Journals >Chinese Journal of Lasers
Contents
2001
Volume: 28 Issue 12
20 Article(s)
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Research Article
A Device in Capillary Discharge Pumped Table-top X-ray Laser
[in Chinese], [in Chinese], [in Chinese], and [in Chinese]
According to the mechanics of capillary discharge by electron collision excitation regimes in Ne-like Ar, a capillary discharge device was designed on a Marx generator whose maximum output voltage is only 300 kV. The test was systematically proceed. At capillary charge filled with Ar gas, output current of 38 kA, curreAccording to the mechanics of capillary discharge by electron collision excitation regimes in Ne-like Ar, a capillary discharge device was designed on a Marx generator whose maximum output voltage is only 300 kV. The test was systematically proceed. At capillary charge filled with Ar gas, output current of 38 kA, current pulse rising edge of 40ns was attained. At present, the experiment study of fluorescence spectra was developing on capillary discharge in Ne-like Ar..
Chinese Journal of Lasers
- Publication Date: Jan. 01, 1900
- Vol. 28, Issue 12, 1071 (2001)
Forward-pumping Dual-stage Double-pass Broadband Erbium-doped Fiber Source
[in Chinese], [in Chinese], [in Chinese], and [in Chinese]
A forward-pumping dual-stage double-pass erbium-doped fiber source at 1.55 μm is presented and experimentally demonstrated. Broadband, high-power characteristics can be obtained simultaneously while reserving the high stability of the mean wavelength by appropriately choosing the source parameters, including the lengthA forward-pumping dual-stage double-pass erbium-doped fiber source at 1.55 μm is presented and experimentally demonstrated. Broadband, high-power characteristics can be obtained simultaneously while reserving the high stability of the mean wavelength by appropriately choosing the source parameters, including the length of two sections of erbium-doped fiber and the pump power of two stages. Such a fiber source is an excellent candidate for the fiber-optic gyroscope (FOG)..
Chinese Journal of Lasers
- Publication Date: Jan. 01, 1900
- Vol. 28, Issue 12, 1075 (2001)
Surface Plasma Wave Sub-nanometer Indicating System
[in Chinese], [in Chinese], and [in Chinese]
A new method for nanometer positioning based on surface plasma wave is reported. A fiber probe approaching a coated prism can be equivalent to a four-layer prism-metal-air-fiber system. Analysis of the near-field beam intensity entering the fiber probe is presented. Theoretical analysis shows that the intensity couplinA new method for nanometer positioning based on surface plasma wave is reported. A fiber probe approaching a coated prism can be equivalent to a four-layer prism-metal-air-fiber system. Analysis of the near-field beam intensity entering the fiber probe is presented. Theoretical analysis shows that the intensity coupling into the fibre probe changes according to the thickness of air gap. Non-contact nanometer indicating system can be set up according to this characteristic. Experiments show that standard deviation of 2 nm and resolution of 0.1 nm/nV in 20 minutes procedure of positioning repeatability can be achieved under air conditioning of ±1℃/h..
Chinese Journal of Lasers
- Publication Date: Jan. 01, 1900
- Vol. 28, Issue 12, 1079 (2001)
Fabrication of 8-element Linear VOx Uncooled Microbolometer IR Detector Array
[in Chinese], [in Chinese], [in Chinese], [in Chinese], [in Chinese], and [in Chinese]
The paper describes VO x thin films deposited on substrates of quartz glass and Si (100) by reactive ion-beam sputtering followed by post annealing, and fabrication of 8-element VO x linear uncooled microbolometer array. SEM and XRD indicate that the films are smooth compact surface morphology with needle like grain anThe paper describes VO x thin films deposited on substrates of quartz glass and Si (100) by reactive ion-beam sputtering followed by post annealing, and fabrication of 8-element VO x linear uncooled microbolometer array. SEM and XRD indicate that the films are smooth compact surface morphology with needle like grain and poly-crystal structure of mixed vanadium oxides, and the characterization of the detectors shows that the detectors realize uncooled infrared detection in the spectrum region of 8～12 μm as well..
Chinese Journal of Lasers
- Publication Date: Jan. 01, 1900
- Vol. 28, Issue 12, 1082 (2001)
Biomedical Photonics and Laser Medicine
Study on Experiment of Ar+ Laser Coagulation of Vas Deferens and Its Clinical Application
[in Chinese], [in Chinese], and [in Chinese]
An experiment of Ar + laser coagulation of vas deferens which made on animals is reported. The experiment proved that Ar + laser coagulation technique can be apllied to clinic. It can reduce the postoperative complication and the patient′s moral pressure and pain.An experiment of Ar + laser coagulation of vas deferens which made on animals is reported. The experiment proved that Ar + laser coagulation technique can be apllied to clinic. It can reduce the postoperative complication and the patient′s moral pressure and pain..
