Terahertz time-domain spectroscopy (THz-TDS) technology is a new developing technology in recent years, which can get electric field intensity and phase information at the same time. Consequently via Fourier transform of the input pulse and the propagated pulse, the optics, electrics and dielectric characteristics of the sample changing with terahertz frequency can be precisely characterized. The methods to generate the terahertz wave by photoconductive antennas, optical rectification and air plasmas are described and how to detect the terahertz wave by photoconductive antennas, electro-optic sampling and air plasmas are introduced. The principle, composition and characteristics of THz-TDS system are also described. Furthermore, the applications of the THz-TDS in various research fields are discussed. Finally, the development of this technology is forecasted.

With the continuous pursuit of optical instrument resolution, the concept of super-resolution is presented. Several kinds of super-resolution technologies in the optical microscopy and projection lithography system are mainly researched and introduced. And the difference and relation of the super-resolution technology between the two super-resolution projection lithography systems are compared. And the optical super-resolution technology is summarized.

In the production process of fiber image inverters, it is easy to produce chicken defect, spot and other defects, and how to automatically identify the defects has been the focus of research. A threshold segmentation method is proposed which smoothes the obtained filter image to get an average brightness image. And the average image is subtracted from the original image to get a difference image. The difference image is binarized by a threshold to realize the automatic segmentation of the defect. In the experiment, the effectiveness of the above algorithm is verified by using the typical image of the chicken and the spot defects, which indicates that the method can meet the requirements of fiber image inverters.

A diode-pumped Q-switched Nd:YAG-KGW Raman laser operating in dual-wavelength modulation is reported. The novel design of segmented circular laser diode (LD) arrays side-pumped structure with conductive and air cooling has great potential to be used in compact and miniature laser systems. The output wavelength of the 1 159 nm and 1 177 nm modulated in spectra-time domains is achieved by an E-O switch, and first-stokes pulse output modulated at spectra-time two-dimensional domains. Pulse energy up to 114 mJ at 1 177 nm and 98 mJ at 1 159 nm are obtained respectively, corresponding to diode-stokes efficiency of 15.3% at 1 177 nm and 13.2% at 1 159 nm.

The output of 2.7 μm wave band laser with high peak power is obtained by KTiOPO4 (KTP) crystal optical parametric oscillation (OPO) pumped by 1 064 nm laser. Experimental results are analyzed in detail. The pump source is an electro-optical Q switched Nd:YAG laser, and the OPO is singly resonated. Two identical KTP crystals are placed with opposite optical axis to compensate the walk off effect. The crystals are cut as ?=0°, θ=62° to generate 2.7 μm wave band laser. To utilize the larger effective nonlinear coefficient, the phase matching is based on type Ⅱ(B) (o→o+e). When the pump energy of the 1 064 nm laser is 89 mJ with a pulse width of 10 ns, an output energy of 7.5 mJ with a pulse width of 8.5 ns at 2.67 μm is obtained.

The linear responsivity comparison experiment of charge-coupled device (CCD) to 808 nm high and low repetition frequency laser with 100 fs pulse width and 808 nm continuous wave (CW) laser is studied. Experimental results show that the power responsivity ratio of CCD to the laser with 100 fs pulse width and CW laser is close to 1 when CCD is in linear responsivity range, which means the responsivity is no difference. From CCD principle, the response output is in proportion to the laser power received in integrated time, which indicates that the CCD power responsivity has nothing to do with width of pulse and repetition frequency of laser.

Three 532 nm pulsed lasers with different pulse width 30 ps, 100 ns and 4 ns and the same repetition frequency of 1 kHz are used to radiate CCD. The whole phenomena from linear responding, image element saturation, saturation cross talk and damage are observed. The thresholds of saturation and damage are obtained. Experimental results show that the jamming effect induced by picosecond pulse sequence laser is better than that of ordinary picosecond pulse laser, and the power density of picosecond pulse sequence laser is lower than that of picosecond pulse laser for 1~2 orders of magnitude while the same jamming effect is obtained.

According to the basic principle of liquid crystal phased array beam steering mode, the influence on the steering precision of the liquid crystal phased array is analyzed. Precision on steering angle of liquid crystal optical array has been theoretically analyzed on the relative three main reasons. Meanwhile, experimental research has also been finished to obtain encouraging result indicates that precision is better than 2 μrad.

