Journals >Chinese Journal of Lasers
Contents
1999
Volume: 26 Issue 2
20 Article(s)
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Research Article
Wavelength Optimization of a High-precision Noncontact Dual-wavelength Fiber-optic Pyrometer
[in Chinese], [in Chinese], [in Chinese], [in Chinese], [in Chinese], and [in Chinese]
In this paper, a method of optimal parameter selection for determining two operating wavelengths and their bandwidths of a high-precision noncontact dual-wavelength fiber-optic pyrometer is proposed. In the range of 600～1360℃, an accuracy of 0.5℃ and resolution of 0.1℃ are obtained.In this paper, a method of optimal parameter selection for determining two operating wavelengths and their bandwidths of a high-precision noncontact dual-wavelength fiber-optic pyrometer is proposed. In the range of 600～1360℃, an accuracy of 0.5℃ and resolution of 0.1℃ are obtained..
Chinese Journal of Lasers
- Publication Date: Jan. 01, 1900
- Vol. 26, Issue 2, 121 (1999)
Study on ESPI Technique for Simultaneous Measurement of Whole in-Plane Displacement with the Polarization of Laser
[in Chinese], [in Chinese], and [in Chinese]
A novel ESPI optical set-up is presented for the measurement of the whole field in-plane displacement. The problem of the whole in-plane displacement measurement in the transient or non-repeatable situation can be solved with this technique. The laser beam is splitted into four beams that are arranged in the horizontalA novel ESPI optical set-up is presented for the measurement of the whole field in-plane displacement. The problem of the whole in-plane displacement measurement in the transient or non-repeatable situation can be solved with this technique. The laser beam is splitted into four beams that are arranged in the horizontal and vertical planes, respectively. The optical set-up is arranged according to the laser′s polarization. The polarization directions of the lights in the horizontal plane are the same and so do the lights in the vertical plane. Howerve, the polarization directions in the two planes are orthogonal. The whole field in-plane displacement of a rotating plate is measured with this technique and a satisfactory result has been obtained. The speckle fringes corresponding to horizontal and vertical components are obtained with the same speckle pattern..
Chinese Journal of Lasers
- Publication Date: Jan. 01, 1900
- Vol. 26, Issue 2, 127 (1999)
A Novel Resonant Switching Mode Power Supply for High-power Lasers
[in Chinese], [in Chinese], and [in Chinese]
The prototype of ZCS-SRC (zero current switching-series resonant converter) switching mode power supply for high-power lasers is developed successfully based on a novel resonant technique. Compared with the conventional and PWM hard-switching power supplies, the outstanding technical indexes of the ZCS-SRC which holds The prototype of ZCS-SRC (zero current switching-series resonant converter) switching mode power supply for high-power lasers is developed successfully based on a novel resonant technique. Compared with the conventional and PWM hard-switching power supplies, the outstanding technical indexes of the ZCS-SRC which holds a leading position in China are as follows: operating frequency is 50 kHz, efficiency is 82%, output current is 0～80 mA, and the fluctuation of current is ≤±1 mA. The power supply for the high-power gas laser provides a steady discharge current without the need of any amperites. The discharge current can be adjusted from zero and is independent on gas density and gas pressure..
Chinese Journal of Lasers
- Publication Date: Jan. 01, 1900
- Vol. 26, Issue 2, 131 (1999)
The Measurement of Electrode Parameters of RF Waveguide Lasers
[in Chinese], [in Chinese], [in Chinese], [in Chinese], and [in Chinese]
According to the transmission line theory, the electrodes of RF waveguide lasers can be approximated to a lossless uniform transmission line. By means of a frequency-scanning method, the electrode parameters of RF waveguide lasers, such as the characteristic impedance, phase constant, distributed inductance, and distriAccording to the transmission line theory, the electrodes of RF waveguide lasers can be approximated to a lossless uniform transmission line. By means of a frequency-scanning method, the electrode parameters of RF waveguide lasers, such as the characteristic impedance, phase constant, distributed inductance, and distributed capacitance, etc, can be measured..
Chinese Journal of Lasers
- Publication Date: Jan. 01, 1900
- Vol. 26, Issue 2, 135 (1999)
Interference Measurements for Roughness of Laser Mirrors
[in Chinese], and [in Chinese]
A full-field, noncontacting interference measurement for roughness of laser mirrors has been developed. Suppose the probability density function of the surface height distribution is Gaussian. The relationship between the interference fringes contrast and the ronghness of a mirror is deduced. Two laser mirrors with difA full-field, noncontacting interference measurement for roughness of laser mirrors has been developed. Suppose the probability density function of the surface height distribution is Gaussian. The relationship between the interference fringes contrast and the ronghness of a mirror is deduced. Two laser mirrors with different roughnesses were measured. The data measured are in agreement with the results measured with a 6JA Microscopic Interference Profilometer. The range of measurement is 0.01 to 0.12 μm and the accuracy of measurement is up to 0.002 μm theoretically. