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RSS1998 Vol. 22, No. 6
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1998, 22(6): 321-324.
[Abstract]
[PDF 772KB]
Abstract:
A new kind of edge lit circular viewing rainbow hologram is presented in this paper,which uses a wave guided grating as illuminator.It has advantages of both wave guided hologram and circular viewing rainbow holograms and make the reconstruction structure more compact.It can be viewed very conveniently and flexibility.
A new kind of edge lit circular viewing rainbow hologram is presented in this paper,which uses a wave guided grating as illuminator.It has advantages of both wave guided hologram and circular viewing rainbow holograms and make the reconstruction structure more compact.It can be viewed very conveniently and flexibility.
1998, 22(6): 325-328.
Abstract:
A real industry scale frequency stabilized system for transverse Zeeman laser tube is composed.It is based on 8098 single chip computer system,which calculates control voltage with MPC algorithm and outputs PWM wave to realize thermal compensation.Because the control voltage calculated from MPC algorithm is always real number,it must be rounded to integer.This round error can influence the control performance seriously.A method of improving D/A converting precision by modulating pulse width of PWM wave with low frequency and little amplitude is introduced.The experiment show that it is effctive.By adopting this method,control range is enlarged,so that the system can be stabilized over longer period than 10h.The laser tube reached frequency stability of 8.7×10-10 with sample time period of 10s.
A real industry scale frequency stabilized system for transverse Zeeman laser tube is composed.It is based on 8098 single chip computer system,which calculates control voltage with MPC algorithm and outputs PWM wave to realize thermal compensation.Because the control voltage calculated from MPC algorithm is always real number,it must be rounded to integer.This round error can influence the control performance seriously.A method of improving D/A converting precision by modulating pulse width of PWM wave with low frequency and little amplitude is introduced.The experiment show that it is effctive.By adopting this method,control range is enlarged,so that the system can be stabilized over longer period than 10h.The laser tube reached frequency stability of 8.7×10-10 with sample time period of 10s.
1998, 22(6): 328-332.
Abstract:
A second harmonic generation (SHG) measurement system for organic powders have been built.Then the second order nonlinear optical properties of acridine derivates have been measured with this experimental setup and compared with the calculated value obtained by the solvatochromic method.The intensity of second harmonic generation of acridine derivate microcrystal was related to its structure and molecular refractive index.Acridines with two dimension dipole "Λ" type structure,intermolecular hydrogen bond,long chain alkyl with branches and methyl group possess high nonlinear optical properties.The relative SHG of these microcrystals were proportional to their hypersusceptibilities,but not comformed to the Kurtz Perry relation.
A second harmonic generation (SHG) measurement system for organic powders have been built.Then the second order nonlinear optical properties of acridine derivates have been measured with this experimental setup and compared with the calculated value obtained by the solvatochromic method.The intensity of second harmonic generation of acridine derivate microcrystal was related to its structure and molecular refractive index.Acridines with two dimension dipole "Λ" type structure,intermolecular hydrogen bond,long chain alkyl with branches and methyl group possess high nonlinear optical properties.The relative SHG of these microcrystals were proportional to their hypersusceptibilities,but not comformed to the Kurtz Perry relation.
1998, 22(6): 333-335.
Abstract:
In this experimental research,it is introduced that a 5kW CO2 laser with transverse flow for cladding Ni base alloy coat on austenite basic of the sealing surface of medium and high pressure valve for petrochemical industry.After processed by the laser cladding,the laser cladding coat of 3mm thick can be mede with a smooth surface.The test and comparison analysis indicated that the microstructure and all the performance have obvious advantages over the spurt welding processing.
In this experimental research,it is introduced that a 5kW CO2 laser with transverse flow for cladding Ni base alloy coat on austenite basic of the sealing surface of medium and high pressure valve for petrochemical industry.After processed by the laser cladding,the laser cladding coat of 3mm thick can be mede with a smooth surface.The test and comparison analysis indicated that the microstructure and all the performance have obvious advantages over the spurt welding processing.
1998, 22(6): 336-339.
Abstract:
This paper reported the design of a polarizer,which is used in detection of the optical constant of metal materials.The polarizer is composed of three reflective mirrors set at Brewster's angle.This polarized laser beam is employed experimentally to detect the reflective properties or optical constants of metal surface at different incident angles.
