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RSS2004 Vol. 28, No. 1
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2004, 28(1): 1-4.
[Abstract]
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Abstract:
The grey cast iron was alloyed by light beam remelting the preplacing layer of Cr powder. The microstructure and phase of alloying layers were analyzed by SEM,EDS and X-ray diffraction. The ring-block wear test was use to evaluate the wear resistance of alloying layers. The results show that the wear resistance of Cr powder alloying layer is greatly higher than that of grey cast iron. The wear resistance is heightened with the increases of preplacing mass of Cr powder,and the wear mechanism changes from furrow and scratch to surface plastic deformation. The reason is that with the increases of preplacing mass of Cr powder,the eutectic matrix of α-(Fe,Cr) rich in Fe+Cr7C3 in alloying layer is replaced by the eutectic of α-(Fe,Cr) rich in Fe+Cr23C6,then replaced by α-(Fe,Cr) ferrite rich in Cr.
The grey cast iron was alloyed by light beam remelting the preplacing layer of Cr powder. The microstructure and phase of alloying layers were analyzed by SEM,EDS and X-ray diffraction. The ring-block wear test was use to evaluate the wear resistance of alloying layers. The results show that the wear resistance of Cr powder alloying layer is greatly higher than that of grey cast iron. The wear resistance is heightened with the increases of preplacing mass of Cr powder,and the wear mechanism changes from furrow and scratch to surface plastic deformation. The reason is that with the increases of preplacing mass of Cr powder,the eutectic matrix of α-(Fe,Cr) rich in Fe+Cr7C3 in alloying layer is replaced by the eutectic of α-(Fe,Cr) rich in Fe+Cr23C6,then replaced by α-(Fe,Cr) ferrite rich in Cr.
2004, 28(1): 5-11.
Abstract:
This paper has reviewed the development of nanoparticles synthesis by laser evaporation condensation including types of nanoparticles,processing parameters,properties of nanoparticles and basic theories of laser evaporation condensation.The current problems and the research areas in the future are also given.
This paper has reviewed the development of nanoparticles synthesis by laser evaporation condensation including types of nanoparticles,processing parameters,properties of nanoparticles and basic theories of laser evaporation condensation.The current problems and the research areas in the future are also given.
2004, 28(1): 12-15,19.
Abstract:
Based on rate and propagation equations,the output signal power and noise characteristics of double cladding erbium-ytterbium co-doped fiber amplifiers with a reflection are analyzed numerically. Due to the contributions of the reflector to reflect the un-absorbed pump power,pump light transmitted in the active fiber is increased and the output performances are improved.It is shown that the amplifiers with the reflector only using half-lengths of fiber have about the same high power output signal as those without reflectors,for forward pumping and backward pumping,noise figures are obtained less than 4dB.
Based on rate and propagation equations,the output signal power and noise characteristics of double cladding erbium-ytterbium co-doped fiber amplifiers with a reflection are analyzed numerically. Due to the contributions of the reflector to reflect the un-absorbed pump power,pump light transmitted in the active fiber is increased and the output performances are improved.It is shown that the amplifiers with the reflector only using half-lengths of fiber have about the same high power output signal as those without reflectors,for forward pumping and backward pumping,noise figures are obtained less than 4dB.
2004, 28(1): 16-19.
Abstract:
To solve the difficulty of high silicon steel welding on the hot rolled sheet pickling line,new joining technology composed of laser cutting,laser welding and laser heat treating by a 4kW YAG laser has been presented.After testing on Hi B steel,this paper has explored the effects of welding parameters on the joint mechanical properties,profile and microstructure,and then optimized technological parameters.The study has proved feasibility of the presented method which has succeeded in industrial on-line production testing.
To solve the difficulty of high silicon steel welding on the hot rolled sheet pickling line,new joining technology composed of laser cutting,laser welding and laser heat treating by a 4kW YAG laser has been presented.After testing on Hi B steel,this paper has explored the effects of welding parameters on the joint mechanical properties,profile and microstructure,and then optimized technological parameters.The study has proved feasibility of the presented method which has succeeded in industrial on-line production testing.
2004, 28(1): 20-22,32.
Abstract:
Planar laser-induced fluorescence (PLIF) technique is utilized to measure the images of hydroxyl radicals (OH) fluorescence and spontaneous emission in hydrogen/air and kerosene/air supersonic combustion. The results show that PLIF has been an efficient approach for identification of fuel/air mixing and combustion process. It is found that large number of OH radical is concentrated in the cavity range of the combustor, it is helpful to understand the mechanism of the cavity as the flame-holder in supersonic combustor.
