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RSS1998 Vol. 22, No. 1
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1998, 22(1): 1-3.
[Abstract]
[PDF 700KB]
Abstract:
In general,the measurement of surface profile of a high temperature body is a difficult problem.We employed a laser radar system,including a laser phase rangefinder,to measure the surface profile of a hot body,and achieved the better measurement precision of 1 cm.In order to achieve higher SNR,we used the view field matching technology of laser emission and receiving,the technologies of laser beam intensity modulation,phase discrimination,and high sensitive APD detector.
In general,the measurement of surface profile of a high temperature body is a difficult problem.We employed a laser radar system,including a laser phase rangefinder,to measure the surface profile of a hot body,and achieved the better measurement precision of 1 cm.In order to achieve higher SNR,we used the view field matching technology of laser emission and receiving,the technologies of laser beam intensity modulation,phase discrimination,and high sensitive APD detector.
1998, 22(1): 3-7.
Abstract:
This paper introduces the physical mechanism of laser damage of metal materials and isolation materials,assisted by the DC spark discharge,and discusses the relation of DC spark discharge factors and the laser parameters,effecting on the laser cutting and laser drilling.A experimental setup is established to analysis the electrode arrangement and spark factors and to fined the optimum match of DC discharge factors and laser parameters.The experiment results show that the quality of laser cutting and laser drilling with DC spark discharge will considerably improve and the technique can be widely used in laser processing.
This paper introduces the physical mechanism of laser damage of metal materials and isolation materials,assisted by the DC spark discharge,and discusses the relation of DC spark discharge factors and the laser parameters,effecting on the laser cutting and laser drilling.A experimental setup is established to analysis the electrode arrangement and spark factors and to fined the optimum match of DC discharge factors and laser parameters.The experiment results show that the quality of laser cutting and laser drilling with DC spark discharge will considerably improve and the technique can be widely used in laser processing.
1998, 22(1): 8-10.
Abstract:
This psper described a laser diode frequence stabilization system composed of a precisely temperature control system and a operating current control system of the laser diode.Using the first defferential signal of the resonance line,the operating frequence of the laser diode can be locked to D2 line of 85Rb.The measurement results show that the frequence stability evaluated by Allan variance is 10-9order for 10 seconds sampling time.
This psper described a laser diode frequence stabilization system composed of a precisely temperature control system and a operating current control system of the laser diode.Using the first defferential signal of the resonance line,the operating frequence of the laser diode can be locked to D2 line of 85Rb.The measurement results show that the frequence stability evaluated by Allan variance is 10-9order for 10 seconds sampling time.
1998, 22(1): 11-14.
Abstract:
Base on the theoretical analysis,the YBa2Cu3-xZnxO7 thin film infrared detector has been designed and manufactured.The properties of the detector has been measured at 77°K and are well agreement with design,as follow:Rv(500,10,1)=3587V/W,NEP(500,10,1)=6.5×10-12W/Hz1/2,D*(500,10,1)=7.2×1012cmHz1/2/W,τ(500,10,1)=1.2ms.
Base on the theoretical analysis,the YBa2Cu3-xZnxO7 thin film infrared detector has been designed and manufactured.The properties of the detector has been measured at 77°K and are well agreement with design,as follow:Rv(500,10,1)=3587V/W,NEP(500,10,1)=6.5×10-12W/Hz1/2,D*(500,10,1)=7.2×1012cmHz1/2/W,τ(500,10,1)=1.2ms.
1998, 22(1): 14-17.
Abstract:
Starting from the M2-factor concept,the beam quality of high power lasers,typical examples of which are lasers propagating through ICF driver and laser power beaming,has been analyzed.Some aspects concerning the beam quality definition and measurement methods of high-power lasers have also been discussed.
Starting from the M2-factor concept,the beam quality of high power lasers,typical examples of which are lasers propagating through ICF driver and laser power beaming,has been analyzed.Some aspects concerning the beam quality definition and measurement methods of high-power lasers have also been discussed.
1998, 22(1): 18-21.
Abstract:
In this paper,based on Mie scattering and Fraunhofer diffraction theory,we utilize the numerical calculation to compare and analyze the Mie scattering and Fraunhofer diffraction of large particles and point out that at a proper range,Fraunhofer diffraction of large particles can approximately replace Mie scattering.
