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RSS2000 Vol. 24, No. 3
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2000, 24(3): 129-133.
[Abstract]
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Abstract:
crystal are used as the gain medium and amplification medium to configurate the high performance lasers with extra-short pulses of femto-second level,high power output of 100 TW grade and wide tunning range.This paper summarized the new progress of Ti:Al2O3lasers based on CPA technique systematically,described the developing process of Ti:Al2O3lasers and the new important ad-vance.The Ti:Al2O3laser can be used as the extra-short laser pulse source to generate the extra-short X ray,or other applications.
crystal are used as the gain medium and amplification medium to configurate the high performance lasers with extra-short pulses of femto-second level,high power output of 100 TW grade and wide tunning range.This paper summarized the new progress of Ti:Al2O3lasers based on CPA technique systematically,described the developing process of Ti:Al2O3lasers and the new important ad-vance.The Ti:Al2O3laser can be used as the extra-short laser pulse source to generate the extra-short X ray,or other applications.
2000, 24(3): 134-140.
Abstract:
On the experimental basis of the absorption spectrum,excited spectrum and emission spectrum of Er3+-doped Mg-Al spinel crystal,we fined that there are two main absorption lines of wavelength 380nm and 522nm in its absorption spectrum,three strong fluorescence lines of 528nm, 536nm and 549nm and other fluorescence lines in green range.Based on these results,we can calculate the spectrum parameters,such as resonator strength relative to energy transition,transition probabilities of self irradiation, irradiation life and integrated irradiation section.So,we can employ Er:MA spinel crystal to build a novel laser operating at green band or 1.50μm.
On the experimental basis of the absorption spectrum,excited spectrum and emission spectrum of Er3+-doped Mg-Al spinel crystal,we fined that there are two main absorption lines of wavelength 380nm and 522nm in its absorption spectrum,three strong fluorescence lines of 528nm, 536nm and 549nm and other fluorescence lines in green range.Based on these results,we can calculate the spectrum parameters,such as resonator strength relative to energy transition,transition probabilities of self irradiation, irradiation life and integrated irradiation section.So,we can employ Er:MA spinel crystal to build a novel laser operating at green band or 1.50μm.
2000, 24(3): 141-144.
Abstract:
In this paper, a system for laser welding diamond saw blades is introduced. The system is made of CO2 laser source excited by confined discharge,a three position workbench for laser beam transformation,a welding worktable and welding fixtures. The system has been experimentally used to select the process parameters,and we found that the optimum laser power was in the range of 800W～930W, the welding speed was from 20mm/s to 30mm/s.
In this paper, a system for laser welding diamond saw blades is introduced. The system is made of CO2 laser source excited by confined discharge,a three position workbench for laser beam transformation,a welding worktable and welding fixtures. The system has been experimentally used to select the process parameters,and we found that the optimum laser power was in the range of 800W～930W, the welding speed was from 20mm/s to 30mm/s.
2000, 24(3): 145-147.
Abstract:
A laser damage facilities,which has mm size spot and operates in TEM00 mode, were achieved.In order to know the reasons of laser damage,the laser energy density was controlled near the damage threshold of the oxide thin films.According to the examined near threshold damage morphology,the damage mechanisms of the optical coatings can be divided into two types.One was caused by melting of the coating materials,another by exploding,induced with the inner stress of the film.The plasma generated was an important reason to expand the damage area.
A laser damage facilities,which has mm size spot and operates in TEM00 mode, were achieved.In order to know the reasons of laser damage,the laser energy density was controlled near the damage threshold of the oxide thin films.According to the examined near threshold damage morphology,the damage mechanisms of the optical coatings can be divided into two types.One was caused by melting of the coating materials,another by exploding,induced with the inner stress of the film.The plasma generated was an important reason to expand the damage area.
2000, 24(3): 148-150.