Planar laser-induced fluorescence (PLIF) technique is utilized to measure the images of hydroxyl radicals (OH) fluorescence and spontaneous emission in hydrogen/air and kerosene/air supersonic combustion. The results show that PLIF has been an efficient approach for identification of fuel/air mixing and combustion process. It is found that large number of OH radical is concentrated in the cavity range of the combustor, it is helpful to understand the mechanism of the cavity as the flame-holder in supersonic combustor.
2004, 28(1): 23-25.
Abstract:
The cascaded acoustooptic interaction is usually used for the need of the devices'structure and function when the acoustooptic devices are designed and fabricated. The frequency shifting and beam deflection of the Bragg acoustooptic interaction in cascade is analyzed according to general Bragg acoustooptic interaction theory. Different frequency shifting and beam deflection can be obtained when the different cascaded acoustooptic interaction scheme is used. An important conclusion is presented that the doubly and frequency-shifted diffracted light propagates in a fixed direction irrespective of magnitude of frequency shift if the two acoustic wave frequency is changed rationally.
The cascaded acoustooptic interaction is usually used for the need of the devices'structure and function when the acoustooptic devices are designed and fabricated. The frequency shifting and beam deflection of the Bragg acoustooptic interaction in cascade is analyzed according to general Bragg acoustooptic interaction theory. Different frequency shifting and beam deflection can be obtained when the different cascaded acoustooptic interaction scheme is used. An important conclusion is presented that the doubly and frequency-shifted diffracted light propagates in a fixed direction irrespective of magnitude of frequency shift if the two acoustic wave frequency is changed rationally.
2004, 28(1): 26-28,35.
Abstract:
Ag metal layer is deposited on epoxy-resin board by means of CO2 laser-induced deposition in aqueous solution.Owing to activities of Ag crystallites, Cu layer can be deposited on Ag metal layer quickly. The micro-structure of metal layer is investigated by means of EPMA (electric probe micro-analysis) and DFM(dynamic force microscope). It is concluded that the influenced factors to adhesion of Cu layer are Ag layer surface morphology,Ag layer depth and surface roughness of epoxy-resin board.
Ag metal layer is deposited on epoxy-resin board by means of CO2 laser-induced deposition in aqueous solution.Owing to activities of Ag crystallites, Cu layer can be deposited on Ag metal layer quickly. The micro-structure of metal layer is investigated by means of EPMA (electric probe micro-analysis) and DFM(dynamic force microscope). It is concluded that the influenced factors to adhesion of Cu layer are Ag layer surface morphology,Ag layer depth and surface roughness of epoxy-resin board.
2004, 28(1): 29-32.
Abstract:
Thin gallium nitride films,grown on sapphire substrates by MOCVD,are debonded by laser-induced lift-off. 3μm thick GaN membranes and 5μm thick InGaN MQW LD membranes are successfully separated from the growth substrates using KrF pulsed-excimer laser.Characterization of laser lift-off technology between wafers with sapphire substrates backside polished and wafers with sapphire substrates backside unpolished are compared.The threshold intensities are about 200mJ/cm2 and 300mJ/cm2 for these two kinds of wafers,and incident pulse intensities of 400mJ/cm2 and 600mJ/cm2 were required for stable interface splitting respectively. The InGaN MQW LD films are transfired onto a Si or InP support substrate and then cleaved. SEM was employed to analyze the cleaved facet. It can be concluded that the cleaved facet is ideal. GaN-based opto-electronic and electronic devices without sapphire substrate are available with this technology.
Thin gallium nitride films,grown on sapphire substrates by MOCVD,are debonded by laser-induced lift-off. 3μm thick GaN membranes and 5μm thick InGaN MQW LD membranes are successfully separated from the growth substrates using KrF pulsed-excimer laser.Characterization of laser lift-off technology between wafers with sapphire substrates backside polished and wafers with sapphire substrates backside unpolished are compared.The threshold intensities are about 200mJ/cm2 and 300mJ/cm2 for these two kinds of wafers,and incident pulse intensities of 400mJ/cm2 and 600mJ/cm2 were required for stable interface splitting respectively. The InGaN MQW LD films are transfired onto a Si or InP support substrate and then cleaved. SEM was employed to analyze the cleaved facet. It can be concluded that the cleaved facet is ideal. GaN-based opto-electronic and electronic devices without sapphire substrate are available with this technology.
