A finite difference method based on Helmholtz equation is presented for the mode calculation of active unstable resonator. The finite difference method for the optical field transmission is analyzed theoretically, and the numerical calculation model for active unstable resonator is established. The optical field distribution of laser resonator output can be obtained accurately and quickly based on the calculation model. The numerical sim. ulation results for bare cavity mode and active cavity mode with non-uniform gain are presented respectively. The simulation results for bare cavity mode are also compared with the modes calculated by fast Fourier transform, and it shows that the numerical simulation methods and the calculated modes are reliable, time-saving, and can be used for model calculation with large Fresnel number.

For the problem that laser pulse correlation detector faces challenges of both imperfect narrow-band filter and dependency of background light interference received by parallel detectors, an improved method is proposed. Two of four parallel detectors are used for receiving target signal and background light, while the other two receive background light only. The correlation background light interference is restrained through subtracting background light from the mixed signal before correlation processing. Simulation results demonstrate that the light out of working spectrum is remarkably resisted, and false-alarm probability caused by background light interference is lower effectively, which prove the method is feasible and effective.

A method for developing the virtual reality simulation system based on a Visual C++ and Multigen Vega is introduced. First, the 3D model with the texture is built by Greator software, and then the infrared texture and atmosphere conditions are modeled respectively by TMM and MOSART, finally IR image is simulated by Vega sensor model. The full design functions of IR visible simulation system are realized by using Vega API based on Visual C++ integrated development environment. The simulation procedures and simulation results are given, the simulation results prove that this method gets the ideal effects of simulation.

Based on the distribution characteristic of the vapor and CO2 in the atmosphere, and the traditional calculation method of atmospheric absorption transmittance, the calculation method of atmospheric infrared absorption transmittance is analyzed. The calculation model, calculation steps are provided. Moreover, taking the CO2 as anexample, the CO2 atmospheric absorption transmittance in 2.7 μm is calculated. By simulating, the relations between atmospheric absorption transmittance and target height are obtained.

The common area of the candidate images is obtained by using the regional split and merge algorithm, meanwhile two candidate images are processed by the multi-scale decomposition. the weighted average and coefficient selection are done for the low frequency coefficients of decomposition and high frequency coefficients according to the fusion measuring indexes and the regional similarity, the fusion image is obtained by inverse wavelet transform. The results show that region-based fusion algorithm can preserve more details.

The principle which can cause the defocus of the image surface is discussed. The domestic and foreign athermalisation methods are introduced, the advantages of passive athermal compensation of the optical system are analyzed, athermal equations of thermal compensation are derived. An athermal compensation method which combines the optics with the machinery is proposed. Using this method, the optical lens and the transfer function can keep relative stability, when the environment temperature changes, that is, the athermalization of optical system is basically realized, it is significant for athermal design of infrared optical system.

The study on the spatial optical solitons with orbital angular momentum is introduced, which includes two contents: the elliptic beams with orbital angular momentum can propagate in the isotropic medium as a soliton; the rotating spatial solitons are studied in the transporting medium, optical mode and the rotating method.

The main factors which influence the compound between the passivation medium layer and the crystalline silicon are analyzed, including the interface state density(Dit), surface charge density of medium lay. er, doping type and doping concentration of the substrate. When the carrier injection level varies, the passivation quality is closely related to the charge type in medium layer and silicon doping type. As the carrier injection level decreases, the passivation quality of the passivation medium with positive charge on the P-type(N-type)sili. con decreases, but the passivation quality of the passivation medium with negtive charge on the P-type(N-type)silicon still remains constant. The reason of the passivation quality varying with carriers injection level is analyzed. The guiding suggestion for the high effiency crystalline silicon cells is proposed, it is very important for silicon cells operating at low level injection level(5×1014 cm-3).

The effect of the reflection bowl and lens on the luminous intensity distribution is analyzed by the orthogonal experiment method, and the high intensity, narrow beam and high-power LED with the optimized parameters is simulated. The design possesses guiding significance for LED optical system, and can help to improve the efficiency of the optical system and reduce the experiment cost of LED package.

The background and significance of the research on optical generation technology of millimeter-wave are introduced. Several mainstream optical generation technologies of millimeter-wave are reviewed, including direct-modulation, external-modulation and optical heterodyne; the improved methods are also summarized, including a novel scheme for optical millimeter-wave generation based on double-sideband modulation, and a new double-uniform fiber grating millimeter-wave generator and so on. In addition, two novel optical generation technologies of millimeter-wave are reviewed, including a method to realize millimeter-wave subcarrier optical signal generation by using a double wavelength optical spectrum of a certain distance with fiber grating filter and optical frequency multiplication.

The digital image/speckle correlation method (DSCM) is a useful nondestructive testing method in the whole displacements and strains. Designing accurate sub-pixel searching algorithms is an important problem in order to enhance the accuracy of measurement. The principle of the digital image/speckle correlation technique is studied, and a kind of gradient method with changeable step is proposed and applied to the correlation searching. The reliability and stability of this algorithm is proved by the displacement analysis of the computer-simulated speckle images, and the translation of the rigid is measured, the results indicate that this algorithm is a stable and reliable, effective searching algorithm, and it can be used in the measurement of displacement fields.

