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RSS1995 Vol. 19, No. 3
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1995, 19(3): 129-134.
[Abstract]
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Abstract:
The temporal characteristics of tunable solid-state laser pumped by a Q-switched laser are studied theoreticall The formulas of the buildup time and the pulse-width of the oscillating mode for vibronic solid-state lasers with lifetime um-magtitude,pumped by a laser with 10 ns magtitude pulse-width which are shorter compared to the buildup time of the oscillating mode,have deduced.The theoretical model gain switch-ing model predicts that the temporal characteristics of the laser,the buildup time and the pulse-width are dependent only on the pumping energy level and cavity length.
The temporal characteristics of tunable solid-state laser pumped by a Q-switched laser are studied theoreticall The formulas of the buildup time and the pulse-width of the oscillating mode for vibronic solid-state lasers with lifetime um-magtitude,pumped by a laser with 10 ns magtitude pulse-width which are shorter compared to the buildup time of the oscillating mode,have deduced.The theoretical model gain switch-ing model predicts that the temporal characteristics of the laser,the buildup time and the pulse-width are dependent only on the pumping energy level and cavity length.
1995, 19(3): 135-140.
Abstract:
The perpetual laser damage effects of silicon PIN photoelectric diodes and silicon avalanche photodiodes irradiated by a laser of 1.06μm or 0.53μm wavelength are studied.The laser damage thresholds of the detectors are experimentally measured.The main reason of causing the perpetual damage are the laser heat singe on the PN connect of photoelectric diodes.The damage thresholds are relative to the laser wavelength,pulse width and the photodiod structure.
The perpetual laser damage effects of silicon PIN photoelectric diodes and silicon avalanche photodiodes irradiated by a laser of 1.06μm or 0.53μm wavelength are studied.The laser damage thresholds of the detectors are experimentally measured.The main reason of causing the perpetual damage are the laser heat singe on the PN connect of photoelectric diodes.The damage thresholds are relative to the laser wavelength,pulse width and the photodiod structure.
1995, 19(3): 141-145.
Abstract:
The forward LDV has wider applications than the backward LDV,because of its lower requirements of the laser power.In practical measurements,due tolimited circumstance,the backward LDV also must be used.In this paper,the light splitting system and the light receiving system of the different forward LDV have beenstudied,and an important method is provided to make forward LDV have the function to be used as backward LDV. The experimental results show the method is very well,so the method can be wide used in practical applications.
The forward LDV has wider applications than the backward LDV,because of its lower requirements of the laser power.In practical measurements,due tolimited circumstance,the backward LDV also must be used.In this paper,the light splitting system and the light receiving system of the different forward LDV have beenstudied,and an important method is provided to make forward LDV have the function to be used as backward LDV. The experimental results show the method is very well,so the method can be wide used in practical applications.
1995, 19(3): 146-149.
Abstract:
Based on the photoconductive effect of the semiconductor,the photo-conductive switch has been developed.The photoconductive switch is biased at 4kV bias voltage,and can generate a electrical pulse in 50 ohm load with peak voltage～1.8kV,peak power～65kW and 16ns duration,when the switch is triggered by a laser pulse with 12 ns pulsewidth.In this paper,the keytechnologies of the photoconductive switch,such as dark resistance. carrier life、constant resistance etc,are described.
Based on the photoconductive effect of the semiconductor,the photo-conductive switch has been developed.The photoconductive switch is biased at 4kV bias voltage,and can generate a electrical pulse in 50 ohm load with peak voltage～1.8kV,peak power～65kW and 16ns duration,when the switch is triggered by a laser pulse with 12 ns pulsewidth.In this paper,the keytechnologies of the photoconductive switch,such as dark resistance. carrier life、constant resistance etc,are described.
1995, 19(3): 150-154.
Abstract:
The technology of laser Doppler velocity measurement in fluid depends on the presence of suitable particles. How to choose the scattering particles during mea-suring turbulent flow field with particle dynamic analyzer(PDA)is discussed in this pa-per.The results show:(1)The choice of scattering particle is the main factor of influe-ncing the velocity measurement;(2)In the study of turbulent flow field by PDA,the requirements of scattering particle choice are mainly small size,low particle density,high particle refractive index and suitable concentration.
The technology of laser Doppler velocity measurement in fluid depends on the presence of suitable particles. How to choose the scattering particles during mea-suring turbulent flow field with particle dynamic analyzer(PDA)is discussed in this pa-per.The results show:(1)The choice of scattering particle is the main factor of influe-ncing the velocity measurement;(2)In the study of turbulent flow field by PDA,the requirements of scattering particle choice are mainly small size,low particle density,high particle refractive index and suitable concentration.
1995, 19(3): 154-157.