In this paper,based on Mie scattering and Fraunhofer diffraction theory,we utilize the numerical calculation to compare and analyze the Mie scattering and Fraunhofer diffraction of large particles and point out that at a proper range,Fraunhofer diffraction of large particles can approximately replace Mie scattering.
1998, 22(1): 22-25.
Abstract:
Non-differaction beam is a new research field which has been given more and more attention recently both at home and abroad.It has properties of long focus depth and small central spot.For these properties,the authors apply it as incident beam to resolve the main problem in traditional laser triangulation measurement,which is high resolution and large measurement rang can not be satisfied meantime.Theory and generation method of non-diffraction beam have been given.Basing on the relationship of object-image position,structure parameters of the laser triangulation measurement system with non-diffraction beam has been designed and the experimental results have been given.The theoretical analysis and experimental results show that the novel system is better than the traditional triangulation systems clearly.
Non-differaction beam is a new research field which has been given more and more attention recently both at home and abroad.It has properties of long focus depth and small central spot.For these properties,the authors apply it as incident beam to resolve the main problem in traditional laser triangulation measurement,which is high resolution and large measurement rang can not be satisfied meantime.Theory and generation method of non-diffraction beam have been given.Basing on the relationship of object-image position,structure parameters of the laser triangulation measurement system with non-diffraction beam has been designed and the experimental results have been given.The theoretical analysis and experimental results show that the novel system is better than the traditional triangulation systems clearly.
1998, 22(1): 26-29.
Abstract:
This paper report an investigation of laser beam butt-welding of zinc coated sheet for automobile use.The effects of the vaporization of zinc on the plasma formation are discussed.It is shown that the laser beam mode and the plasma-controlling gas flow rate are the most important parameters for obtaining a high quality joint.Successful butt joint beads with similar mechanical property to that of the base metal were obtained.
This paper report an investigation of laser beam butt-welding of zinc coated sheet for automobile use.The effects of the vaporization of zinc on the plasma formation are discussed.It is shown that the laser beam mode and the plasma-controlling gas flow rate are the most important parameters for obtaining a high quality joint.Successful butt joint beads with similar mechanical property to that of the base metal were obtained.
1998, 22(1): 29-33.
Abstract:
The characteristics of multielement optical resonators,in particular,the resonator with an internal lens and telescopic resonator which can be represented in terms of fractional Fourier transforms(FRFTs) have been studied by means of the ABCD matrix method.Then,starting from the generalized Huygens-Fresnel diffraction integral,the two-dimensional diffraction integral of optical resonators expressed as FRFTs has been derived and the corresponding matrix formulation has been given and discussed.
The characteristics of multielement optical resonators,in particular,the resonator with an internal lens and telescopic resonator which can be represented in terms of fractional Fourier transforms(FRFTs) have been studied by means of the ABCD matrix method.Then,starting from the generalized Huygens-Fresnel diffraction integral,the two-dimensional diffraction integral of optical resonators expressed as FRFTs has been derived and the corresponding matrix formulation has been given and discussed.
1998, 22(1): 34-36.
Abstract:
After adjusting components of the Fe-Cr-Ni alloy powder whichis used to laser clad on 45 steel,we find that the expansion coefficient of clad layer and it's cracking sensitivity have been changed,and the cracking sensitivity decrease with lowering of expansion coefficient of clad layer.In this paper we discusse these results and point out that proper selecting the range of the difference of expansion coefficient between clad layer and substrate is beneficial to reduce cracking sensitivity of clad layer.
After adjusting components of the Fe-Cr-Ni alloy powder whichis used to laser clad on 45 steel,we find that the expansion coefficient of clad layer and it's cracking sensitivity have been changed,and the cracking sensitivity decrease with lowering of expansion coefficient of clad layer.In this paper we discusse these results and point out that proper selecting the range of the difference of expansion coefficient between clad layer and substrate is beneficial to reduce cracking sensitivity of clad layer.
1998, 22(1): 37-41.
Abstract:
The laser scanning confocal fluorescent microscope has the feature of high longitudinal resolution power and can provide clear 2-dimension or 3-dimension medical image.The purpose of this paper is to introduce the optical design,imaging principles and key points of design of the laser scanning confocal fluorescent microscope system.To achieve high quality imaging,it is important to realize the precision laser optical scanner and optimize the design of imaging components.
