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RSS1995 Vol. 19, No. 5
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1995, 19(5): 259-260.
[Abstract]
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Abstract:
1995, 19(5): 261-263.
Abstract:
A new gas laser1kW TEMOO CO2 laserexcited by the confined discharge has been studied in this paper. The confined discharge means that in the process of laser discharge,the or-thogonal electrical and electrical fields or orthogonal magnetic and electrical fields on the surface of cath-ode are used to confined electrons and ions in a trap or many traps of well designed shape. As an example of the applications of this excitation method,high efficient and high power CO2 CW laser,in which the transverse magnetic field perpendicular to electrical field was used,has been studied in detail.
A new gas laser1kW TEMOO CO2 laserexcited by the confined discharge has been studied in this paper. The confined discharge means that in the process of laser discharge,the or-thogonal electrical and electrical fields or orthogonal magnetic and electrical fields on the surface of cath-ode are used to confined electrons and ions in a trap or many traps of well designed shape. As an example of the applications of this excitation method,high efficient and high power CO2 CW laser,in which the transverse magnetic field perpendicular to electrical field was used,has been studied in detail.
1995, 19(5): 264-266.
Abstract:
A CO2 laser fluid recycle control system is described in this paper. The used structrure and programmable control means in this system permit not only the accurate control and maintenance of gas pressure substantially constant in CO2 laser but also the automatically adjustment of the fluid exchange volume and the different compositions of supplied mixed fluid according to the laser working sta-tus(CW or Pulse)and its output power.All parameters can be preset before the operation of the laser and can be conveniently,precisely and selectively varied at any time of the operation.
A CO2 laser fluid recycle control system is described in this paper. The used structrure and programmable control means in this system permit not only the accurate control and maintenance of gas pressure substantially constant in CO2 laser but also the automatically adjustment of the fluid exchange volume and the different compositions of supplied mixed fluid according to the laser working sta-tus(CW or Pulse)and its output power.All parameters can be preset before the operation of the laser and can be conveniently,precisely and selectively varied at any time of the operation.
1995, 19(5): 267-270.
Abstract:
This paper introduces the cooling system and over-temperature protection.it is consider-ablly useful for practice.
This paper introduces the cooling system and over-temperature protection.it is consider-ablly useful for practice.
1995, 19(5): 271-273.
Abstract:
An new way to analyse the laser resonator-Finite Element Method(FEM)is presented.The mode of CO2 continuous wave laser resonator is calculated by FEM and compared with Fox-Li nu-merical method and matrix multiplying method.
An new way to analyse the laser resonator-Finite Element Method(FEM)is presented.The mode of CO2 continuous wave laser resonator is calculated by FEM and compared with Fox-Li nu-merical method and matrix multiplying method.
1995, 19(5): 274-276.
Abstract:
The paper discusses high frequency discharge with dielectric electrode,emphasizing on the basic issues relating to the influence of frequency,dielectric constant on discharge and impedance match.
The paper discusses high frequency discharge with dielectric electrode,emphasizing on the basic issues relating to the influence of frequency,dielectric constant on discharge and impedance match.
1995, 19(5): 276-279.
Abstract:
The performance of heat exchange is an essential technology to assure the long time stable work of high power CO2 lasers. In this paper,the calculation of heat exchange and the design of radi-ator are described in detail,which use the radiators made of elliptical tubes with fins as examples.
The performance of heat exchange is an essential technology to assure the long time stable work of high power CO2 lasers. In this paper,the calculation of heat exchange and the design of radi-ator are described in detail,which use the radiators made of elliptical tubes with fins as examples.
1995, 19(5): 280-283.
Abstract:
The effects of variety of gravity direction on laser processing are studied in the paper.The melting zone has a tendency moving along with the gravity direction,so it has a different surface when the gravity direction is different.The lower the gradient of temperature on the surface,the clearer these effects.
The effects of variety of gravity direction on laser processing are studied in the paper.The melting zone has a tendency moving along with the gravity direction,so it has a different surface when the gravity direction is different.The lower the gradient of temperature on the surface,the clearer these effects.
1995, 19(5): 283-285.
Abstract:
The Excime laser ablation of Magnesium oxide crystal was studied by emission spec-troscopy and ion probe diagnostic techniques. The experiment results show that the main particle species existed in the laser ablated plasma are Mg atoms and Mg+ ions. and their kinetic energy is in the range of 30 to 45eV. A threshold fluence for significant material removal of 3 J/cm2 was determined by ablation depth rate measurement.and below this value,surface damage in the form of micro-crack was observed.