2004, 28(1): 33-35.
Abstract:
The self-mixing interference of orthogonal polarized lights coming from a frequency splitting He-Ne laser is experimentally studied. Owing to mode competitive effects between orthogonal polarized o-light and e-light,maximum of the o-light is corresponding to minimum of the e-light in the feedback curve of the o-light and e-light,or vice versa. In a period,the maximum appears two times when the maximum of the general feedback curve appears one time,and the amplitude also changes two times.
The self-mixing interference of orthogonal polarized lights coming from a frequency splitting He-Ne laser is experimentally studied. Owing to mode competitive effects between orthogonal polarized o-light and e-light,maximum of the o-light is corresponding to minimum of the e-light in the feedback curve of the o-light and e-light,or vice versa. In a period,the maximum appears two times when the maximum of the general feedback curve appears one time,and the amplitude also changes two times.
2004, 28(1): 36-38,41.
Abstract:
With ray tracing method,a calculating model of laser diode directly side-pumping method is proposed,and the gain distribution characteristics in the active medium side-pumped by diode bars are studied.The effects of system parameters change on the homogeneity are analyzed.The fluorescence distributions of the active medium are tested with CCD for three different side-pumped construction.The experimental results agree well with the results of the calculation of this model.This model can completely be put into practice.
With ray tracing method,a calculating model of laser diode directly side-pumping method is proposed,and the gain distribution characteristics in the active medium side-pumped by diode bars are studied.The effects of system parameters change on the homogeneity are analyzed.The fluorescence distributions of the active medium are tested with CCD for three different side-pumped construction.The experimental results agree well with the results of the calculation of this model.This model can completely be put into practice.
2004, 28(1): 39-41.
Abstract:
According to a lot of experimental research to Cr,Tm,Ho:YAG laser operating at 2.1μm wavelength,the factors effecting on the output characteristics,such as cavity length,transparent index of output mirror,the radius of high reflectivity concave mirror and cooling temperatures,are discussed.Using the cavity with silver,whose frequency is 5Hz,the laser threshold,slope efficiency and output maximum energy are 47J,1.3% and 1.6J respectively. Meanwhile,when whose frequency is 10Hz,the laser threshold,slope efficiency and output maximum energy are 45J,1.1% and 0.97J respectively.
According to a lot of experimental research to Cr,Tm,Ho:YAG laser operating at 2.1μm wavelength,the factors effecting on the output characteristics,such as cavity length,transparent index of output mirror,the radius of high reflectivity concave mirror and cooling temperatures,are discussed.Using the cavity with silver,whose frequency is 5Hz,the laser threshold,slope efficiency and output maximum energy are 47J,1.3% and 1.6J respectively. Meanwhile,when whose frequency is 10Hz,the laser threshold,slope efficiency and output maximum energy are 45J,1.1% and 0.97J respectively.
2004, 28(1): 42-44.
Abstract:
The effects of He-Ne laser pretreatment on the seed of isatis indigotica have been studied in the following aspects,such as content of photoproducts and chlorophyll,biomass,net photosynthetic rate,stomatal conductance and water use efficiency.The results indicated four treatments have improved apparently the content of photoproducts and chlorophyll,stomatal conductance,water use efficiency,level of net photosynthetic rate and so on.Compared with the control,5min treatment is the best among four treatments.Moreover,the influence mechanism of laser irradiation on seedling photosynthesis has been discussed on the basis of the above results.
The effects of He-Ne laser pretreatment on the seed of isatis indigotica have been studied in the following aspects,such as content of photoproducts and chlorophyll,biomass,net photosynthetic rate,stomatal conductance and water use efficiency.The results indicated four treatments have improved apparently the content of photoproducts and chlorophyll,stomatal conductance,water use efficiency,level of net photosynthetic rate and so on.Compared with the control,5min treatment is the best among four treatments.Moreover,the influence mechanism of laser irradiation on seedling photosynthesis has been discussed on the basis of the above results.
2004, 28(1): 45-47.
Abstract:
Based on the principle of "freezing" high-velocity particles,an in-line Fraunhofer far-field holography measurment system,which uses the ultra-short pulse laser as the recording light source,is constructed.The metal micro-jet is loaded by detonation.The hologram of micro-jet is obtained by this system.By reconstructing the hologram,the distribution and the size of the micro jet can be analyzed.
