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RSS1997 Vol. 21, No. 2
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1997, 21(2): 71-74.
[Abstract]
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Abstract:
Absolute distance interferometry (ADI) for large length measurements has been studied for several decades.In this period,many breakthroughs in ADI art have been achieved.Recent years,this technique has came to maturity in the subject of long distance measurement.Starting from the point of the detailed description of ADI principles,this paper reviews the development history of ADI,analyses the current state and future trends of ADI emphasizes the application of the multiwavelength infrared lasers in this subject.
Absolute distance interferometry (ADI) for large length measurements has been studied for several decades.In this period,many breakthroughs in ADI art have been achieved.Recent years,this technique has came to maturity in the subject of long distance measurement.Starting from the point of the detailed description of ADI principles,this paper reviews the development history of ADI,analyses the current state and future trends of ADI emphasizes the application of the multiwavelength infrared lasers in this subject.
1997, 21(2): 74-76.
Abstract:
This paper compared several methods of making the photoresist embossing holographic master and gave out the evaluation.The one-step imaging process provide the functions of the better effect and simple process,but the method needs huge investment.For one-step direct method,it is essential to have a two dimension pattern plate with high resolution,high contrast and low noise.Otherwise than one-step imaging process,the one-step direct method needn't high quality equipments,so the investmen is lower.The one-step projection method can not provide better effect and is seriously restricted by the operating condition,so the method is used only when others can not be used.Owing to the aberration of master and lower utilization ratio of light energy,the two-step method is used only as an auxi liary means of one-step direct method.
This paper compared several methods of making the photoresist embossing holographic master and gave out the evaluation.The one-step imaging process provide the functions of the better effect and simple process,but the method needs huge investment.For one-step direct method,it is essential to have a two dimension pattern plate with high resolution,high contrast and low noise.Otherwise than one-step imaging process,the one-step direct method needn't high quality equipments,so the investmen is lower.The one-step projection method can not provide better effect and is seriously restricted by the operating condition,so the method is used only when others can not be used.Owing to the aberration of master and lower utilization ratio of light energy,the two-step method is used only as an auxi liary means of one-step direct method.
1997, 21(2): 77-80.
Abstract:
High power LD is directly coupled to the multi-mode optical fiber whose end is uptapered by polishing.Some main factors affecting the coupling efficiency are analysed.Proposed is a novel method of carrying out the direct coupling,with the help of the tool-maker's microscope, a coupling efficiency of higher than 50.8 percent is obtained.
High power LD is directly coupled to the multi-mode optical fiber whose end is uptapered by polishing.Some main factors affecting the coupling efficiency are analysed.Proposed is a novel method of carrying out the direct coupling,with the help of the tool-maker's microscope, a coupling efficiency of higher than 50.8 percent is obtained.
1997, 21(2): 81-83.
Abstract:
Using a integrating sphere designed by ourselves,we measured the thermal coupling coefficients of several kinds of LY12 Al alloy targets having different surface situations to CW CO2 laser beam(the power is about 40W).The experiment results show the fact that the test values are bigger than the calculation values by the classical theory.This paper presented the analysis to the fact,and points out the surface defects will much increase the thermal coupling coefficient.
Using a integrating sphere designed by ourselves,we measured the thermal coupling coefficients of several kinds of LY12 Al alloy targets having different surface situations to CW CO2 laser beam(the power is about 40W).The experiment results show the fact that the test values are bigger than the calculation values by the classical theory.This paper presented the analysis to the fact,and points out the surface defects will much increase the thermal coupling coefficient.
1997, 21(2): 83-86.
Abstract:
In general,the surface scattering will influence on the visibility of the holographic interferogram.Some times,the influence is so serious that it is almost not possible to recognize the object displayed in interferogram.As well as a complicated object,the visibility of the holographic interferograms of the printed circuit board have be getting lower by the scattering of the surface and solder joints.This paper presented a fringe detection method in a slide windows to reconstruct the interferogram fringe.With the method,it is possible correctly to decide the location of the solder joints.
