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RSS1999 Vol. 23, No. 5
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1999, 23(5): 257-261.
[Abstract]
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Abstract:
The fundamental principles of ultranarrow band optical filters were described in the paper. The development of optical filters was summarized at present. Meanwhile, the shortages of the both of optical filters were indicated.
The fundamental principles of ultranarrow band optical filters were described in the paper. The development of optical filters was summarized at present. Meanwhile, the shortages of the both of optical filters were indicated.
1999, 23(5): 262-266.
Abstract:
With the rapid development of laser weapons, optical limiting materials have received considerable attention for their application against low energy antipersonnel and antisensor laser weapons. This paper briefly introduced the research of optical limiting and their application in this area in recent years.
With the rapid development of laser weapons, optical limiting materials have received considerable attention for their application against low energy antipersonnel and antisensor laser weapons. This paper briefly introduced the research of optical limiting and their application in this area in recent years.
1999, 23(5): 267-271.
Abstract:
The gas discharge is widely utilized to pump the variety of gas lasers.This paper introduced the transverse magnetically confined technique to maintain the uniform and rapidly rotating glow discharge in a big volume.The system consists of a 500cm×8cm×2cm Rogowsky electrodes,and two rows of magnets are set in the cathode.According to the differences of Lorentz force of discharge particles,the discharge space is divided into three regions.Based on liquid dynamics,this paper set a expression to describe the rotational velocity distribution in discharge region and gave the numerical solution.
The gas discharge is widely utilized to pump the variety of gas lasers.This paper introduced the transverse magnetically confined technique to maintain the uniform and rapidly rotating glow discharge in a big volume.The system consists of a 500cm×8cm×2cm Rogowsky electrodes,and two rows of magnets are set in the cathode.According to the differences of Lorentz force of discharge particles,the discharge space is divided into three regions.Based on liquid dynamics,this paper set a expression to describe the rotational velocity distribution in discharge region and gave the numerical solution.
1999, 23(5): 271-273.
Abstract:
This paper presents Monte Carlo method to simulate the condensation of Cd atoms in He-Cd laser.For the different structures of condensers,the distribution of condensate of Cd atom was obtained. The simulated results indicated the condensation efficiency and the ability of anti-pollution of the condenser.This is useful for design of the metal vapor laser.
This paper presents Monte Carlo method to simulate the condensation of Cd atoms in He-Cd laser.For the different structures of condensers,the distribution of condensate of Cd atom was obtained. The simulated results indicated the condensation efficiency and the ability of anti-pollution of the condenser.This is useful for design of the metal vapor laser.
1999, 23(5): 274-277.
Abstract:
This paper first presents goals and key techniq ues for the design of the controlling system of Nd:YAG medical laser. After pro posing the basic concept of the object-oriented technology, this paper illu strate the object-oriented model of the controlling system for Nd:YAG medical laser. The attributes and the methods for each objects in the model are also discussed in detail in this paper.
This paper first presents goals and key techniq ues for the design of the controlling system of Nd:YAG medical laser. After pro posing the basic concept of the object-oriented technology, this paper illu strate the object-oriented model of the controlling system for Nd:YAG medical laser. The attributes and the methods for each objects in the model are also discussed in detail in this paper.
1999, 23(5): 278-280.
Abstract:
This paper summarized several practical techniques of using laser rainbow holog raphy to realize optical secret coding or anti counterfeiting labels.
This paper summarized several practical techniques of using laser rainbow holog raphy to realize optical secret coding or anti counterfeiting labels.
1999, 23(5): 281-284.
Abstract:
Based on the analysis of the far-field intensity distribution,the beam quality of unstable resonators has been studied in detail.Ithas been proven that the intensity in the far-field of unstable resonato rs is the zeroth order Bessel beam distribution,if the obscure ratio ε→1.N umerical calculation and analysis have shown that the "power in the bucket" curve is a suitable method used to characterize the beam quality in the far-field of unstable resonators.Meanwhile,the shortcomings of this method have been poin ted out.
Based on the analysis of the far-field intensity distribution,the beam quality of unstable resonators has been studied in detail.Ithas been proven that the intensity in the far-field of unstable resonato rs is the zeroth order Bessel beam distribution,if the obscure ratio ε→1.N umerical calculation and analysis have shown that the "power in the bucket" curve is a suitable method used to characterize the beam quality in the far-field of unstable resonators.Meanwhile,the shortcomings of this method have been poin ted out.
1999, 23(5): 284-287.