The laser scanning confocal fluorescent microscope has the feature of high longitudinal resolution power and can provide clear 2-dimension or 3-dimension medical image.The purpose of this paper is to introduce the optical design,imaging principles and key points of design of the laser scanning confocal fluorescent microscope system.To achieve high quality imaging,it is important to realize the precision laser optical scanner and optimize the design of imaging components.
1998, 22(1): 41-43.
Abstract:
A novel method to fabricate TM pass polarizers-introducing proton exchange regions adjacent to Ti:LiNbO3 waveguide-has been presented.A two dimension BMP has been used to obtain the characteristics of the TM pass polarizer,which depend on the length,width and gap of the proton exchange region.The results of the design calculation were given.The extinction factor of 51dB was realized for TM-pass polarizers.
A novel method to fabricate TM pass polarizers-introducing proton exchange regions adjacent to Ti:LiNbO3 waveguide-has been presented.A two dimension BMP has been used to obtain the characteristics of the TM pass polarizer,which depend on the length,width and gap of the proton exchange region.The results of the design calculation were given.The extinction factor of 51dB was realized for TM-pass polarizers.
1998, 22(1): 44-45.
Abstract:
XW1 military solid laser cooling fluids can be used in the repaeted frequency solid laser.It's adaption to the temperature from -65℃ to 99℃.Large specific heat,high heat-transfer coefficient and no corrsion to the cooling system are the obviously advantage.The cooling fluids is composed of LiCl and H2O,with a small amount of preservative agent.In order to enhence heat-transfer coefficient,some organic agent is added.
XW1 military solid laser cooling fluids can be used in the repaeted frequency solid laser.It's adaption to the temperature from -65℃ to 99℃.Large specific heat,high heat-transfer coefficient and no corrsion to the cooling system are the obviously advantage.The cooling fluids is composed of LiCl and H2O,with a small amount of preservative agent.In order to enhence heat-transfer coefficient,some organic agent is added.
1998, 22(1): 46-49.
Abstract:
This paper presents the experimental research on the TiC-WC-Co metal ceramic alloy cladded on No.45 steel surface by using a high power CO2 laser.The microstructure or hardness of the cladding layer is subjected to the effects of laser energy density and scanning speed.Furthermore,the preliminary discussion on the mechanism of metal ceramic alloy resulted from laser cladding is also given.
This paper presents the experimental research on the TiC-WC-Co metal ceramic alloy cladded on No.45 steel surface by using a high power CO2 laser.The microstructure or hardness of the cladding layer is subjected to the effects of laser energy density and scanning speed.Furthermore,the preliminary discussion on the mechanism of metal ceramic alloy resulted from laser cladding is also given.
1998, 22(1): 49-51.
Abstract:
Using 6328nm red light,we have made the experimental studies to two wave light coupling in Ce:KNSBN single crystal and demonstrate that the gain coefficientΓof two-wave coupling is a function of the crossing angle 2θ of two beams.According to fitting of Γ-2θ experimental data,the effective photo refractive charge density,the effective electro optical coefficient and the hole electron competition factor have been derived.These results are useful to optical information processing.
Using 6328nm red light,we have made the experimental studies to two wave light coupling in Ce:KNSBN single crystal and demonstrate that the gain coefficientΓof two-wave coupling is a function of the crossing angle 2θ of two beams.According to fitting of Γ-2θ experimental data,the effective photo refractive charge density,the effective electro optical coefficient and the hole electron competition factor have been derived.These results are useful to optical information processing.
1998, 22(1): 52-54.
Abstract:
This paper introduces a position sensitive detector and a non contact position detection system.The system include a laser diode light source,a imaging optical system and a image position sensitive detector.The surface of a body is illuminated with the light source and imaged on the sensitive surface of the detector.According to the relationship between the body and its image,the deviation of the body can be calculated.The measurement accuracy of the deviation depends on the position discriminativity.In our system,the position discriminativity of the detector is 2 micron,the measurement error is less than 5 micron.
This paper introduces a position sensitive detector and a non contact position detection system.The system include a laser diode light source,a imaging optical system and a image position sensitive detector.The surface of a body is illuminated with the light source and imaged on the sensitive surface of the detector.According to the relationship between the body and its image,the deviation of the body can be calculated.The measurement accuracy of the deviation depends on the position discriminativity.In our system,the position discriminativity of the detector is 2 micron,the measurement error is less than 5 micron.
