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RSS1994 Vol. 18, No. 6
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1994, 18(6): 322-325.
[Abstract]
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Abstract:
To achieve the uniform discharge in a RF-exited gas laser, reducing the longtitudinal voltage variation is an important problem, According to transmission line theorwe analyze the way to reduce the longtitudinal voltage variation and give out the quantitative calculation method.
To achieve the uniform discharge in a RF-exited gas laser, reducing the longtitudinal voltage variation is an important problem, According to transmission line theorwe analyze the way to reduce the longtitudinal voltage variation and give out the quantitative calculation method.
1994, 18(6): 325-328.
Abstract:
In this paper, the rotating aperture speckle photography used for measuring the dynamic out-of-displacements is proposed. The whole process of the dynamic out-of-displacements of an object can be recorded on a single speckle pattern. And by means of the whole field filtering,the out-of-displacements of every moment can be obtained.
In this paper, the rotating aperture speckle photography used for measuring the dynamic out-of-displacements is proposed. The whole process of the dynamic out-of-displacements of an object can be recorded on a single speckle pattern. And by means of the whole field filtering,the out-of-displacements of every moment can be obtained.
1994, 18(6): 329-334.
Abstract:
To obtain desirable beam energy repartition and enhance the quality of laser beat treatment, many optical systems have been developed in different parts of the world by means of splitting an initial beam and recombining the resulted sub-beams in the interaction plane, Because of the high coherence nature of laser,the energy repartitions of the recombined beams are made much more complicated by the interference and diffraction fringe structures. A detailed analysis of the thermal interaction between laser beam and the target materials is thus becoming more diffcult.In ref.[1],a theoretical calculation based on a simple optical system showed that the influence of the interference and diffraction fringes on the result of laser heat treatment can be neglected and provided that the intervals between these fringes are small relative to the size of the incident beam, and under such circumstances temperature field can be calculated using the energy repartition predicted by geometricaloptics, To genernalize this conclusion,the present paper gives mathematical expressions which can be conveniently used to determine whether or not the interference and diffraction fringes can be safely neglected.The results of experimental verifications are also presented.
To obtain desirable beam energy repartition and enhance the quality of laser beat treatment, many optical systems have been developed in different parts of the world by means of splitting an initial beam and recombining the resulted sub-beams in the interaction plane, Because of the high coherence nature of laser,the energy repartitions of the recombined beams are made much more complicated by the interference and diffraction fringe structures. A detailed analysis of the thermal interaction between laser beam and the target materials is thus becoming more diffcult.In ref.[1],a theoretical calculation based on a simple optical system showed that the influence of the interference and diffraction fringes on the result of laser heat treatment can be neglected and provided that the intervals between these fringes are small relative to the size of the incident beam, and under such circumstances temperature field can be calculated using the energy repartition predicted by geometricaloptics, To genernalize this conclusion,the present paper gives mathematical expressions which can be conveniently used to determine whether or not the interference and diffraction fringes can be safely neglected.The results of experimental verifications are also presented.
1994, 18(6): 335-343.
Abstract:
Choosing KCl:Li FA(Ⅱ) centre as a representative of color centre laser materials,we analyze the features of KCl-LiCl and other doping system related to KCl base materials from the view point of physical chemistry,in this paper.The maincharacteristics of KCl:Li FA(Ⅱ) color center laser crystal are reviewed,and thepreparation of color centerlaser crystals is briefly summarized.
Choosing KCl:Li FA(Ⅱ) centre as a representative of color centre laser materials,we analyze the features of KCl-LiCl and other doping system related to KCl base materials from the view point of physical chemistry,in this paper.The maincharacteristics of KCl:Li FA(Ⅱ) color center laser crystal are reviewed,and thepreparation of color centerlaser crystals is briefly summarized.
1994, 18(6): 344-347.
Abstract:
When a CCD detector is locally irradiated with a laser,the working features of the CCD detector will vary in laser energy density. Extremely,the CCD detector will be damaged. The saturation thresholds of CCD detector,irradiatedwith a CW 1060 nm or 632.8 nm laser, have been measured respectively,The mechanism of saturation and damage of CCD detector have been discussed in this paper. By employing one dimension non-conducting boundary condition,the thermal saturation threshold hasbeen calculated.
When a CCD detector is locally irradiated with a laser,the working features of the CCD detector will vary in laser energy density. Extremely,the CCD detector will be damaged. The saturation thresholds of CCD detector,irradiatedwith a CW 1060 nm or 632.8 nm laser, have been measured respectively,The mechanism of saturation and damage of CCD detector have been discussed in this paper. By employing one dimension non-conducting boundary condition,the thermal saturation threshold hasbeen calculated.
1994, 18(6): 348-352.
Abstract:
In this paper, several damage mechanisms of optical dielectric films by high power laser are summarized; The damage action of laser plasma to films and the shock wave producing while the plasma is expanding are emphasized.