Abstract:
Using FROI as a coupler in Nd-glass round-trip amplifier,the isolationcoefficient of over 100 in a round-trip amplifier has been obtained. It is analysed the in-fluence of the limited beem-diameter and incident beem direction to the isolation coeffi-clent .
Using FROI as a coupler in Nd-glass round-trip amplifier,the isolationcoefficient of over 100 in a round-trip amplifier has been obtained. It is analysed the in-fluence of the limited beem-diameter and incident beem direction to the isolation coeffi-clent .
1995, 19(3): 158-163.
Abstract:
In research of measureing the distribution of infrared powerful laser power density,we put forward the method of moving narrow chink sampling and pro-cessing the sampling pictures to obtain laser beam power density distribution,To raise measurement quality,we advance a method which extends survery-material's measure-ment range and raisies meassurement precision,and discuss the calibration of survery-material hot sensitive briefly,and give relevant experiment conclusion.
In research of measureing the distribution of infrared powerful laser power density,we put forward the method of moving narrow chink sampling and pro-cessing the sampling pictures to obtain laser beam power density distribution,To raise measurement quality,we advance a method which extends survery-material's measure-ment range and raisies meassurement precision,and discuss the calibration of survery-material hot sensitive briefly,and give relevant experiment conclusion.
1995, 19(3): 164-170.
Abstract:
Based on the three-dimensional ray tracing and aberration calculations,the off-axis mirror line focus system used in SERC Rutherford Appleton Laboratory is analyzed.Then,two types of novel reflective line focus geometry for X-ray laser experi-ments,namely,the reflective wedge array and conical lens array systems,are first pro-posed and illustrated with numerical examples.Finally,the results are compared and discussed.
Based on the three-dimensional ray tracing and aberration calculations,the off-axis mirror line focus system used in SERC Rutherford Appleton Laboratory is analyzed.Then,two types of novel reflective line focus geometry for X-ray laser experi-ments,namely,the reflective wedge array and conical lens array systems,are first pro-posed and illustrated with numerical examples.Finally,the results are compared and discussed.
1995, 19(3): 171-173.
Abstract:
The transmission spectra in near ultraviolet and visible regions and the spectra variation resulted from He-Ne laser irradiation of PVA film have been experi-mentally observed and measured.The experimental results are useful to developing of photoelectric technology and photocontrolled elements.
The transmission spectra in near ultraviolet and visible regions and the spectra variation resulted from He-Ne laser irradiation of PVA film have been experi-mentally observed and measured.The experimental results are useful to developing of photoelectric technology and photocontrolled elements.
1995, 19(3): 174-178.
Abstract:
A high-current-density,fast pulse discharge device has been developed,The device is used to excite He/K mixed vapor,and the Penning ionization of K byHe(6d￣3D),HeB(5s￣1S)and He(4p￣1P_0)is observed in discharge afterflow.
A high-current-density,fast pulse discharge device has been developed,The device is used to excite He/K mixed vapor,and the Penning ionization of K byHe(6d￣3D),HeB(5s￣1S)and He(4p￣1P_0)is observed in discharge afterflow.
1995, 19(3): 179-181.
Abstract:
In the experiment study,a bioutput OE prism is used to determine the directions of two perpendicular linear polarized laser beams from a He-Ne laser without Brewster windows. The results show that the intensity stability of the linear polarized laser beam can be much similar to the intensity stability of total laser beam if the prism is at an angle about 45 degree with two perpendicular linear polarized laser beams. In practical applications,the method is convenient,feasible,and worth considering.
In the experiment study,a bioutput OE prism is used to determine the directions of two perpendicular linear polarized laser beams from a He-Ne laser without Brewster windows. The results show that the intensity stability of the linear polarized laser beam can be much similar to the intensity stability of total laser beam if the prism is at an angle about 45 degree with two perpendicular linear polarized laser beams. In practical applications,the method is convenient,feasible,and worth considering.
1995, 19(3): 182-185.
Abstract:
In this paper,the performance of four laser acupuncture irradiation and moixibustion instruments is compared from the point of laser penetration depth and en-ergy distribution in humman skin. Some suggestions are given on their clinical applica-tions.
In this paper,the performance of four laser acupuncture irradiation and moixibustion instruments is compared from the point of laser penetration depth and en-ergy distribution in humman skin. Some suggestions are given on their clinical applica-tions.
1995, 19(3): 186-190.
Abstract:
As intelligent laser spot meter controlled by a single chip micro-con-troller is described in this paper.
As intelligent laser spot meter controlled by a single chip micro-con-troller is described in this paper.
1995, 19(3): 191-193.
Abstract:
The treatment of pericornitise of wisdom tooth using He-Ne laser is re-ported and the results show that,this treatment has satisfactory clinical effect.
The treatment of pericornitise of wisdom tooth using He-Ne laser is re-ported and the results show that,this treatment has satisfactory clinical effect.