Abstract:
For design of a high-energy laser system,it is important to measure the absorption properties of optical components.This paper presented calorimetry to measure the optical absorption and discussed the influence of the environmental factors and the interface reflection.As an example,the absorption of GaAs substrate and GaAs high reflective mirror were measured.Finally, the measurement error was analyzed.
For design of a high-energy laser system,it is important to measure the absorption properties of optical components.This paper presented calorimetry to measure the optical absorption and discussed the influence of the environmental factors and the interface reflection.As an example,the absorption of GaAs substrate and GaAs high reflective mirror were measured.Finally, the measurement error was analyzed.
1999, 23(5): 288-291.
Abstract:
The optical lithography using the 193nm excimer-laser is a key technique for decreasing feature size of very large scale integration(VLSI) at the beginning of the next century and has become one of the chal lenge topics in the high-tech research areas.The optical system design,optics materials, excimer-laser source,resists for 193nm and its application in fabrication of CMOS devices are described in this paper.
The optical lithography using the 193nm excimer-laser is a key technique for decreasing feature size of very large scale integration(VLSI) at the beginning of the next century and has become one of the chal lenge topics in the high-tech research areas.The optical system design,optics materials, excimer-laser source,resists for 193nm and its application in fabrication of CMOS devices are described in this paper.
1999, 23(5): 292-295.
Abstract:
Based on the research that was done in Waseda University and Shanghai Jiaotong University,the application of high speed video camera to diesel spray was introduced.Using the characteristics of pulse ruby laser and CCD video camera,the technique of real-time grabbing instantaneous diesel spray image was developed,and some key problems were discussed.
Based on the research that was done in Waseda University and Shanghai Jiaotong University,the application of high speed video camera to diesel spray was introduced.Using the characteristics of pulse ruby laser and CCD video camera,the technique of real-time grabbing instantaneous diesel spray image was developed,and some key problems were discussed.
1999, 23(5): 296-299.
Abstract:
In laser applications,it is a very important problem to define the beam quality of the laser beam,especially for the multi model laser beam.In general, M2 factor is a useful parameter relative to divergence angle and waist diameter of laser beam.If we determined M2,the beam quality parameters of the practical beam,defined with second order moments,would determine.In practice,the precise measurements of these second order moments are difficult.This paser emphasized that beam parameters defined with energy distribution of beam profile are satisfied with ABCD law for stable cavity solid laser,because the output beam is the sum of multi orders of Gaussian lights.The experiments and analysis are well agreeable.
In laser applications,it is a very important problem to define the beam quality of the laser beam,especially for the multi model laser beam.In general, M2 factor is a useful parameter relative to divergence angle and waist diameter of laser beam.If we determined M2,the beam quality parameters of the practical beam,defined with second order moments,would determine.In practice,the precise measurements of these second order moments are difficult.This paser emphasized that beam parameters defined with energy distribution of beam profile are satisfied with ABCD law for stable cavity solid laser,because the output beam is the sum of multi orders of Gaussian lights.The experiments and analysis are well agreeable.
1999, 23(5): 299-303.
Abstract:
In this paper, the history of development of intersatellite optical communicati ons in the countries is retrospected, and it analyzes the developing trend of the technology of intersatellite optical communications. The commercially demand for intersatellite optical communications in the future is introduced and analyzed.
In this paper, the history of development of intersatellite optical communicati ons in the countries is retrospected, and it analyzes the developing trend of the technology of intersatellite optical communications. The commercially demand for intersatellite optical communications in the future is introduced and analyzed.
1999, 23(5): 304-308.
Abstract:
In this paper, using numerical calculation,we analyzed the type Ⅰ/type Ⅱ angle detuning and type Ⅱ/type Ⅱ polarization mismatching third harmonic generation (THG) scheme,and gave the tripling frequency transferring efficiency curves.Meanwhile the laser pulse shape of the fundamental beam is flat in space and Gaussian in time,or extra Gaussian (sixth order) in space and Gaussian in time.With the variation of input intensity from 0 to 10GW/cm2, the tripling transfer efficiency changed,and at the point of 5GW/cm2 the optimum tripling efficiency obtained.This paper has the important reference value to THG experiments for ICF.
In this paper, using numerical calculation,we analyzed the type Ⅰ/type Ⅱ angle detuning and type Ⅱ/type Ⅱ polarization mismatching third harmonic generation (THG) scheme,and gave the tripling frequency transferring efficiency curves.Meanwhile the laser pulse shape of the fundamental beam is flat in space and Gaussian in time,or extra Gaussian (sixth order) in space and Gaussian in time.With the variation of input intensity from 0 to 10GW/cm2, the tripling transfer efficiency changed,and at the point of 5GW/cm2 the optimum tripling efficiency obtained.This paper has the important reference value to THG experiments for ICF.
