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ISSN1001-3806 CN51-1125/TN Map

1996 Vol. 20, No. 4

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Study on laser protective eyeglasses performance indexes
Gao Guanghuang, Zhang Guisu, Chen Zongli, Shi Liangshun, Liu Haifeng, Zhou Tieqiu
1996, 20(4): 193-197.
Abstract:
The purpose of this paper is to analysis the laser protective eyeglasses performance and the factors effecting the laser protective performance,such as the laser wavelength,the laser emitting way,the irradiance or exposure,selection of the glass materials,the structure types and the application environment.According to this analysis,the 28 items of the technical specification of laser eyeglass,including the general requirements,optical characteristics,structure parameters and using environment,are determined.
Application of high frequency preionization in high pressure pulse discharge
Wang Youqing, An Chengwu, Zhou Jianguang, Li Zaiguang
1996, 20(4): 198-201.
Abstract:
This paper introduces the theoretical and experimental study of high frequency preionization characters in high pressure discharge.Results show that the high frequency discharge can increase the input power density,if the initial electron density is over 1011/cm3,the requirement of the uniformity of the main discharge pulse can satisfied.
Intensity asymmetry of facet output mode spectrum of a semiconductor laser biased below threshold
Wu Zhengmao, Xia Guangqiong, Chen Jianguo
1996, 20(4): 202-205.
Abstract:
Starting from the multimode rate equations and concerning the fact of wavelength diffe rence of the spontaneous emission peak and gain peak,the intensity asymmetry of the longitudinal mode spectrum of the semiconductor laser biased below threshold is studied.The results indicate that the reason of the asymmetry is from the shorter peak wavelength of the spontaneous radiation than the gain peak wavelength.The experiment confirmed the theoretical prediction.
Ti:sapphire laser performances and the dependence upon the part parameters
Wu Chengjiu
1996, 20(4): 206-209.
Abstract:
According to the optimum design theory of a longitudinally pumped laser,the optimum slope efficiency of a laser of Ti:sapphire with different FOM value,the maximum output power of a laser of Ti:sapphire with different Q value for different pumping power,the threshold,the optimum part length and transmittance of the output mirror have been calculated.The possibility of improving laser performances are discussed as well.
A pre-processing method of interference fringe pattern of transient flow field
Lin Zhenhua, Lu Jian, Ni Xiaowu
1996, 20(4): 210-214.
Abstract:
With a CCD camera,the time sequence pictures of a transient flow field can be taken up.In order to analysis of the dynamic parameters of the field,it is necessary to make the pre processing of the pictures.This paper introduces a pre processing method including the portioning sharpening,vicinity average filtering,bit mapping,Hilditch linking.Especially,a branch eliminating is used for obtaining the continuous interference lines pattern.This method is well satisfied with the requirement of automatical data processing.
Study on discharge parameters of a high repetition rate TEA CO2 laser
Li Lingzhi, Liu Fengmei, Zhao Jingshan, Wang Yusan, Hu Xiaoyong
1996, 20(4): 215-218.
Abstract:
The voltage doubled circuit of a high repetition rate TEA CO2 laser and its discharge processes are described theoretically.The calculated results of discharge voltage,discharge current,discharge resistance and the value of E/N are yielded out.The theoretical results are coincident with the experimental ones.
Determination of location of optical spectrum plan
Ye Liu, Ye Shujun
1996, 20(4): 218-220.
Abstract:
According Fourier optical theory and speckle motion characters,the problem to found the location of a spectrum plan in a optical system has been investigated.The experiment results proved the theoretical analysis is correct.The method can be used in optical information processing system.
Study of tunable infrared light beat generator by laser frequency splitting method
Han Yanmei, Zhang Shulian, Li Kelan
1996, 20(4): 221-224.
Abstract:
In this paper,the experimental study on 1150nm tunable infrared light beat generator by He Ne laser longitudinal mode splitting is reported.The results show that the range of beat frequency of the generator is from 40MHz to hundreds of megahertz.Meanwhile some other characters,for example the mode competition,are studied.