Based on the principle of "freezing" high-velocity particles,an in-line Fraunhofer far-field holography measurment system,which uses the ultra-short pulse laser as the recording light source,is constructed.The metal micro-jet is loaded by detonation.The hologram of micro-jet is obtained by this system.By reconstructing the hologram,the distribution and the size of the micro jet can be analyzed.
2004, 28(1): 48-51.
Abstract:
Photonic crystal fiber(PCF) has more excellent properties than common fiber,such as single mode,dispersion and nonlinearity. The basic structures and virtues of photonic crystal fiber are studied in this article,then the development of photonic crystal fiber laser,and high power fiber laser with PCFs is presented.
Photonic crystal fiber(PCF) has more excellent properties than common fiber,such as single mode,dispersion and nonlinearity. The basic structures and virtues of photonic crystal fiber are studied in this article,then the development of photonic crystal fiber laser,and high power fiber laser with PCFs is presented.
2004, 28(1): 52-54.
Abstract:
The solid dye samples used in our experiment is made by a stepwise synthesis technique through a sol gel process.Laser dye doped in the sample is pyrromethene 567.Longitudinally pumped tunable solid state dye lasers with intra cavity grating are established with Q-switched frequency doubled Nd:YAG laser pumping source.The slope efficiency of 9.7% and tunable range over 30nm(from 553nm～585nm) has been achieved.The pulse width is 4ns and the spectrum width is 0.014nm at 574nm wavelength.The laser output broad band of 7nm(FWHM) and 69% slope efficiency are also obtained in the experiment.With 0.1J/cm2 pump fluency and 2Hz repetition rate,the output energy decreases to 50% of initial value after 38000 shots.
The solid dye samples used in our experiment is made by a stepwise synthesis technique through a sol gel process.Laser dye doped in the sample is pyrromethene 567.Longitudinally pumped tunable solid state dye lasers with intra cavity grating are established with Q-switched frequency doubled Nd:YAG laser pumping source.The slope efficiency of 9.7% and tunable range over 30nm(from 553nm～585nm) has been achieved.The pulse width is 4ns and the spectrum width is 0.014nm at 574nm wavelength.The laser output broad band of 7nm(FWHM) and 69% slope efficiency are also obtained in the experiment.With 0.1J/cm2 pump fluency and 2Hz repetition rate,the output energy decreases to 50% of initial value after 38000 shots.
2004, 28(1): 55-57.
Abstract:
The laser confocal scanning microscopic (LCSM) system is one kind of modern microscopic instruments which are characterized by depth discrimination capability. However,in order to obtain the three-dimensional images of an object,the three-dimension reconstruction is very importment. In this paper,the theories and methods of how to create accurate depictions of three-dimension data on the screen of a computer device is discussed and a new three-dimension reconstruction method based on surface is proprosed.The experiment results show that the reconstructed images have high quality.
The laser confocal scanning microscopic (LCSM) system is one kind of modern microscopic instruments which are characterized by depth discrimination capability. However,in order to obtain the three-dimensional images of an object,the three-dimension reconstruction is very importment. In this paper,the theories and methods of how to create accurate depictions of three-dimension data on the screen of a computer device is discussed and a new three-dimension reconstruction method based on surface is proprosed.The experiment results show that the reconstructed images have high quality.
2004, 28(1): 58-60,64.
Abstract:
The recursion expression applicable to a quarter-wave (QW) multi-layer dielectric film stack with weak absorptions has been used to study the reflection characteristics of mirrors. A weighting factor has been introduced to quantify the contributions of each constituent layer to such mirror characteristics as the reflection delay,reflectivity reduction,etc. For convenience,the weighting factor has been expressed in terms of the refractive indices of the individual layers of the mirror,based on which the reflection delay and reflectivity reduction have been discussed thereafter.
The recursion expression applicable to a quarter-wave (QW) multi-layer dielectric film stack with weak absorptions has been used to study the reflection characteristics of mirrors. A weighting factor has been introduced to quantify the contributions of each constituent layer to such mirror characteristics as the reflection delay,reflectivity reduction,etc. For convenience,the weighting factor has been expressed in terms of the refractive indices of the individual layers of the mirror,based on which the reflection delay and reflectivity reduction have been discussed thereafter.
