In order to achieve electrowetting real-time display, a display driving system, consisting of a DVI video codec system and FPGA timing control system, is designed. DVI video codec system is responsible for obtaining signal sources and for image coding and decoding. FPGA is responsible for buffering and processing of video data and for controlling electrowetting driving waveforms. This paper also proposes an improved multi-grayscales dynamic symmetrical driving waveform, which improves the ink-splitting phenomenon and suppresses the charge-trapping phenomenon while increasing the gray level. The results show that the driving system successfully improves the problems of oil-splitting and charge-trapping, and drives the 1024x768 resolution electrowetting display to play video in real time following the computer. The frame rate of the video reaches 60 frames/second, and the highest gray level of the pixel reaches 15. These properties meet the requirements for dynamic display of the electrowetting paper.

The fluorescence enhancement effect of CdSe quantum dots (QDs) was measured by using a picosecond pulsed laser with a 532 nm excitation wavelength to induce surface plasmon (SP) on a gold nanograting surface. A layered thin film was prepared on the gold film surface of silicon fund by atomic force microscope (AFM) etching and self-assembly method, respectively. The fluorescence spectrum of CdSe QDs was measured by adjusting the power of picosecond pulsed laser on a micro-Raman measuring platform. The results showed that the structure of the gold nanograting and CdSe QDs could greatly enhance the far-field fluorescence of CdSe QDs, the maximum fluorescence intensity was up to 7.80 times, and it had been saturated rapidly at the point of reaching the maximum intensity. The results of this study could be widely used in fields of the optoelectronic devices, biomedical detection.

Compared with magnetic switching by an external magnetic field or by a heat-assisted manner, all-optical switching (AOS) can complete the switching process within 100 ps, which has attracted extensive attention from researchers. Among the magneto-optical materials which can realize AOS, the ferrimagnetic GdFeCo has the ability to realize single-shot AOS and possesses great potential in all-optical magnetic storage. In this paper, a microscopic three-temperature model (M3TM) is utilized to simulate the AOS process of GdFeCo, which is also demonstrated experimentally, under the excitation of a single laser pulse based on the heating effect. By using this M3TM, the AOS dynamics and the final magnetization states of GdFeCo induced by single laser pulses with different energy and pulse widths are calculated and analyzed concretely. Compared with the atomic spin model and the Landau- Lifshitz-Bloch (LLB) model, M3TM provides a more concise time-varying expression of the magnetization of GdFeCo and explicitly addresses the dissipation of angular momentum after the laser-pulse excitation, which enables faster calculations of the heat-induced magnetization dynamics in magneto-optical materials with large areas.

Pressure-sensitive paint technology is a wind tunnel pressure measurement frontier technology with high economical efficiency and high speed. In the wind tunnel test, due to the strong wind, the model will be distorted, making the wind image and the windless image difficult to register, which will seriously affect the pressure measurement accuracy. In response to this problem, this paper innovatively applies the two-dimensional non-rigid iterative closest point (ICP) algorithm to solve this problem. The point cloud method is used to make the image detail area to be effectively registered, and it is also conducive to the subsequent three-dimensional reconstruction work. However, due to the two-dimensional non-rigid ICP algorithm, only the two-dimensional coordinate positional relationship is considered. The correlation of the pixel grayscales of the pressure-sensitive paint image is neglected, so that the registration accuracy is not too high. However, if the three-dimensional non-rigid ICP algorithm is directly used, misregistration will occur. Therefore, in order to further improve the registration accuracy, this paper proposes a non-rigid ICP algorithm based on pixel-based search strategy. The algorithm designs a dual-target search strategy that takes 2D coordinates and pixel gray values into consideration and achieves accurate local matching, realizing point search and double goal optimization. The algorithm of this paper is compared with five registration algorithms on multiple sets of pressure sensitive paint images. The experimental results show that the proposed algorithm has the best registration accuracy. Compared to the suboptimal algorithm, the RMSE is improved by more than 15% and the NMI is increased by about 5%.