The laser direction finding technology uses the photoelectric detector to receive the laser signal, and calculates the angular deviation according to the deviation from the detector photosensitive surface to the spot center of the target, and then obtains the azimuth information of the target. Laser direction finding technology is widely used because of its large range of direction finding, flexible design of circuit and high precision of direction finding. The photoelectric detection device is the core device of laser direction finding technology, three main detection devices are introduced, the working principle and characteristics are discussed. The quadrant detector (QD) has more advantages through comparison, which is an ideal precision direction finding device, and is more suitable for tracking and measuring of high precision dynamic targets.

Theory thesis is proposed to target detection by using laser echo signals. The principle of spectrum, polarization, position, motion and vibration characteristics extraction of laser echo is discussed. And the method of target recognition using echo signal intensity, pulse width, echo signal tracking, template matching, feature vector extraction and fuzzy clustering is analyzed and summarized.

The simulation and evaluation of infrared imaging systems affected by the laser jamming has become an important issue in electro-optic countermeasure. The laser jamming effect to the target recognition of the infrared images is researched. The infrared images are researched and analyzed to implement synthesized simulation of special targets and scenes. The research object is infrared images. Through the processes of fusion simulation of target and scene, background suppression and target extraction, the performance changes of target detection are researched when the relative distance between the target and the laser spot is different. And experimental results and result analysis are provided.

A 1 908 nm Tm:YLF slab laser pumped by two fiber coupled diode lasers at room temperature is reported. The suitable size of spot is chosen. The maximum continuous output power is 60.1 W at 18 ℃, corresponding to the slope efficiency of 39.8%. The precise control of wavelength is achieved by adopting the method of volume body grating (VBG) with 0.3 mm F-P, corresponding to the full-width at half-maximum (FWHM) of 0.14 nm.

The jamming result assessment factors of multispectral imaging reconnaissance equipments are analyzed. According to the correlation of spectral character curvilinear composed by the different channels of multispectral imaging reconnaissance equipments on the gray value of the same pixel, the identify probability to the target is calculated. Based on the identification probability ratio of multichannel spectral imaging equipments to the target before and after jamming, a jamming effectiveness evaluation criterion on multispectral imaging reconnaissance equipments is presented, which can be used to evaluate the jamming effect.

The research on atmosphere ionized by laser is significant in many areas. The ionization is a multi-process which contains multi-photon ionization and cascade ionization processes. Experimental results show that when the drive voltage of the Nimma-600 laser is 880 V, the area of the plasma reaches to the biggest area after the laser pulse generated about 20 ns, and the last time of the plasma is about 16 μs.

The nonlinear characteristics of Duffing circuit are researched. An experimental circuit capable of generating nonlinear phenomena is introduced. According to the Kirchhoff circuit principle, the general expression formula of Duffing circuit equation is obtained. Furthermore, MATLAB program is used to simulate the Duffing circuit equation. Simulation results show that the Duffing circuit system can present dynamical behaviors, and the simulation results are in accordance with the experimental results.

A new analysis method of structural reliability based on universal generating function (μ function) is produced, its basic thinking is based on the z transform of discrete signal processing, it transforms random variable into μ function model which describes its uncertainty. And it utilizes favorable properties and logical relation algorithm of μ function to pass the input uncertainty to the output uncertainty. According to the reliability indexes of μ of μ function model is established in order to solve the computing problem of functional algebraic operation of μ function. Compared to Monte-Carol method, the idea based on z transform transforms the problems of discrete real domain into the problems of discrete complex domain, and conducts reliability analysis in domain which is similar to discrete complex domain. The calculating examples verify high efficiency and feasibility of the proposed method.

Micro-machined quartz tuning fork gyroscope as the speed feedback system in vehicle steering system, its output noise and random drift directly affect the final stable precision. In response to this problem, an adaptive forward predictive filtering method is proposed to eliminate gyro noise, and an incremental or decreasing variable is introduced into the velocity closed loop system according to the error of the angle value of the grating and the initial stable angle. The actual tests verify that the method can improve the stable precision to±7.2″, which verifies the effectiveness of the method.