In this paper, several damage mechanisms of optical dielectric films by high power laser are summarized; The damage action of laser plasma to films and the shock wave producing while the plasma is expanding are emphasized.
1994, 18(6): 352-356.
Abstract:
This paper introduces a new type Cs atomic resonance filter(ARF)detected by photoionization. The theoretical analysis gives the inherent time response of 10 ns,the linewidth of 62 MHz and quantum efficiency of 86.6%. In current experimental apparatus, the preliminary measurements give ARF’s time response of 130 ns,quantum efficiency greater than 10.1%and critical signal laser energy of 3 nJ.A better results will be obtained while the experimental apparatus improved.
This paper introduces a new type Cs atomic resonance filter(ARF)detected by photoionization. The theoretical analysis gives the inherent time response of 10 ns,the linewidth of 62 MHz and quantum efficiency of 86.6%. In current experimental apparatus, the preliminary measurements give ARF’s time response of 130 ns,quantum efficiency greater than 10.1%and critical signal laser energy of 3 nJ.A better results will be obtained while the experimental apparatus improved.
1994, 18(6): 357-360.
Abstract:
On the basis of brief analysis of major factors, that affect the accuracy of laser collimator,the laser alignment principle by using a single mode fiber is presented in this paper.The design of softwareand hardware is discussed. The experimental results on the laser drift of the collimator is given and indicate that the relative laser drift of the collimator within the range of 20 meters in one hour is less than 2×10-6.
On the basis of brief analysis of major factors, that affect the accuracy of laser collimator,the laser alignment principle by using a single mode fiber is presented in this paper.The design of softwareand hardware is discussed. The experimental results on the laser drift of the collimator is given and indicate that the relative laser drift of the collimator within the range of 20 meters in one hour is less than 2×10-6.
1994, 18(6): 361-365.
Abstract:
Production of surface pressure,plasma formation and momentum transfer of target is analyzed in interaction between laser and target material in this paper,a low-energy and high-power 1.06μm YAG laser with a pulse width of 15 ns is applied to act upon different target material surfaces,and by using a pendulum shift technique to measure displacement of the target surface,momentum transfer and momentum coupling coefficient are obtained at different conditions.
Production of surface pressure,plasma formation and momentum transfer of target is analyzed in interaction between laser and target material in this paper,a low-energy and high-power 1.06μm YAG laser with a pulse width of 15 ns is applied to act upon different target material surfaces,and by using a pendulum shift technique to measure displacement of the target surface,momentum transfer and momentum coupling coefficient are obtained at different conditions.
1994, 18(6): 366-369.
Abstract:
In this paper,a method of measuring the spectroscopic width of pulsed laser using scanning etalon as well as detecting system is introuduced;the factors relative to measurement error are analyse.And the spectroscopic widths of three pulsed dye lasers are measured in this way.
In this paper,a method of measuring the spectroscopic width of pulsed laser using scanning etalon as well as detecting system is introuduced;the factors relative to measurement error are analyse.And the spectroscopic widths of three pulsed dye lasers are measured in this way.
1994, 18(6): 370-374.
Abstract:
This paper analyzes the thermal characteristics of tube laser crystal in different cooling conditions. The relations of stress limit to relative thickness of tube are obtained. The relations show that the proper selection of thickness and cooling conditions can make the damage limit much higher than red crystals.
This paper analyzes the thermal characteristics of tube laser crystal in different cooling conditions. The relations of stress limit to relative thickness of tube are obtained. The relations show that the proper selection of thickness and cooling conditions can make the damage limit much higher than red crystals.
1994, 18(6): 375-378.
Abstract:
In polycrystalline materials,there are three phenomena:the scattering in crystal boundary, the phase change scattering,the air cell scattering. Actually, the index variation of the observed material unit,relative to the adjacent medium,always exists.According to this consideration,the scattering effect as the function of index change is obtained in terms of the diffraction analysis.
In polycrystalline materials,there are three phenomena:the scattering in crystal boundary, the phase change scattering,the air cell scattering. Actually, the index variation of the observed material unit,relative to the adjacent medium,always exists.According to this consideration,the scattering effect as the function of index change is obtained in terms of the diffraction analysis.
1994, 18(6): 379-381.
Abstract:
In this paper, the design and experimental study of two electron-optical Q-switch circuits for Nd:YAG laser at repetition rate 40pps are presented. The com-parison of the circuits is reported.
In this paper, the design and experimental study of two electron-optical Q-switch circuits for Nd:YAG laser at repetition rate 40pps are presented. The com-parison of the circuits is reported.
1994, 18(6): 382-384.
Abstract:
This paper reports the different operation methods,treated 1000 cases with lasers. The treatment results are generally satisfactory, The procedure has the advantages of simple, less trauma,safe and carrying out with less operative complication.
This paper reports the different operation methods,treated 1000 cases with lasers. The treatment results are generally satisfactory, The procedure has the advantages of simple, less trauma,safe and carrying out with less operative complication.