Chinese Journal of Lasers
- Publication Date: Jan. 01, 1900
- Vol. 28, Issue 12, 1130 (2001)
Holography and Information Processing
Optical A/D Conversion by Time-interweaved Sampling
[in Chinese], [in Chinese], [in Chinese], and [in Chinese]
A time-interweaved sampling scheme for optical A/D conversion is proposed, and 16×2.5 GHz sampling rate to microwave signal was realized. The sampling errors are analysed and the methods to improve sampling precision are discussed. The experiment result was revised and SNR is about 29 dB.A time-interweaved sampling scheme for optical A/D conversion is proposed, and 16×2.5 GHz sampling rate to microwave signal was realized. The sampling errors are analysed and the methods to improve sampling precision are discussed. The experiment result was revised and SNR is about 29 dB..
Chinese Journal of Lasers
- Publication Date: Jan. 01, 1900
- Vol. 28, Issue 12, 1096 (2001)
Realization of Non-volatile Holographic Storage in LiNbO3:Cu:Ce Crystals with Two Illumination Schemes
[in Chinese], [in Chinese], [in Chinese], [in Chinese], and [in Chinese]
Realization of non-volatile holographic storage in LiNbO 3∶Cu∶Ce crystals with two illumination schemes is reported in this paper, one is with ultraviolet light for sensitization and red light recording proposed by Buse et al., and the other is with 458 nm blue light from Ar + laser for sensitization and red light recoRealization of non-volatile holographic storage in LiNbO 3∶Cu∶Ce crystals with two illumination schemes is reported in this paper, one is with ultraviolet light for sensitization and red light recording proposed by Buse et al., and the other is with 458 nm blue light from Ar + laser for sensitization and red light recording. It is shown that the fixed (nonvolatile) diffraction efficiency and the fixing efficiency with the second scheme are higher than those with the first scheme, but the second scheme causes weakly light-induced scattering. When the optimal intensity of blue light is around 700 W/m 2, the nonvolatile refractive-index change is up to 5×10 -5..
Chinese Journal of Lasers
- Publication Date: Jan. 01, 1900
- Vol. 28, Issue 12, 1099 (2001)
Laser Manufacturing
Calculation of Heat Interaction between a Series of the Laser Pulses and the Material
[in Chinese]
In this paper, the calculation equation of the transient temperature field in the material acted by the continuous and pulse laser, which distributions of power density close to the reality, is presented and an applied example is given. The results make things convenient for the application.In this paper, the calculation equation of the transient temperature field in the material acted by the continuous and pulse laser, which distributions of power density close to the reality, is presented and an applied example is given. The results make things convenient for the application..
Chinese Journal of Lasers
- Publication Date: Jan. 01, 1900
- Vol. 28, Issue 12, 1120 (2001)
Study of YAG Laser Cutting Process with Stainless Steel Sheet
[in Chinese], [in Chinese], [in Chinese], [in Chinese], and [in Chinese]
In this paper, the experiments of cutting stainless steel sheet with Nd∶YAG pulse laser, were carried out. The effects of laser process parameters on kerf width and quality were studied. The results showed that the kerf width increases with the increase of the power density, pulse frequency and pulse width; the cuttingIn this paper, the experiments of cutting stainless steel sheet with Nd∶YAG pulse laser, were carried out. The effects of laser process parameters on kerf width and quality were studied. The results showed that the kerf width increases with the increase of the power density, pulse frequency and pulse width; the cutting speed is increased and the cutting quality is improved with increasing the pulse frequency. Besides, the calculation formulas of the overlapping degree of the neighboring laser pulse and the maximum cutting speed are deduced..
Chinese Journal of Lasers
- Publication Date: Jan. 01, 1900
- Vol. 28, Issue 12, 1125 (2001)
Laser Physics
Wavelength Tunable Single Ridge Waveguide Electroabsorption Modulated DFB Laser
[in Chinese], [in Chinese], [in Chinese], [in Chinese], [in Chinese], and [in Chinese]
A new type wavelength tunable electroabsorption modulated DFB laser (T-EML) by using a thin-film heater is proposed and successfully fabricated. The EML tuning range amounts to 2.2 nm with a 3.8 nm/W tuning efficiency. In the tuning range, the EML output power variation is less than 3 dB, the extinction ratio variationA new type wavelength tunable electroabsorption modulated DFB laser (T-EML) by using a thin-film heater is proposed and successfully fabricated. The EML tuning range amounts to 2.2 nm with a 3.8 nm/W tuning efficiency. In the tuning range, the EML output power variation is less than 3 dB, the extinction ratio variation is very little and the side mode suppression is maintained more than 30 dB. A wavelength fast tunable EML by using phase tuning is also proposed. By using the facet effective reflectivity method and the coupling wave theory, the tuning range of the phase tuning EML is about 3.2 nm from calculation. A wide range and fast tunable EML can be achieved by using thermal and phase tuning..