2004, 28(1): 61-64.
Abstract:
A flexible and simple method for UV writing of Bragg gratings and polarization control method,is presented.The method is based on a phase shift between the refractive-index modulation profiles induced by s and p polarization of UV light.The modulation strength is able to be controlled and phase shifts are induced by changing the ratio of UV intensity in the two polarizations.Characteristics of spectrum of two written gratings are analysed,in good agreement with theoretical predictions.
A flexible and simple method for UV writing of Bragg gratings and polarization control method,is presented.The method is based on a phase shift between the refractive-index modulation profiles induced by s and p polarization of UV light.The modulation strength is able to be controlled and phase shifts are induced by changing the ratio of UV intensity in the two polarizations.Characteristics of spectrum of two written gratings are analysed,in good agreement with theoretical predictions.
2004, 28(1): 65-67,73.
Abstract:
Based on the equivalent resonator method,the results of a two rod plane-plane resonator used for high power solid state lasers are extended to multirod plane-plane resonators.The analytical expressions for g*-parameters and equivalent resonator length of a multirod plane-plane resonator are derived.The dynamic characteristics of such a type of resonator are analyzed in detail,and illustrated with numerical examples.It is shown that for two types of multirod symmetric plane-plane resonators,the characteristic curve on the g*-parameter diagram is a straight line passing through the origin.If there is a small discrepance of the thermal focal length of rods,the characteristic curve is no longer a straight line.However,by a suitable adjustment of the distances between the mirrors and rods,the curve becomes again a straight line.Therefore,the discrepance of the thermal focal length can be compensated in such a way,and the relevant mathematical formula is also proposed.
Based on the equivalent resonator method,the results of a two rod plane-plane resonator used for high power solid state lasers are extended to multirod plane-plane resonators.The analytical expressions for g*-parameters and equivalent resonator length of a multirod plane-plane resonator are derived.The dynamic characteristics of such a type of resonator are analyzed in detail,and illustrated with numerical examples.It is shown that for two types of multirod symmetric plane-plane resonators,the characteristic curve on the g*-parameter diagram is a straight line passing through the origin.If there is a small discrepance of the thermal focal length of rods,the characteristic curve is no longer a straight line.However,by a suitable adjustment of the distances between the mirrors and rods,the curve becomes again a straight line.Therefore,the discrepance of the thermal focal length can be compensated in such a way,and the relevant mathematical formula is also proposed.
2004, 28(1): 68-73.
Abstract:
Organic white-light emitting devices(OWLEDs) have tremendous application merits and potential markets.There are mostly two kinds of OWLEDs,one based on electroluminescence(EL),the other on photoluminescence (PL).The main principles of EL are multiple quantum well,exciplex and energy transfer.The organic EL devices have been more investigated and there are products in near future.But for organic PL devices,there are less study.The cost of PL OWLEDs is lower than that of EL OWLEDs,and its fluorescence efficiency may be higher.Therefore OWLEDs stand for a cheap route for luminescent technique.A summary of OWLEDs mechanisms and development are put forward.
Organic white-light emitting devices(OWLEDs) have tremendous application merits and potential markets.There are mostly two kinds of OWLEDs,one based on electroluminescence(EL),the other on photoluminescence (PL).The main principles of EL are multiple quantum well,exciplex and energy transfer.The organic EL devices have been more investigated and there are products in near future.But for organic PL devices,there are less study.The cost of PL OWLEDs is lower than that of EL OWLEDs,and its fluorescence efficiency may be higher.Therefore OWLEDs stand for a cheap route for luminescent technique.A summary of OWLEDs mechanisms and development are put forward.
2004, 28(1): 74-77.
Abstract:
Hydroxyapatite (HA) have been used as coatings on implants for orthopedics,neurosurgery and dentistry owing to their biocompatible properties. Recently,pulsed laser deposition (PLD) was investigated to produce HA films of high crystallinity and bonding strength. The purpose of this paper is to summarize the present situation of HA films deposited by pulsed laser and systematically review the effect of various parameters of the PLD process on the properties of films,including target properties,ambient gas,substrate temperature,buffer layer,laser wavelength and energy density. Mechanical properties and bioactivity were analyzed,and the application foreground was also prospected.