Abstract:
In some applcation fields,the square laser pulses are necessary.The conventional cavity flow empty lasers can obtain the pulse output with 10ns pulse width,but not the square laser pulses.In our theoretical analysis,the computer simulation was carried out to fine the solution of the rate equation and to get the relation of the photon number and the Q index.So we can control the photon number of the process of the cavity flow empty to obtain the square laser pulses by adjusting Q index.The experiments were carried out.We supplied a adjustable voltage on the Pockels' cell to control the Q index in the process of cavity flowing empty,and the experiment results show that square laser pulses with the width of 40～70ns can obtain.
In some applcation fields,the square laser pulses are necessary.The conventional cavity flow empty lasers can obtain the pulse output with 10ns pulse width,but not the square laser pulses.In our theoretical analysis,the computer simulation was carried out to fine the solution of the rate equation and to get the relation of the photon number and the Q index.So we can control the photon number of the process of the cavity flow empty to obtain the square laser pulses by adjusting Q index.The experiments were carried out.We supplied a adjustable voltage on the Pockels' cell to control the Q index in the process of cavity flowing empty,and the experiment results show that square laser pulses with the width of 40～70ns can obtain.
2000, 24(3): 151-154.
Abstract:
Stokes wave amplification in double Brillouin cell has beed investigated. The experimental results shows that the gain is determined by the intensity of input Stokes signal and the coupled case with the pump beam. The gain factor of 67 and the better phase conjugation are obtained when the input Stokes intensity is 0.15mJ and at the optimum coupled case.
Stokes wave amplification in double Brillouin cell has beed investigated. The experimental results shows that the gain is determined by the intensity of input Stokes signal and the coupled case with the pump beam. The gain factor of 67 and the better phase conjugation are obtained when the input Stokes intensity is 0.15mJ and at the optimum coupled case.
2000, 24(3): 155-157.
Abstract:
The excimer lasers are novel laser source for industry procedure.In order to obtain the optimum process parameters for various processing condition,we have to now the laser beam quality characteristic, such as energy stability of laser pulses sequences,laser pulse duration and its stability,beam divergence and its stability and energy distribution on spot,except for operating wavelength,maximum pulse energy,pulse repetition and average power.So we used a set of dignotic techniques to evaluate the beam quality of Lambda Physik LPX 305iF KrF laser for excimer laser micro-machining.
The excimer lasers are novel laser source for industry procedure.In order to obtain the optimum process parameters for various processing condition,we have to now the laser beam quality characteristic, such as energy stability of laser pulses sequences,laser pulse duration and its stability,beam divergence and its stability and energy distribution on spot,except for operating wavelength,maximum pulse energy,pulse repetition and average power.So we used a set of dignotic techniques to evaluate the beam quality of Lambda Physik LPX 305iF KrF laser for excimer laser micro-machining.
2000, 24(3): 158-162.
Abstract:
We show three wavelength conversion technologies based on XGM, XPM and FWM of SOA. We introduce their principles, characters and useful experiment setups for the future alloptical WDM network.
We show three wavelength conversion technologies based on XGM, XPM and FWM of SOA. We introduce their principles, characters and useful experiment setups for the future alloptical WDM network.
2000, 24(3): 163-166.
Abstract:
Based on Mie scattering theory,the basic principle and test method to evaluate air solid two phase particle distribution and mean concentration is presented.A series of experiments have been made to prove the theory with the powder of aluminum oxide in an air-particle free jet.
Based on Mie scattering theory,the basic principle and test method to evaluate air solid two phase particle distribution and mean concentration is presented.A series of experiments have been made to prove the theory with the powder of aluminum oxide in an air-particle free jet.
2000, 24(3): 167-170.
Abstract:
In this paper, the physical mechanism and research progress of photorefractive spatial optical solitons are introduced summarily, and the applied prospects of photorefractive spatial optical solitons are also forecasted.
In this paper, the physical mechanism and research progress of photorefractive spatial optical solitons are introduced summarily, and the applied prospects of photorefractive spatial optical solitons are also forecasted.
2000, 24(3): 171-173.
Abstract:
The techniques of preparing PMMA/DR1 periodic waveguide on polymer film by photobleaching method have been studied in this paper. The grating coupler was realized in our experiment. The effective refractive index change was determined by measuring the direction change of the outcoupled beam during photobleaching.