A classification method of decision tree for multi-spectral images，which combines the spectral features with the texture features is presented. The Landsat-7 images are taken as the experiment data，the integrated thresholds of the various ground objects are determined by analyzing characteristic values of the Landsat-7 images spectrum，NDVI，NDWI and NDBI. Meanwhile，the texture information of images including the contrast，entropy，homogeneity and correlation are acquired by means of using Gray Level Co-occurrence Matrices. On this basis the Landsat-7 images are classified by the decision tree classification method. The results indicate that the accuracy of decision tree classification based on spectral and texture features is higher than that of the maximum likelihood and traditional decision tree method.

The micro-scale and low cost micromachining gyro is widely used in the attitude stabilization and control system of Microsystems. The signal processing technology for the non-driven silicon micromachining gyro is studied. The signal for 3D attitude angular velocity of the roll, pitch and yaw of the rotating carrier is extracted and output by hardware circuits, software algorithm and compensation technique. The gyro is used in the attitude measurement and control technology fields of the rotating carrier.

The speech signal processing is the cross-discipline which combines the voice science with the digital signal processing technology. The voice is taken as a special signal, i.e. a complex vector. By using the command functions in the digital signal processing tool－MATLAB, the digital signal processing can solve many problems. The spectrum of voice signals are analyzed, which is the same as the spectrum analysis of common signals. A variety of digital filters (FIR low-pass filters, high pass filters, band-pass filter and IIR band stop filter) are used to filter and analyze the voice, and the voice signals are compared with the original signal. Finally, the conclusion is drawn.

The electromagnetic compatibility（EMC）and the control strategies of EMC are introduced. The principle，occasion and method of the prediction analysis for EMC are introduced，then the technologies of EMC，including grounding，lap joining，arrangement，wiring，shielding，filter，lightning protection are analyzed. The effective engineering design is proposed from the professional point of view，and is described based on the applications. The basic principles of equipment and cable arrangements are introduced. The advices on how to improve the EMC level for designers are proposed.

In windows 2000 environment, the method of serial port communication development is summarized. Every method to program is introduced, and their advantages and disadvantages are compared. For application requirements, the appropriate development methods are selected. The serial port data processing and serial port module packaging are studied. The method of ring buffer data processing and the method that the serial port communication module is packaged using dynamic-link library (DLL) are introduced, and these methods are validated by the code of Visual C++.

In order to realize the data acquisition, processing, communication and test of underground multi-channel gas concentration, the optical fiber SPR sensor network based on the single-chip device is designed. Aiming at the single-chip device, this network combines optical switching devices with serial devices. In order to achieve multi-channel communications, and taking the mechanical optical switch with low loss and high scalability into account, so 32 groups mechanical optical switches are used; 89C52 single-chip controls the optical switch to realize 32 groups cycle test. This single-chip has high-capacity and high-speed characteristics; In addition, the total program of system operation is written, the gas concentration alarm is simulated by LABVIEW.

The launching height is an important technical parameter for the signal flare. In order to test the launching height of the signal flare, the measurement technology based on the single area array CMOS camera is proposed by establishing mathematical model. By calibrating the camera angle of view, the video images collected from CMOS camera are processed by MATLAB, and the real-time measurement for launching height of signal flare is achieved. Meanwhile, the sources of error are analyzed and the accuracy of the system error is estimated, and the launching height of the signal flare is between 159.348 m and 167.567 m. The result shows that the advantages of the measurement system are low cost, simple operation, easy deployment, high precision, high degree of automation, without limitations of measurement environment and errors of manual reading, etc.

To deal with the heavy-tailed issue of the video object with abrupt turns，a particle filter tracking algorithm based on switching observation models is proposed. According to the presented switching rule，to improve the tracking precision，the observation likelihood of Gaussian distribution is used when the object moves steadily，and the observation likelihood of multivariate Laplace distribution is adopted to surmount the heavy-tailed issue when the object turns abruptly. The simulation result shows the algorithm is robust and effective at abrupt turning object tracking.

According to the requirements of the trajectory measurement in the load test for aircraft landing gear，a safe and reliable trajectory test and the monitor scheme are designed by using electro-optic theodolite (EOMS)，GPS (global position system) and total station positioning system（TPS110）etc. The methods of the aircraft trajectory，camera calibration and precision detection based on the image sequence are proposed，from the view of the photogrammetry and projective geometry. The analysis proves that the method of the measurement precision is better than 6 cm. The designed system has been used in flight test and has got a good application.

As an important part of the electro-optic technology, the PSD (position sensitive detector) technology is widely applied in various subject fields. The precision damand for PSD system signal is becoming more and more strict. It requests a better method to reduce the noise of PSD system signal. In view of the PSD system signal characteristic, the db8, sym8, coif8 are choosed to process and compare with the signal which contains chirp. And the simulation is done by the wavelet GUI in the MATLAB software. In order to obtain the most suitable wavelet processing method, the simulation resuls are compared. The simulation results indicate that the algorithm can provide a better way for filtering and de-noising.