Hydroxyapatite (HA) have been used as coatings on implants for orthopedics,neurosurgery and dentistry owing to their biocompatible properties. Recently,pulsed laser deposition (PLD) was investigated to produce HA films of high crystallinity and bonding strength. The purpose of this paper is to summarize the present situation of HA films deposited by pulsed laser and systematically review the effect of various parameters of the PLD process on the properties of films,including target properties,ambient gas,substrate temperature,buffer layer,laser wavelength and energy density. Mechanical properties and bioactivity were analyzed,and the application foreground was also prospected.
2004, 28(1): 78-81.
Abstract:
This paper proposes the face recognition method based on principle component analysis (PCA) and independent component analysis (ICA). PCA and ICA are both multivariable data statistics.In order to reduce dimension and sec order correlation,firstly,the image data can be processed by PCA,and then the independent image basis can be got using ICA,finally,face recognition is processed in the subspace. In our experiments,the proposed methods have been successfully evaluated using two different datasets,and PCA and ICA method are compared.The experimental results show that ICA face recognition method is superior to PCA method.
This paper proposes the face recognition method based on principle component analysis (PCA) and independent component analysis (ICA). PCA and ICA are both multivariable data statistics.In order to reduce dimension and sec order correlation,firstly,the image data can be processed by PCA,and then the independent image basis can be got using ICA,finally,face recognition is processed in the subspace. In our experiments,the proposed methods have been successfully evaluated using two different datasets,and PCA and ICA method are compared.The experimental results show that ICA face recognition method is superior to PCA method.
2004, 28(1): 82-84,87.
Abstract:
The range-finding capability is one of the major performance of the laser range finder.A new checking method of the range-finding capability,extinction ratio measurement without target,by which laser emission capability and reception capability can be dividually measured,is put forward.Based on which,a new tester for the range-finding capability of laser range finders is developed. No targets are necessary.It is no more restricted to environment nearby,and an accurate result can be acquired rapidly.It proved to be instructional for maintenance.
The range-finding capability is one of the major performance of the laser range finder.A new checking method of the range-finding capability,extinction ratio measurement without target,by which laser emission capability and reception capability can be dividually measured,is put forward.Based on which,a new tester for the range-finding capability of laser range finders is developed. No targets are necessary.It is no more restricted to environment nearby,and an accurate result can be acquired rapidly.It proved to be instructional for maintenance.
2004, 28(1): 85-87.
Abstract:
KrF excimer laser, whose wavelength is 248nm, is directly used to ablate and etch glass material;the location of processed material is accurately controlled by a micro motion controlling system. The relationships between laser pulse parameters, the number and energy and characteristics of yielded grooves are investigated. It is shown that the ablation depth of a single laser pulse becomes smaller and smaller along with the increasing of laser pulse amount. Furthermore, the depth of the yielded grooves becomes constant when the laser pulses add up to a definite number. The more the energy of laser pulse the more the etching speed is. There is an upper limit for the etching speed.
KrF excimer laser, whose wavelength is 248nm, is directly used to ablate and etch glass material;the location of processed material is accurately controlled by a micro motion controlling system. The relationships between laser pulse parameters, the number and energy and characteristics of yielded grooves are investigated. It is shown that the ablation depth of a single laser pulse becomes smaller and smaller along with the increasing of laser pulse amount. Furthermore, the depth of the yielded grooves becomes constant when the laser pulses add up to a definite number. The more the energy of laser pulse the more the etching speed is. There is an upper limit for the etching speed.
2004, 28(1): 88-90.
Abstract:
The interaction between two dark solitons of nonlinear Schrodinger equation is derived with the variational principle approach. The interaction as a function of the soliton's separation Δ and their initial relative phase θ shows that the interaction decreased exponentially as Δ raise, and that two solitons repulse with each other when θπ/2.Analysis conforms to numerical calculation and it has also proved the validity of the existed theory.
The interaction between two dark solitons of nonlinear Schrodinger equation is derived with the variational principle approach. The interaction as a function of the soliton's separation Δ and their initial relative phase θ shows that the interaction decreased exponentially as Δ raise, and that two solitons repulse with each other when θπ/2.Analysis conforms to numerical calculation and it has also proved the validity of the existed theory.
2004, 28(1): 91-93.
Abstract:
Considering the specific requirement of reliability of military lasers, a consolidated intracavity eye safe optical parametric oscillator (OPO) is designed. By using double directional prism resonator,Cr4+:YAG passive Q-switch, Ce Nd:YAG laser rod, noncritical phase matching KTP crystal,1.57μm OPO laser is obtained with 5.3mJ/pulse of energy,≈6 ns of pulse width and ≈5mrad of divergence. After continuously working for 1min at the repetition rate of 3Hz, the output energy and optical axis is still stable. It had the characteristics of compact structure and high reliability.