1999, 23(5): 309-313.
Abstract:
Titanium alloy is a wide used as the blade material in aeroturbine. This paper reported the experimental results of wear capacity of bearing steel GC15 ball on Ti alloy disk processed by laser beam quenching (LBQ) or not,at the friction temperature of room temperature,150℃, 300℃, 450℃.With the increasing of the f riction temperature from room temperature up to 300℃,the wear rate of surface of Ti alloy increased.The scanning electron micrography proved that the large amount of Fe was found in worn zone of Ti alloy.But it was low greatly at 450℃,and the X-ray photography indicated that an oxide film called glazing layer,which consisted of TiO2,Al2O3 and Fe2O3, formed to resist being worn.By using LBQ,the wear resistance of Ti alloy to dry friction at 150℃ and 300℃ was greatly improved, but there was no obvious improvement at room temperatu re and 450℃.
Titanium alloy is a wide used as the blade material in aeroturbine. This paper reported the experimental results of wear capacity of bearing steel GC15 ball on Ti alloy disk processed by laser beam quenching (LBQ) or not,at the friction temperature of room temperature,150℃, 300℃, 450℃.With the increasing of the f riction temperature from room temperature up to 300℃,the wear rate of surface of Ti alloy increased.The scanning electron micrography proved that the large amount of Fe was found in worn zone of Ti alloy.But it was low greatly at 450℃,and the X-ray photography indicated that an oxide film called glazing layer,which consisted of TiO2,Al2O3 and Fe2O3, formed to resist being worn.By using LBQ,the wear resistance of Ti alloy to dry friction at 150℃ and 300℃ was greatly improved, but there was no obvious improvement at room temperatu re and 450℃.
1999, 23(5): 313-315.
Abstract:
Now we have developed a new power-source for continuous light-pumped YAG laser, whose energy consumption is reduced 43% and the non-failure life-span is doubled. The key technology of the new power source is to keep a proper current in Kr lamp.Generally,the current is a very high and the super high voltage is used to make the Kr lamp break down.We analyzed the negative resistant property of Kr lamp and designed a new circuit to reduce the maintenance current from several amps to less one amp.The experimental results show that circuit reduced the power consumption very much.
Now we have developed a new power-source for continuous light-pumped YAG laser, whose energy consumption is reduced 43% and the non-failure life-span is doubled. The key technology of the new power source is to keep a proper current in Kr lamp.Generally,the current is a very high and the super high voltage is used to make the Kr lamp break down.We analyzed the negative resistant property of Kr lamp and designed a new circuit to reduce the maintenance current from several amps to less one amp.The experimental results show that circuit reduced the power consumption very much.
1999, 23(5): 316-318.
Abstract:
For a surface coating technology,the binding strength is an important parameter to indicate the ability of the technology.This paper reported the results of micro shearing experiments to Fe-Cr-Ni alloy,Fe-Cr-Ni(MoS2) alloy coatings.The results show that the shearing strength of the interface between clad layer and substrate is higher than of substrate and clad layer of some alloys.In this experiment,the CW CO2 laser was used,and its output power was 2kW,beam spot was 5mm,cladding speed was 4mm/s.
For a surface coating technology,the binding strength is an important parameter to indicate the ability of the technology.This paper reported the results of micro shearing experiments to Fe-Cr-Ni alloy,Fe-Cr-Ni(MoS2) alloy coatings.The results show that the shearing strength of the interface between clad layer and substrate is higher than of substrate and clad layer of some alloys.In this experiment,the CW CO2 laser was used,and its output power was 2kW,beam spot was 5mm,cladding speed was 4mm/s.
1999, 23(5): 319-323.
Abstract:
In order to change the blind process of laser machining,a new closed-loop control technology is developed in abroad based on realtime testing principle.Therefore,the optimal processing parameters are abtained easily subject to quality cons traints,and the disadvantages of trial-and-error are overcomed.This paper ana lyses the features of kinds control methods and points out the main factors which are considered to select sensor.
In order to change the blind process of laser machining,a new closed-loop control technology is developed in abroad based on realtime testing principle.Therefore,the optimal processing parameters are abtained easily subject to quality cons traints,and the disadvantages of trial-and-error are overcomed.This paper ana lyses the features of kinds control methods and points out the main factors which are considered to select sensor.