This paper reported the design of a polarizer,which is used in detection of the optical constant of metal materials.The polarizer is composed of three reflective mirrors set at Brewster's angle.This polarized laser beam is employed experimentally to detect the reflective properties or optical constants of metal surface at different incident angles.
1998, 22(6): 339-342.
Abstract:
In this paper the application of optical coherence tomography in different fields was introduced and the possible future developments are presented.
In this paper the application of optical coherence tomography in different fields was introduced and the possible future developments are presented.
1998, 22(6): 343-345.
Abstract:
Effects of laser cutting factors on cutting quality of low carbon steel sheets are studied in this paper.The optimal technological parameters of laser cutting are obtained.The problems and solutions are analysed and discussed.
Effects of laser cutting factors on cutting quality of low carbon steel sheets are studied in this paper.The optimal technological parameters of laser cutting are obtained.The problems and solutions are analysed and discussed.
1998, 22(6): 346-349.
Abstract:
The optical scanning mirror is a key component in laser scanning detection system.The purpose of the paper is to introduce the theoretical analysis,parameter selection and design method of the rotatory polyhedron scanning system.The fundamental requirements to construct a rotatory polyhedron scanning system are much high geometry or manufacture accuracy,very small rotatiry deformation of the rotation components.Finally,this paper discussed the scanning effectiveness,and point out that the selection of scanning effectiveness is in the range of 0.4～0.6,and how to select other relative parameters.
The optical scanning mirror is a key component in laser scanning detection system.The purpose of the paper is to introduce the theoretical analysis,parameter selection and design method of the rotatory polyhedron scanning system.The fundamental requirements to construct a rotatory polyhedron scanning system are much high geometry or manufacture accuracy,very small rotatiry deformation of the rotation components.Finally,this paper discussed the scanning effectiveness,and point out that the selection of scanning effectiveness is in the range of 0.4～0.6,and how to select other relative parameters.
1998, 22(6): 350-352.
Abstract:
A method to measure solid linear expension coefficient is presented,using laser deflection method and CCD device.In this paper,the block diagram of system structure,computer program and procision analysis are given.In contrast to conventional measuring technique,the subjective error is eliminated,the objectivity of the result is better.
A method to measure solid linear expension coefficient is presented,using laser deflection method and CCD device.In this paper,the block diagram of system structure,computer program and procision analysis are given.In contrast to conventional measuring technique,the subjective error is eliminated,the objectivity of the result is better.
1998, 22(6): 352-356.
Abstract:
The 3D laser cutting has widely been applied in automotive industry and aerospace industry.This paper summarizes the development of 3D laser cutting machine,illustrates the applications and problems of 3D laser cutting.
The 3D laser cutting has widely been applied in automotive industry and aerospace industry.This paper summarizes the development of 3D laser cutting machine,illustrates the applications and problems of 3D laser cutting.
1998, 22(6): 357-361.
Abstract:
Estimation of output power for high output power single frequency He-Ne laser of self-stabilized frequency is introduced.The theory estimation results of output power much approximate to measurement data.Two series of single and self-stabilization frequency high output power external cavity He-Ne laser are obtained with inhomogeneous longitudinal magnetic fields and high gas pressure.With the discharge tube of one meter (cavity length 1140mm) and 1.8 meters length (cavity length 1800mm) the output power are 18～24mW and 40～52mW respectively.The coherence length of these lasers exceeds 14 meters.Whithout any external frequency stabilization method the instability of the single frequency are 6.175×10-9 (τ≤10s),3.38×10-9 (τ≤1s) for one meter laser,and 2×10-8 (τ≤10s),1.1×10-8 (τ≤1s) for 1.8 meters by multi measurements of the beat frequency between the single He-Ne laser and an iodine stabilized He-Ne laser.