Considering the specific requirement of reliability of military lasers, a consolidated intracavity eye safe optical parametric oscillator (OPO) is designed. By using double directional prism resonator,Cr4+:YAG passive Q-switch, Ce Nd:YAG laser rod, noncritical phase matching KTP crystal,1.57μm OPO laser is obtained with 5.3mJ/pulse of energy,≈6 ns of pulse width and ≈5mrad of divergence. After continuously working for 1min at the repetition rate of 3Hz, the output energy and optical axis is still stable. It had the characteristics of compact structure and high reliability.
2004, 28(1): 94-97,102.
Abstract:
Influence of position of output mirror on beam of two-rod solid-state laser has been analysed by means of matrix optics and experiment. The results show that the stability zone,the mode volume and the output power of two-rod solid state laser are affected by the position of output mirror. The mode volume and output power of equal interval resontor are larger than the other resontors.The facula radius w0 and the far field divergent angle θ0 are also affected by the position of the output mirror.The optimum transmissivity of output mirror for two-rod solid state laser has been investigated by experiment.
Influence of position of output mirror on beam of two-rod solid-state laser has been analysed by means of matrix optics and experiment. The results show that the stability zone,the mode volume and the output power of two-rod solid state laser are affected by the position of output mirror. The mode volume and output power of equal interval resontor are larger than the other resontors.The facula radius w0 and the far field divergent angle θ0 are also affected by the position of the output mirror.The optimum transmissivity of output mirror for two-rod solid state laser has been investigated by experiment.
2004, 28(1): 98-102.
Abstract:
At first,this paper introduced the basic requirements,classification and specification of laser warning receivers briefly.The structure and specification of laser warning receivers being in use or developed were then summarized in detail. The future of laser warning receivers was finally forecasted.
At first,this paper introduced the basic requirements,classification and specification of laser warning receivers briefly.The structure and specification of laser warning receivers being in use or developed were then summarized in detail. The future of laser warning receivers was finally forecasted.
2004, 28(1): 103-107.
Abstract:
The present application and study situation of laser-induced breakdown spectroscopy(LIBS) are reviewed. The principle,characters,history and recent trend of LIBS are introduced systematically.Theoretically,some equilibrium and non equilibrium problems in laser-induced plasma are studied deeply. In addition,the LIBS technology has widely applied in some fields,such as combustion,metallurgy,water and soil pollution,artwork authenticate,polymer identification and so on.Furthermore,there are some instruments coming into the market.
The present application and study situation of laser-induced breakdown spectroscopy(LIBS) are reviewed. The principle,characters,history and recent trend of LIBS are introduced systematically.Theoretically,some equilibrium and non equilibrium problems in laser-induced plasma are studied deeply. In addition,the LIBS technology has widely applied in some fields,such as combustion,metallurgy,water and soil pollution,artwork authenticate,polymer identification and so on.Furthermore,there are some instruments coming into the market.
2004, 28(1): 108-110.
Abstract:
There are two different approaches to deal with focal shifts,i.e.,Li-Wolf's and Greene Hall's approaches.In this paper focal shifts in elegant(complex-argument)Laguerre-Gaussian(ELG)beams are taken as a typical example,a detailed comparative study of the two approaches is made and numerical calculations results are illustr ated.The conclusion made in this paper is useful for some practical applications.
There are two different approaches to deal with focal shifts,i.e.,Li-Wolf's and Greene Hall's approaches.In this paper focal shifts in elegant(complex-argument)Laguerre-Gaussian(ELG)beams are taken as a typical example,a detailed comparative study of the two approaches is made and numerical calculations results are illustr ated.The conclusion made in this paper is useful for some practical applications.
2004, 28(1): 111-112.
Abstract:
This paper makes a conclusion that there's equivalent fast axis in three-in-one composition wave-plate,and there's no equivalent fast axis in two-in-one composition wave-plate but have a special angle which can be taken for equivalent fast axis.
This paper makes a conclusion that there's equivalent fast axis in three-in-one composition wave-plate,and there's no equivalent fast axis in two-in-one composition wave-plate but have a special angle which can be taken for equivalent fast axis.