The Excime laser ablation of Magnesium oxide crystal was studied by emission spec-troscopy and ion probe diagnostic techniques. The experiment results show that the main particle species existed in the laser ablated plasma are Mg atoms and Mg+ ions. and their kinetic energy is in the range of 30 to 45eV. A threshold fluence for significant material removal of 3 J/cm2 was determined by ablation depth rate measurement.and below this value,surface damage in the form of micro-crack was observed.
1995, 19(5): 286-289.
Abstract:
In this paper,we analyzed principle of a simultaneously active mode-locked and Q-switched Nd:YAG laser.This system generates pulse width of 172ps and pulse peak power of 305kW with good stability and reliability. The peak power is 103 time as large as the peak power of mode-locked laser.
In this paper,we analyzed principle of a simultaneously active mode-locked and Q-switched Nd:YAG laser.This system generates pulse width of 172ps and pulse peak power of 305kW with good stability and reliability. The peak power is 103 time as large as the peak power of mode-locked laser.
1995, 19(5): 289-292.
Abstract:
In this paper,from the point of material processing,we have discussed the possibility of using M2 factor to evaluate laser beam quality,It has been pointed out that M2 factor is suitable for evaluation of beam quality in the so-called penetrating processing(i. e. weldding,cuting.drilling,etc.),but it's not suitable in the so-called surface processing(i. e. surface heat treatment.marking,etc.)
In this paper,from the point of material processing,we have discussed the possibility of using M2 factor to evaluate laser beam quality,It has been pointed out that M2 factor is suitable for evaluation of beam quality in the so-called penetrating processing(i. e. weldding,cuting.drilling,etc.),but it's not suitable in the so-called surface processing(i. e. surface heat treatment.marking,etc.)
1995, 19(5): 292-295.
Abstract:
A method, laser scanning ablation,for deposition of well-distributed high Tc supercon-ductivity(HTSC)films over large area was presented,and a mathemathtical model for the method was established.By means of mathmatics analysis,it was shown that the distribution of film thickness depended on the laser scanning radius and the distance between substrate and target.Also indicated by the analysis results,there was an optimum scanning radius for achieving a maximum film in the range of requisite uniforinity. And the results were agreed with experiments.
A method, laser scanning ablation,for deposition of well-distributed high Tc supercon-ductivity(HTSC)films over large area was presented,and a mathemathtical model for the method was established.By means of mathmatics analysis,it was shown that the distribution of film thickness depended on the laser scanning radius and the distance between substrate and target.Also indicated by the analysis results,there was an optimum scanning radius for achieving a maximum film in the range of requisite uniforinity. And the results were agreed with experiments.
1995, 19(5): 296-298.
Abstract:
The characteristics of the optical filters were studied.When the circumferential temperature is changing or the incident angle was deviation from normal angle 0,the shiftlaw of ceteral wave-length and whole curve-shape of the optical-fillter character were given. Also the practical skill of the operation process was described.
The characteristics of the optical filters were studied.When the circumferential temperature is changing or the incident angle was deviation from normal angle 0,the shiftlaw of ceteral wave-length and whole curve-shape of the optical-fillter character were given. Also the practical skill of the operation process was described.
1995, 19(5): 299-301.
Abstract:
In this paper,stimulated Raman scattering(SRS)is observed when multi-mode optical fibers are pumped by YAG laser.The wavelength of the Stokes beams is obstained by the SRS spectra-graph and the Raman frequency shift is calculated.The phenomena in the experiment are analyzed and discussed.
In this paper,stimulated Raman scattering(SRS)is observed when multi-mode optical fibers are pumped by YAG laser.The wavelength of the Stokes beams is obstained by the SRS spectra-graph and the Raman frequency shift is calculated.The phenomena in the experiment are analyzed and discussed.
1995, 19(5): 301-303.
Abstract:
In this review,the application and prospect of laser research on medicine and clinical therapy are introduced systematically. The interdependent relationship of laser therapy with medical laser instrument and related subject is analyzed emphatically. In the last part of the article,our efforts and progress on the research,development and production of medical laser instruments are described briefly.