The complex background and laser stripe noise affect laser stripe extraction. Adaptive double threshold segmentation method and the improved gray weight model are proposed in this study. First, the characteristics of the laser stripe and the source of noise in the image are investigated. Bilateral filter is applied to remove the noise of images. Subsequently, the gray histogram of laser image and the double threshold are computed. By sub-regional processing, initial stripe center and stripe width of binary images are obtained. Finally, the sub-pixel center of the laser strip is extracted by the proposed model. The double threshold segmentation method and the improved gray weight model are compared with the traditional algorithms. The results show that the double threshold method is more accuracy in extracting the laser stripe region than the extreme value method and the Otsu method. Comparing with the residual value of sub-pixel center, the improved gray weight model (0.23) has better results than the gray-gravity method (0.71), the extreme value method (0.86), and the Gaussian fitting method (0.86). The algorithms proposed in this study avoid the impacts of complex background and laser stripe noise, increase the accuracy of the laser stripe center positioning and extract the stripe center extraction fast and accurately in complex backgrounds.

The modular design and multi-channel integration has become the main thought of developing the photoelectric equipment, and the multi-axis parallelism directly influences the equipment performance. The current methods cannot meet the actual testing needs of multi-spectral, multi-axis, high-precise and large axis space. Thus a multi-spectral and multi-axis parallelism testing scheme is put forward by adopting the designing thought of reflective type and optical axis translation. The reflective collimator is designed to solve the multi-spectral and multi-axis parallelism testing problems, and the optical axis translation design can increase the axis space of multi-axis parallelism test. The results show that the parallelism testing error is less than 0.134 mrad and the axis space can reach 0.5 m, which can satisfy parallelism testing needs of most photoelectric equipment.

For ship angular flexure measurement based on the ring laser gyro units, a simplified attitude matching method has been proposed, where the Kalman filter observation provides direct measurement of the desired ship angular flexure plus the 'relative attitude' term. The 'relative attitude', insensitive to the gyro biases of each LGU, arises from the gyro bias difference and initial ship angular flexure. Additionally, considering its slow-varying characteristics, the angular rate of the quasi-static angular flexure should be modeled as random walks. Numerical simulations validate that the simplified attitude matching method can track both the slow-varying angular flexure caused by sunshine heating and the short-time large-magnitude angular flexure caused by factors such as helm's operation. According to full-scale experiments in several actual ships, the proposed method can reach an accuracy of 20″.

Aiming at the application of natural objects false target in laser decoy jamming, its deceiving ability characterized by decoy airspace was calculated and analyzed. On the premise of full considering the reflection characteristics of target, the intensity of jamming-indicating laser, atmospheric laser attenuation coefficient, and other factors, the analysis model of decoy jamming ability for false target was established under the condition of suppression coefficient K (≥1). Furthermore, the effectual decoy airspace of common natural objects was analyzed under typical condition. The results show that the effective cheating airspace of false target is closely related to the type of targets, and the deceiving ability of vegetation, gravel and diffuse reflection objects is enhanced in turn under the same conditions. There exists a mirror reflection component that is much smaller than the diffuse reflection component in the decoy airspace of vegetation and gravel natural objects, and the variation of the incident angle of jamming laser has obvious influence on the distribution of effectual decoy airspace. However, there is no obvious trend change rule for the decoy airspace of vegetation targets with the incidence angle. The research results are instructive for the reasonable application of typical natural objects used for false target.

Because the double-wedge system can accurately adjust the orientation of the optical axis, it has the advantages of simple and compact structure, fast adjustment speed, and large adjustment angle. In order to meet the needs of a certain product, optical axis adjustment trajectories of concentric circles and zigzags are realized. Based on the existing theories, this paper establishes the corresponding formula by establishing the relationship between the optical axis deflection angle and the bi-wedge rotation angle model, and combines the Matlab simulation, the fitting and the actual product testing, and designs the use of ARM and computer-controlled bi-optical wedges to adjust the orientation of the optical axis. The results show that the error of the optical axis pointing adjustment of the scheme is less than 0.5°, and the expected trajectory can be achieved to meet the requirements of actual products.

A continuously tunable Q-switched all-fiber Er-doped laser based on a 45° tilted fiber grating and tunable bandpass filter is demonstrated. The 45° tilted fiber grating is used to achieve the nonlinear polarization rotation (NPR) along with two polarization controllers (PCs), Q-switching is realized due to the fact that the NPR effect induced intensity-dependent loss. Under the pump power of 655 mW, the Q-switched optical spectrum can be continuously tuned from 1512 nm to 1552 nm by simply rotating the tunable bandpass filter. During the wavelength tuning process, the average output power increases from 0.282 mW to 4.884 mW while the repetition rate enhances from 27.3 kHz to 119 kHz. To the best of our knowledge, this is the widest continuously tunable range of Q-switched fiber Lasers based on nonlinear polarization rotation effect and spectral bandpass filter.