Chinese Journal of Lasers
- Publication Date: Jan. 01, 1900
- Vol. 28, Issue 12, 1057 (2001)
Broadly Tunable Room-temperature Operation Co:MgF2 Laser
[in Chinese], [in Chinese], [in Chinese], [in Chinese], [in Chinese], and [in Chinese]
Different order of interference with birefringent filter and sets of mirror were applied to room-temperature operation of Co∶MgF 2 tunable laser. A laser with continuous tuning range from 1700 nm to 2550 nm with output energy up to 115 mJ and 16% conversion efficiency at 2090 nm peak wavelength was obtained.Different order of interference with birefringent filter and sets of mirror were applied to room-temperature operation of Co∶MgF 2 tunable laser. A laser with continuous tuning range from 1700 nm to 2550 nm with output energy up to 115 mJ and 16% conversion efficiency at 2090 nm peak wavelength was obtained..
Chinese Journal of Lasers
- Publication Date: Jan. 01, 1900
- Vol. 28, Issue 12, 1061 (2001)
Smooth-pulse Nd:YAG Q-switched Oscillator Coupled with Three-plan Resonant Reflector
[in Chinese], and [in Chinese]
Optical resonant reflector (RR), as a coupled-output mirror of Nd∶YAG oscillator, has very strong ability for selecting longitudinal mode. Three-plan RR has more regular structure of modulated reflecting-spectrum. For outputting stable single longitudinal mode, it is optimized for oscillator parametric designing in theOptical resonant reflector (RR), as a coupled-output mirror of Nd∶YAG oscillator, has very strong ability for selecting longitudinal mode. Three-plan RR has more regular structure of modulated reflecting-spectrum. For outputting stable single longitudinal mode, it is optimized for oscillator parametric designing in theory and it is suggested that the oscillator should operate near threshold for full utilizing the mode selecting ability of RR. Great than 97% smooth pulses, with 17 mJ, are obtained in experiment..
Chinese Journal of Lasers
- Publication Date: Jan. 01, 1900
- Vol. 28, Issue 12, 1063 (2001)
Non-paraxial Propagation of Optical Beams in Nonlinear Self-focusing Media
[in Chinese], and [in Chinese]
A non-paraxial equation for nonlinear optical propagation in the scalar approximation is derived. As a first-order correction, it is shown that the nonparaxiality can be expressed with a fourth-order spatial dispersion and fifth-order nonlinearity. By using variational approach to the modified nonlinear equation the prA non-paraxial equation for nonlinear optical propagation in the scalar approximation is derived. As a first-order correction, it is shown that the nonparaxiality can be expressed with a fourth-order spatial dispersion and fifth-order nonlinearity. By using variational approach to the modified nonlinear equation the propagation properties of Gaussian beams are obtained. It is found that the beam propagates stably with a focusing-defocusing cycle, and the beam with a higher power has a smaller cycle. It is also shown that the self-focusing process can be controlled by changing the chirp parameters. The positive (negative) chirp reduces (increases) the initial self-focusing length and both chirps increase the focusing-defocusing cycle..
Chinese Journal of Lasers
- Publication Date: Jan. 01, 1900
- Vol. 28, Issue 12, 1066 (2001)
Measurement and Metrology
Characteristics of Q-switched CO2 Short-pulse Heterodyne Signal with CdTe Electrooptic Modulator
[in Chinese], [in Chinese], [in Chinese], and [in Chinese]
In this paper, the properties of time and frequency domain of pulsed CO 2 laser difference frequency signals with CdTe electrooptic modulator are studied in detail. The long pulse trailing is found in time domain, and the trailing time bear a relation to outer trigger voltage of CdTe crystal. If it is very weak, the puIn this paper, the properties of time and frequency domain of pulsed CO 2 laser difference frequency signals with CdTe electrooptic modulator are studied in detail. The long pulse trailing is found in time domain, and the trailing time bear a relation to outer trigger voltage of CdTe crystal. If it is very weak, the pulse signals can hardly be received through direct detection. In this case, the strong difference frequency signals from pulse trailing will be received if heterodyne detection is used. According to the controllability to trailing time, the possibility of intermediate frequency signals trace and frequency-offset lock between short-pulse transmitter and CW local oscillator light in pulse laser heterodyne is discussed..
