storage module， etc.， which realized high‑speed sampling and processing of target signals， such as ADS‑B.The test results showed that the receiver could successfully receive and demodulate ADS‑B long message signals， providing a set of low cost and low power overall solution for high performance data acquisition and real‑time signal processing.

Based on Computational fluid dynamics （CFD）， the methane telemetry path under the condition of non-cooperative targets was analyzed. Combined with the one-dimensional line of sight integrated concentration characterization model， a numerical simulation study of methane emission under different wind speeds and different leakage locations was carried out to explore the change law of methane integrate concentration value under different scanning schemes， to obtain the optimal scheme for laser detection of oil and gas stations， and match the optical path with the actual detection path. The research results indicated that a scanning scheme with a horizontal distance of 5 m in the optical path could achieve rapid scanning and alarm of leaked gas in oil and gas field stations under different leakage locations and wind speed conditions. As the horizontal distance between the leak location and the detector increased， the wind speed increased. The scanning scheme with a horizontal distance of 5 m in the optical path had more obvious advantages in alarm time compared to other schemes.

The combination of Variational mode decomposition （VMD） and Savitzky-Golay filtering （SG filtering）， abbreviated as VMD-SG filtering， was suggested for the reduction of noise in signals containing noise， with a particular emphasis on the absorption spectroscopy of tunable semiconductor lasers and the issue of noise in the second harmonic during the measurement of low concentration gases. The optimal selection of VMD balance parameters was analyzed， and the set frame length adjustment factor P was utilized to select the optimal frame length for SG filtering. When compared with other denoising algorithms， it was found that the VMD-SG filtering denoising algorithm performed better in terms of signal-to-noise ratio， root mean square error， waveform recovery， and the error of the second harmonic feature point. At signal-to-noise ratio （SNR） of -7.838 9 dB， an improvement of 22.047 dB in SNR was achieved by the algorithm， a root mean square error of 0.015 4 was recorded， and a correlation coefficient of 0.985 with the standard second harmonic was determined. The results were indicative of the fact that the tunable diode absorption spectrum composite denoising technology， which was based on the VMD-S-G filtering denoising algorithm， could more effectively enhance the quality of signals in weak signal conditions. It was also found to be beneficial for enhancing the accuracy of gas inversion and the sensitivity of system detection.

Aiming at the requirements of lightweight and low power consumption of airborne equipment， a reinforcement method of airborne LCD module based on support frame was proposed. Finite element iterative simulation calculation was used to optimize the design of heat dissipation plate reinforcement ribs and reduce the structural weight； Based on the ultra-thin light guide plate with a thickness of 2 mm， the design of the current backlight plate was improved through LED selection and LED layout， which improved the optical coupling efficiency of the ultra-thin light guide plate. Through calculation and test verification， the backlight power consumption of the LCD module has been significantly reduced.

The difficulties and challenges of the UDC technology were analyzed， the progress of each key technical point were presented，and potential solutions were explored. The transmittance of UDC area could be improved to 20% by “Driving Circuit Edge-placed”， reducing the pixel anode size， etc.， and it could basically meet the needs of the front camera on the mobile phones. “One sub-pixel driving circuit drives the same color sub-pixels” could reduce the number of lines while keeping the number of OLED pixels unchanged. Destroying the pattern regularity of the UDC area could suppress the diffraction to improve the selfie performance of the front camera. Optimized pixel layout could reduce the obviousness of the separatrix between the low PPI and high PPI area. The brightness and color differences between the UDC area and the main screen could be eliminated by optimizing Gammas of two screen areas and Demura algorithms.

In order to improve the color deviation of the SUVA3，by which the left and right visual role bias （CR（80/20）） was worse than that of UV²A process，the combined energy exposure （PBS + WGP mode） ， ITO Slit angle and WGP angle were studied from the process，design and other aspects. The experimental results showed that the ITO slit +WGP mode had better effect，as far as the color deviation &mass production were concerned，and the color deviation of SUVA3 could be optimized to the level of UV2A.