The techniques of preparing PMMA/DR1 periodic waveguide on polymer film by photobleaching method have been studied in this paper. The grating coupler was realized in our experiment. The effective refractive index change was determined by measuring the direction change of the outcoupled beam during photobleaching.
2000, 24(3): 174-178.
Abstract:
The recent research progress of optical fiber sensor was reviewed in this paper.Based on the wide application requirements,the researches of optical fiber sensors mainly focus on four fields:(1)transverse strain optical fiber sensor;(2)high sensitivity and high resolution fiber sensor;(3)low cast and high sensitive detection technology;(4)the most active filed is practical application technology of fiber sensors,including package technique,temperature compesation technique and sensors network technology.
The recent research progress of optical fiber sensor was reviewed in this paper.Based on the wide application requirements,the researches of optical fiber sensors mainly focus on four fields:(1)transverse strain optical fiber sensor;(2)high sensitivity and high resolution fiber sensor;(3)low cast and high sensitive detection technology;(4)the most active filed is practical application technology of fiber sensors,including package technique,temperature compesation technique and sensors network technology.
2000, 24(3): 179-181.
Abstract:
The frosting rate of the evaporator interface is an important parameter for designing the refrigerator system.In this paper,we described a novel technique of laser diffraction measurement technique to visually and fast determine the frosting rate.There was a space between the frosted surface and the reference surface.When a light went through the space,the diffraction fringes were performed.Then the frosted area expended,the space changed more narrow,and the diffraction fringes moved.With the variation of the location of the diffraction fringes,the frost rate can be precisely determined.
The frosting rate of the evaporator interface is an important parameter for designing the refrigerator system.In this paper,we described a novel technique of laser diffraction measurement technique to visually and fast determine the frosting rate.There was a space between the frosted surface and the reference surface.When a light went through the space,the diffraction fringes were performed.Then the frosted area expended,the space changed more narrow,and the diffraction fringes moved.With the variation of the location of the diffraction fringes,the frost rate can be precisely determined.
2000, 24(3): 182-184.
Abstract:
Laser device in IJL88-200 laser rangefinder is refitted by adjustfree one.Comparative tests are made between them,the results are ideal.
Laser device in IJL88-200 laser rangefinder is refitted by adjustfree one.Comparative tests are made between them,the results are ideal.
2000, 24(3): 185-188.
Abstract:
The measurement of laser induced damage optical surface play an important role in development of laser weapon or the National Ignition Facility.In this paper, by combining with the experiment, we comment on the defects and advantages of two measurement method,i.e. one on macro measurement of the reflectivity of He Ne laser, and other on micro measurement of the topography for damage spot.
The measurement of laser induced damage optical surface play an important role in development of laser weapon or the National Ignition Facility.In this paper, by combining with the experiment, we comment on the defects and advantages of two measurement method,i.e. one on macro measurement of the reflectivity of He Ne laser, and other on micro measurement of the topography for damage spot.
2000, 24(3): 189-191.
Abstract:
This paper reports the different laser operation methods.The treatment results are generally satisfactory.The complication after laser therapy and prognosis were discussed.
This paper reports the different laser operation methods.The treatment results are generally satisfactory.The complication after laser therapy and prognosis were discussed.
2000, 24(3): 192-195.
Abstract:
In this paper,the development of PSD in land and abroad are briefly introduced,and some experiments for the study of the effects of the light source on the position precision of PSD are performed as well.It is proved that the fluctuation of the light intensity can lead to the loss of the position precision of PSD,the results are far from those derived from theoretical analysis:there is no effect of light intensity on the position precision.At the same time,the experiments also show that the size and shape of the light speckle can also exert certain effects on the ultimate position precision.
In this paper,the development of PSD in land and abroad are briefly introduced,and some experiments for the study of the effects of the light source on the position precision of PSD are performed as well.It is proved that the fluctuation of the light intensity can lead to the loss of the position precision of PSD,the results are far from those derived from theoretical analysis:there is no effect of light intensity on the position precision.At the same time,the experiments also show that the size and shape of the light speckle can also exert certain effects on the ultimate position precision.
