为解决海上单目图像测距难的问题, 提高对海上图像的信息挖掘程度, 提出一种单目测距方法。在海天线检测和位姿解算单目测距技术的基础上, 通过图像中的海天线对相机位姿进行标定, 获取相机外参;再结合提前标定的相机内参, 构建目标与相机在成像空间中的几何关系模型;考虑地球曲率影响, 推导出了基于海天线标定的海上实时单目测距方法;最后利用蒙特卡罗法对测距模型进行仿真, 分析了其误差特性。

多芯片LED光源的可靠性分析涉及到光、电、热多个物理场, 高精度的多场分析结果会导致计算资源过多、计算时间过长、计算难度大等问题。为解决上述问题, 本文分别利用传统的有限元算法(FEM)和高效的人工神经网络方法(ANN)进行LED光源温度分析, 并讨论两种方法的优劣性。最后, 通过将FEM分析单一传热物理场的优势与ANN计算时间短、计算资源需求低的优势相结合, 归纳出一种更为高效的方法来进行多芯片LED光源的散热分析。利用该方法, ANN的预测数据与训练数据之间的相关系数达到了0.997 79, 预测结果与实际热分布图有良好的匹配, 计算资源相比传统的FEM方法节约了59％。该方法的应用能够在满足精度的前提下耗费更少的计算资源和时间, 同时提高了分析的灵活性。除此之外, 该方法对求解大功率LED光源寿命等可靠性问题也具有一定的参考价值。

We propose employing multi-beam propagating technology to mitigate the influence of atmospheric scintillation to the wireless optical code division multiple access (WOCDMA) system and then deduce the bit error rate (BER) formulas of systems in weak and strong scintillations, respectively. According to simulation experiment results, multi-beam propagation can improve the system performance very well compared with single-beam propagating technique. Moreover, the more beams we use, the better the performance we get. When the received optical power is –30 dBm, the BER of the system employing four beams is 5 and 1 dB lower than that of using single-beam propagating technique in weak and strong scintillations, respectively.

A Yb:YAG disk laser with V-shaped stable resonator and active-mirror configuration, end-pumped by a 940-nm InGaAs laser diode array, is demonstrated. Performances and optimization of the disk laser at low temperature over a range of 130–200 K are investigated theoretically and experimentally. Laser output energy of 1.46 J/pulse operating at 10-Hz repetition rate is obtained with the optimum output coupler transmission of 30%, and the corresponding optical-to-optical efficiency is 48.7%.

The accumulation effects in high-reflectivity (HR) HfO2/SiO2 coatings under laser irradiation are investigated. The HR HfO2/SiO2 coatings are prepared by electron beam evaporation at 1 064 nm. The laser-induced damage threshold (LIDT) are measured at 1 064 nm and at a pulse duration of 12 ns, in 1-on-1 and S-on-1 modes. Multi-shot LIDT is lower than single-shot LIDT. The laser-induced and native defects play an important role in the multi-shot mode. A correlative theory model based on critical conduction band electron density is constructed to elucidate the experimental phenomena.

Antimony-based bismuth-doped thin film, a new kind of super-resolution mask layer, is prepared by magnetron sputtering. The structures and optical constants of the thin films before and after annealing are examined in detail. The as-deposited film is mainly in an amorphous state. After annealing at 170–370 oC, it is converted to the rhombohedral-type of structure. The extent of crystallization increased with the annealing temperature. When the thin film is annealed, its refractive index decreased in the most visible region, whereas the extinction coefficient and reflectivity are markedly increased. The results indicate that the optical parameters of the film strongly depend on its microstructure and the bonding of the atoms.

A multimode fiber-optic surface plasmon resonance (SPR) sensor with a MgF2 film as a modulated layer is studied. The fiber-optic SPR sensor is investigated theoretically, specifically the influence of the dielectric protecting layer, using a four-layer model. The sensor is then fabricated with the optimal parameters suggested by the theoretical simulation. The sensor has a high sensitivity in the analyte refractive index (RI) range of 1.33-1.40. The best sensitivity of 4 464 nm/RIU is achieved in the experiment. The use of dielectric film (MgF2) can not only modulate the resonance wavelength of the sensor, but also protect the silver film from oxidation.

Intrinsic zinc oxide films, normally deposited by radio frequency (RF) sputtering, are fabricated by direct current (DC) sputtering. The oxygen-deficient targets are prepared via a newly developed double crucible method. The 800-nm-thick film obtaines significantly higher carrier mobility compareing with that of the 800-nm-thick ZnO film. This is achieved by the widely used RF sputtering, which favors the prevention of carrier recombination at the interfaces and reduction of the series resistance of solar cells. The optimal ZnO film is used in a Cu (ln, Ga) Se2 (CIGS) solar cell with a high efficiency of 11.57%. This letter demonstrates that the insulating ZnO films can be deposited by DC sputtering from oxygen-deficient ZnO targets to lower the cost of thin film solar cells.

A new process of magnetorheological figuring (MRF) based on the deliquescence theory is proposed to finish KDP crystals. A novel, non-aqueous, and abrasive-free magnetorheological (MR) fluid is explored, and polishing experiments are performed on a self-developed MRF machine. The removal mechanism is reckoned to be the result of a combination of dominant chemical etching and accessorial mechanical drag. The results indicate that the surface roughness of I plate KDP of 80×80 (mm) polished by MRF is 1.2 nm (root mean square (RMS)), and the tool marks are completely removed. The surface accuracy by MRF is 0.035\lambda (RMS), and the low/middle-frequency errors are significantly corrected after MRF.

We report on a radially polarized and passively Q-switched Nd:YAG/Cr4+:YAG laser. The bulk Nd:YAG crystal is bonded with two undoped YAG crystal end caps to weaken the thermal lens e ect and thus, enhance the extraction of stored energy in the bulk gain material. In the absence of active water cooling, the average laser power reaches 383 mW with 33% slope e±ciency, and the laser pulse achieves 1.457-W peak power, 18.9-ns duration, and 13.9-kHz repetition rate with 97.6% polarization purity.