In general,the surface scattering will influence on the visibility of the holographic interferogram.Some times,the influence is so serious that it is almost not possible to recognize the object displayed in interferogram.As well as a complicated object,the visibility of the holographic interferograms of the printed circuit board have be getting lower by the scattering of the surface and solder joints.This paper presented a fringe detection method in a slide windows to reconstruct the interferogram fringe.With the method,it is possible correctly to decide the location of the solder joints.
1997, 21(2): 87-91.
Abstract:
Surface remelting,surface alloying and surface cladding are 3 essential processes in the surface modification of aluminium alloy by laser.They are distinctive,but there are some relations each other too.Through testing their microstructures and hardening effects are investigated and contrasted.The study can give guidance for the research and application of surface laser strengthening processes of aluminium alloy.
Surface remelting,surface alloying and surface cladding are 3 essential processes in the surface modification of aluminium alloy by laser.They are distinctive,but there are some relations each other too.Through testing their microstructures and hardening effects are investigated and contrasted.The study can give guidance for the research and application of surface laser strengthening processes of aluminium alloy.
1997, 21(2): 92-95.
Abstract:
Based on the analysis of operating principles of magnetic-spiker-sustainer excitation used in excimer laser,this paper points out the technique is suitable to provide the laser pulses with the high efficiency,high average power and long duration.Experiment results show that the using the technique can generate the 170ns KrF laser pulses and 1μm XeCl laser pulses.
Based on the analysis of operating principles of magnetic-spiker-sustainer excitation used in excimer laser,this paper points out the technique is suitable to provide the laser pulses with the high efficiency,high average power and long duration.Experiment results show that the using the technique can generate the 170ns KrF laser pulses and 1μm XeCl laser pulses.
1997, 21(2): 96-100.
Abstract:
The dispersion compensation systems with a pair of double prisms or a group of four prisms used in self mode-locked Ti:2O3 lasers are theoretically studied in detail.The accurate expressions of second order and third order dispersion.The compensation results provided by the systems consisting of different optical materials are experimentally investigated.
The dispersion compensation systems with a pair of double prisms or a group of four prisms used in self mode-locked Ti:2O3 lasers are theoretically studied in detail.The accurate expressions of second order and third order dispersion.The compensation results provided by the systems consisting of different optical materials are experimentally investigated.
1997, 21(2): 101-103.
Abstract:
In this paper,experimental results of longitudinally-pumped Cr4+:Mg2SiO4 laser are reported.An output of 135mJ have been obtained by using 1.064μm Nd:YAG pulsed laser pump at room temperature.
In this paper,experimental results of longitudinally-pumped Cr4+:Mg2SiO4 laser are reported.An output of 135mJ have been obtained by using 1.064μm Nd:YAG pulsed laser pump at room temperature.
1997, 21(2): 104-106.
Abstract:
In this paper,the design of an auto-tuning Ti-saphire laser is described.The pumping source is a double frequency Nd:YAG laser,the maximum output energy of 60mJ per pulse with 37.5% conversion efficiency has been obtained at the repetition rate of 10Hz.
In this paper,the design of an auto-tuning Ti-saphire laser is described.The pumping source is a double frequency Nd:YAG laser,the maximum output energy of 60mJ per pulse with 37.5% conversion efficiency has been obtained at the repetition rate of 10Hz.
1997, 21(2): 106-108.
Abstract:
According to the characteristics of fuel spray,CBP(Convolution back projection),ART (Algebraic reconstruction technique) and SIRT (Simultaneous iterative reconstruction technique) were studied on the image reconstruction of fuel spray.The reconstruction results of the phantom using P540 digital image processing system showed that when there is noise in the projection data,the best image was reconstructed by SIRT whose calculation time was longest,the worst image was reconstructed by CBP whose calculation time was shortest,and ART is between them.