Theoretical and experimental investigation of characteristics of pulsed Ti:sapphire laser
Zhao Changming, Chen AnYao, Jianquan
1996, 20(4): 224-229.
Abstract:
According laser rate equations,the dynamic characteristics of pulsed Ti:sapphire laser has been comprehensively studied.The theoretical study and experimental results prove,if duration of pumping pulse is much less the life of up energy level,(1)the width and waveform of the output pulse is independent of the pumping pulse,(2)the only factor of determining the output pulsewidth is the ratio of pumping energy to threshold pumping energy,(3)the time delay of output pulse is dependent of the pumping pulsewidth and the ratio of pumping energy to threshold pumping energy.
Low energy laser threat and protection in battlefield
Hu Jianghua, Zhou Jianxun, Wang Qingbao, Zhang Baoming
1996, 20(4): 230-233.
Abstract:
This paper introduces the seriousness of low energy laser in battlefield and described laser protection technique and the development intention.
Laser transformation characteristic research of optical windows in optical electrical apparatus
Wang Xuekai
1996, 20(4): 233-235.
Abstract:
In this paper,it is suggested that the optical window of the optical electrical apparatus is scanned with a laser beam to found the laser transformation characteristics of the window for recognition of the optical electrical apparatus.It is the fact that the each optical electrical apparatus has some inhe rent laser transformation features.Based on the fact,a data base of the transformation features of the optical electrical apparatus can be established.It will play a important role in these fields of the optical electrical countermeasure,laser active recognition and laser radar.
Error analysis of dielectric optical multilayer variation of sensitivity factor with layer thickness
Fan Zhigang, Zhang Wei, Li Yigui, Lu Chunhua
1996, 20(4): 236-240.
Abstract:
The formulas of sensitivity factor varied with the thickness of specific layer of a multila yer is derived in this paper.The examples of different multilayers are given,the influence of thickness sensitivity factor on the sensitive spectrum and layer of transmittance are analysed.Finally,a method of defining thickness allowable error is given.
An integral expression for thermal blooming equation of high power laser propagation through atmosphere
Cai Banwei, Huang Wenlong, Liu Zhongyong
1996, 20(4): 240-245.
Abstract:
On the basis of Fresnel Kirchhoff approximation,the integral expression for the thermal blooming of high power lasers propagating through atmosphere has been derived by Green's function method,and numerical simulations of CW steady state thermal blooming have been performed to show the feasibility of our method.We have also shown that the well known Fresnel Kirchhoff diffraction integral is a limiting case of the generalized integral expression,where the refactive index is a constant.
Image edge enhancement with nonlinear effect of Fourier transformation holography
Qin Weiping, Yang Maotian
1996, 20(4): 246-250.
Abstract:
This paper theoretically analyzes the Fourier transformation in a Fourier Fraunhofer holograph system and pint out that the normal first order diffraction efficiency η±1 and the beam intensity ratio k has the relationship: .When k =1,the diffraction effectiveness has the maximum.If k<1,the nonlinear hologram can be recorded.The analysis and experiments proved that the nonlinear effect can yield the edge enhancement.
Research on cooling means of laser amplifer
Guan Fuyi, Lin Kangchun, Meng Shaoxian, Lin Zunqi
1996, 20(4): 250-252.
Abstract:
Laser amplifers are a main means to obtain high power and high energy laser.Laser amplifers are generally pumped by several flashlights in order to increase the output energy.It is critical to design a reasonable cooling means to amplifers for operating at high gain,excellent gain homogeneity,high rate,long lifetime,static and dynamic distortion as possible as small.In the paper,tentative research results on cooling of laser amplifer are presents.
Present development of Cr, Tm, Ho:YAG laser at 2.1μm wavelength
Ye Hongbo, Zhu Changhong, Li Zhengjia
1996, 20(4): 253-256.
Abstract:
In the papter,the Cr,Tm,Ho:YAG Laser at 2.1μm wavelength has been reviewed in terms of dominate and abroad files.The present development of technology of this laser is analyzed in details.