Chinese Journal of Lasers
- Publication Date: Jan. 01, 1900
- Vol. 28, Issue 12, 1085 (2001)
Study on the Laser Ablation Threshold of Copper Using Laser Beam Deflection Technique
[in Chinese], [in Chinese], [in Chinese], and [in Chinese]
Based on the principle of probe beam deflection, three methods have been used to measure the ablation threshold of Cu. The laser ablation threshold of the solid is determined according to the variation of the energy and transit time of photoacoustic signal and the relation of the positive amplitude deflection signals tBased on the principle of probe beam deflection, three methods have been used to measure the ablation threshold of Cu. The laser ablation threshold of the solid is determined according to the variation of the energy and transit time of photoacoustic signal and the relation of the positive amplitude deflection signals to the laser fluence. A comparison of these methods is made and the conditions for their applications are given..
Chinese Journal of Lasers
- Publication Date: Jan. 01, 1900
- Vol. 28, Issue 12, 1089 (2001)
Studies about the Derivative Field Measurement by Image Processing
[in Chinese], [in Chinese], [in Chinese], [in Chinese], [in Chinese], and [in Chinese]
This paper proposes a new method to measure the slope of a deformation, which is based on image processing and need no shear instrument. From a common fringe image, it can get the corresponding fringe image of a slope at any resolution in any direction.This paper proposes a new method to measure the slope of a deformation, which is based on image processing and need no shear instrument. From a common fringe image, it can get the corresponding fringe image of a slope at any resolution in any direction..
Chinese Journal of Lasers
- Publication Date: Jan. 01, 1900
- Vol. 28, Issue 12, 1093 (2001)
Optical Communication
Study on the Characteristic of Polarization Mode Dispersion in WDM Systems
[in Chinese], [in Chinese], and [in Chinese]
The coupled nonlinear Schr*idinger equations for two wavelength optical pulses in a birefringence fiber are given. The model for treating polarization mode dispersion in two channels WDM system is established. Based on this model, optical signal propagation behaviors in two channels WDM with polarization mode dispersioThe coupled nonlinear Schr*idinger equations for two wavelength optical pulses in a birefringence fiber are given. The model for treating polarization mode dispersion in two channels WDM system is established. Based on this model, optical signal propagation behaviors in two channels WDM with polarization mode dispersion are numerically simulated. The influences of polarization mode dispersion on two channels WDM system are also analyzed..
Chinese Journal of Lasers
- Publication Date: Jan. 01, 1900
- Vol. 28, Issue 12, 1103 (2001)
An Analytical Expression for the Impact of Rayleigh Scattering on Distributed Fiber Raman Amplifiers
[in Chinese], [in Chinese], and [in Chinese]
Rayleigh scattering in the transmission fiber will degrade the noise performance of fiber Raman amplifiers. In this paper, considering the impact of Rayleigh scattering in the transmission fiber, an analytical expression for the equivalent noise figure in a distributed fiber Raman amplifier is derived. This analytical Rayleigh scattering in the transmission fiber will degrade the noise performance of fiber Raman amplifiers. In this paper, considering the impact of Rayleigh scattering in the transmission fiber, an analytical expression for the equivalent noise figure in a distributed fiber Raman amplifier is derived. This analytical expression is used to analyze the impact of Rayleigh scattering on the noise performance of a distributed fiber Raman amplifier and discuss the rule of pump power selection..
Chinese Journal of Lasers
- Publication Date: Jan. 01, 1900
- Vol. 28, Issue 12, 1108 (2001)
Generalized Attenuation Coefficient and a Novel Simulation Method of Raman Fiber Amplifiers
[in Chinese], and [in Chinese]
With the introduction of generalized attenuation coefficient, a novel simulation method for fiber Raman amplifier (FRA) is proposed. The assumption of equal signal and pump attenuation coefficients is no longer required, while the iteration step-size can be significantly enlarged even under saturated amplification. UsiWith the introduction of generalized attenuation coefficient, a novel simulation method for fiber Raman amplifier (FRA) is proposed. The assumption of equal signal and pump attenuation coefficients is no longer required, while the iteration step-size can be significantly enlarged even under saturated amplification. Using this novel method in FRA simulation leads to obvious reduction of iteration time with saturated accuracy. The simulation results argree well with the experimental data..
Chinese Journal of Lasers
- Publication Date: Jan. 01, 1900
- Vol. 28, Issue 12, 1113 (2001)
Optimal Design of Er-doped Fiber-optic Amplifiers
[in Chinese], and [in Chinese]
The performance of high gain, lower noise figure and gain flatness is investigated in design of a two-stage erbium-doped fiber amplifier (EDFA). A new construction of EDFA is proposed.The performance of high gain, lower noise figure and gain flatness is investigated in design of a two-stage erbium-doped fiber amplifier (EDFA). A new construction of EDFA is proposed..
Chinese Journal of Lasers
- Publication Date: Jan. 01, 1900
- Vol. 28, Issue 12, 1117 (2001)
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