Estimation of output power for high output power single frequency He-Ne laser of self-stabilized frequency is introduced.The theory estimation results of output power much approximate to measurement data.Two series of single and self-stabilization frequency high output power external cavity He-Ne laser are obtained with inhomogeneous longitudinal magnetic fields and high gas pressure.With the discharge tube of one meter (cavity length 1140mm) and 1.8 meters length (cavity length 1800mm) the output power are 18～24mW and 40～52mW respectively.The coherence length of these lasers exceeds 14 meters.Whithout any external frequency stabilization method the instability of the single frequency are 6.175×10-9 (τ≤10s),3.38×10-9 (τ≤1s) for one meter laser,and 2×10-8 (τ≤10s),1.1×10-8 (τ≤1s) for 1.8 meters by multi measurements of the beat frequency between the single He-Ne laser and an iodine stabilized He-Ne laser.
1998, 22(6): 361-366.
Abstract:
This paper gives a brief introduction of the situation of researches on photorefractive phase conjugation techniques,pays particular attention to introduce the progress of the researches on self pumped phase conjugator and mutually pumped phase conjugator, and explains thier structures and mechanisms.
This paper gives a brief introduction of the situation of researches on photorefractive phase conjugation techniques,pays particular attention to introduce the progress of the researches on self pumped phase conjugator and mutually pumped phase conjugator, and explains thier structures and mechanisms.
1998, 22(6): 367-371.
Abstract:
Using the coupled mode theory,we study the reflection properties of the fiber grating with a reasonable assumption of the refraction index distribution.Relationships between the reflection properties and relevant fiber parameters are discussed.The basis of theory to fabricuting fiber gratings are deduced with phase masks,and some valuable conclusions and formulas are obtained.
Using the coupled mode theory,we study the reflection properties of the fiber grating with a reasonable assumption of the refraction index distribution.Relationships between the reflection properties and relevant fiber parameters are discussed.The basis of theory to fabricuting fiber gratings are deduced with phase masks,and some valuable conclusions and formulas are obtained.
1998, 22(6): 371-375.
Abstract:
Using general expression of output spectrum from end reflector of a two segment semiconductor laser,deduced from ray trace method,the study on the characteristics of the two electrode diode lasers (TELDs) and external cavity diode laser has been carried out.
Using general expression of output spectrum from end reflector of a two segment semiconductor laser,deduced from ray trace method,the study on the characteristics of the two electrode diode lasers (TELDs) and external cavity diode laser has been carried out.
1998, 22(6): 376-378.
Abstract:
The double telescopic resonator constructed by a inverse telescope set in the side of the objective lens of an ordinary telescope resonator has been studied.The experimental results show that the cavity has not only better mode selection characteristics,but also higher ability of anti-beam-damage.
The double telescopic resonator constructed by a inverse telescope set in the side of the objective lens of an ordinary telescope resonator has been studied.The experimental results show that the cavity has not only better mode selection characteristics,but also higher ability of anti-beam-damage.
1998, 22(6): 379-382.
Abstract:
In the paper,the experimental setup and even boundary condition on thermal dark spatial optical solitons was designed,and the experiment was realized in BR.Finally,numerical results of thermal dark solitons were simulated by the split step Fourier method,and the results were same as of the experiment.
In the paper,the experimental setup and even boundary condition on thermal dark spatial optical solitons was designed,and the experiment was realized in BR.Finally,numerical results of thermal dark solitons were simulated by the split step Fourier method,and the results were same as of the experiment.
1998, 22(6): 382-386.
Abstract:
Thermal and mechanical response,stress statute,deformation and damage of pre-pulled,pre-pressed and pre twisted LY12 aluminum alloy specimens caused by irradiation of high-power CW CO2 laser beam were studied in this paper.The parameters of laser irradiation and the microstructure of laser irradiated area were analyzed for different types of pre loading and different shapes of specimens. Under the combined laser beam irradiation and mechnical pre-loading,the laser beam irradiated area on the specimen was melt and depressed,causing fracture on the border area,and finally being damaged.
Thermal and mechanical response,stress statute,deformation and damage of pre-pulled,pre-pressed and pre twisted LY12 aluminum alloy specimens caused by irradiation of high-power CW CO2 laser beam were studied in this paper.The parameters of laser irradiation and the microstructure of laser irradiated area were analyzed for different types of pre loading and different shapes of specimens. Under the combined laser beam irradiation and mechnical pre-loading,the laser beam irradiated area on the specimen was melt and depressed,causing fracture on the border area,and finally being damaged.