According to the characteristics of fuel spray,CBP(Convolution back projection),ART (Algebraic reconstruction technique) and SIRT (Simultaneous iterative reconstruction technique) were studied on the image reconstruction of fuel spray.The reconstruction results of the phantom using P540 digital image processing system showed that when there is noise in the projection data,the best image was reconstructed by SIRT whose calculation time was longest,the worst image was reconstructed by CBP whose calculation time was shortest,and ART is between them.
1997, 21(2): 111-114.
Abstract:
The laser longitudinal mode-split technology provides a powerful tool to study the power tuning property for a laser with various frequency spacing form a few tens of megahertz to half of the longitudinal mode spacing.A serious of experiments have been done.The experimental results show that the power varying trend of o-light and e-light are opposite to each other,no matter what kind of Ne(Ne20 or the mixture of Ne20 and Ne22) is used and how much the mode split is.
The laser longitudinal mode-split technology provides a powerful tool to study the power tuning property for a laser with various frequency spacing form a few tens of megahertz to half of the longitudinal mode spacing.A serious of experiments have been done.The experimental results show that the power varying trend of o-light and e-light are opposite to each other,no matter what kind of Ne(Ne20 or the mixture of Ne20 and Ne22) is used and how much the mode split is.
1997, 21(2): 115-119.
Abstract:
The paper analyzed the energy and signal noise ratio (SNR) resulted from the measuring of laser wavelength with a grating.For the measurement of laser wavelength,it is needed to have proper laser energy and SNR.This paper presented the experimental data and taken photographs,and discussed the experimental results from the view point of the energy measurement.
The paper analyzed the energy and signal noise ratio (SNR) resulted from the measuring of laser wavelength with a grating.For the measurement of laser wavelength,it is needed to have proper laser energy and SNR.This paper presented the experimental data and taken photographs,and discussed the experimental results from the view point of the energy measurement.
1997, 21(2): 119-121.
Abstract:
By means of optical and CCD image processing technique,a system for detection of the axial and radial jitter of wheel rim is introduced in this paper.With the system,the image of the wheel and the pattern shaded by the wheel are imaged on CCD sensor.According to the variations of the image and the shaded pattern,the axial and radial jitter can be calculated out.This paper gives out the main constructure of the detection system.
By means of optical and CCD image processing technique,a system for detection of the axial and radial jitter of wheel rim is introduced in this paper.With the system,the image of the wheel and the pattern shaded by the wheel are imaged on CCD sensor.According to the variations of the image and the shaded pattern,the axial and radial jitter can be calculated out.This paper gives out the main constructure of the detection system.
1997, 21(2): 122-127.
Abstract:
According to the characteristics of fuel spray,CBP (Convolution backprojection),ART (Algebraic reconstruction technique) and SIRT (Simultaneous iterative reconstruction technique),which are used to realize the visualization of the internal structure of fuel spray,are studied in this paper.The reconstruction results with a P540 digital image processing system show that when the noise exists in the projection data,the SIRT provided the best image reconstruction taking the longest calculation time,the worst image reconstruction is obtained by CBP taking the shortest calculation time,and ART is in the middle.
According to the characteristics of fuel spray,CBP (Convolution backprojection),ART (Algebraic reconstruction technique) and SIRT (Simultaneous iterative reconstruction technique),which are used to realize the visualization of the internal structure of fuel spray,are studied in this paper.The reconstruction results with a P540 digital image processing system show that when the noise exists in the projection data,the SIRT provided the best image reconstruction taking the longest calculation time,the worst image reconstruction is obtained by CBP taking the shortest calculation time,and ART is in the middle.
1997, 21(2): 128-129.
Abstract:
This artical introduces the new optoelectronic instrument for detection.It utilizes the Fourier transform of laser beam to extract defect data from workpiece,and then curries out optical information processing under microcomputer control.Automatic detect and classificatin of precision parts are implemented.The instrument had been accredited.
This artical introduces the new optoelectronic instrument for detection.It utilizes the Fourier transform of laser beam to extract defect data from workpiece,and then curries out optical information processing under microcomputer control.Automatic detect and classificatin of precision parts are implemented.The instrument had been accredited.