In this review,the application and prospect of laser research on medicine and clinical therapy are introduced systematically. The interdependent relationship of laser therapy with medical laser instrument and related subject is analyzed emphatically. In the last part of the article,our efforts and progress on the research,development and production of medical laser instruments are described briefly.
1995, 19(5): 304-305.
Abstract:
In process of making polycrystalline sillicon solar cell material,the microstructure defect of material surface worsenes electric character of material and reduces minority carrier life because of ion injecting and maching.To solve this problem,the sillicon material was scanned by high power CO2 laser,and crystal extension was obtained and defect was eliminated in experiment.The block resistance of material surface was reduced and minority carrier life was increased.The type reversal of material scanned by laser was also analysed.
In process of making polycrystalline sillicon solar cell material,the microstructure defect of material surface worsenes electric character of material and reduces minority carrier life because of ion injecting and maching.To solve this problem,the sillicon material was scanned by high power CO2 laser,and crystal extension was obtained and defect was eliminated in experiment.The block resistance of material surface was reduced and minority carrier life was increased.The type reversal of material scanned by laser was also analysed.
1995, 19(5): 306-308.
Abstract:
This paper analyses the trouble phenomena often appeared in a portable RF excited CO2 laser,and introduces the relative protective methodes. All of these has a considerablly referential value for practice.
This paper analyses the trouble phenomena often appeared in a portable RF excited CO2 laser,and introduces the relative protective methodes. All of these has a considerablly referential value for practice.
1995, 19(5): 308-310.
Abstract:
This paper provides the adither matrix algorithm to carve the poly-gray level image onthe laser carving machine. In addition,it introduces some kinds of the TIF image file.
This paper provides the adither matrix algorithm to carve the poly-gray level image onthe laser carving machine. In addition,it introduces some kinds of the TIF image file.
1995, 19(5): 311-313.
Abstract:
A laser cladding has been processed on the 30CrMnSiNi2A which is often used in mading plane landing gear by using three kinds of alloy powder,and the contact fatigue erosion test is done with the high-frequence queching sample,then the wearing resistance is compared by using the method of weight loss. The microhardness distribution,microstructure and properties of cladding and transition layer of nickel-based alloysample are analysed.The results show:the wearing resistance can be greater improved by laser cladding process,among these three kinds of alloy powder,the wearability of Ni+ 30% WC is the best.
A laser cladding has been processed on the 30CrMnSiNi2A which is often used in mading plane landing gear by using three kinds of alloy powder,and the contact fatigue erosion test is done with the high-frequence queching sample,then the wearing resistance is compared by using the method of weight loss. The microhardness distribution,microstructure and properties of cladding and transition layer of nickel-based alloysample are analysed.The results show:the wearing resistance can be greater improved by laser cladding process,among these three kinds of alloy powder,the wearability of Ni+ 30% WC is the best.
1995, 19(5): 314-316.
Abstract:
This paper analysed the formation mechanism of plasma in high-power CO2 laser welding,and systematically summarized the controlling methods for plasma. Finnally,discussed the role of assist-gas for plasma.
This paper analysed the formation mechanism of plasma in high-power CO2 laser welding,and systematically summarized the controlling methods for plasma. Finnally,discussed the role of assist-gas for plasma.
1995, 19(5): 317-319.
Abstract:
This paper introduces the principle of carving the black and white image on the laser carving machine.In addition,it gives the reasons that the laser eats some parts of the carvings. The extention-zero-point algorithm is provided to solve the problem.
This paper introduces the principle of carving the black and white image on the laser carving machine.In addition,it gives the reasons that the laser eats some parts of the carvings. The extention-zero-point algorithm is provided to solve the problem.
1995, 19(5): 319-310.
Abstract:
This paper reported the experiment that used excimer laser(308nm,28ns)to clean the surface of Si substrate. The influnce of laser energy density on laser cleaning was studied. During the test,the energy density irrated on the substrate surface was altered by changing the size of the light beam or adjusting the output energy of the laser.The result obtained was that the cleaning threshold of Si substrate is 0.2J/cm2,while the damage threshold of it is 1.2J/cm2.
This paper reported the experiment that used excimer laser(308nm,28ns)to clean the surface of Si substrate. The influnce of laser energy density on laser cleaning was studied. During the test,the energy density irrated on the substrate surface was altered by changing the size of the light beam or adjusting the output energy of the laser.The result obtained was that the cleaning threshold of Si substrate is 0.2J/cm2,while the damage threshold of it is 1.2J/cm2.
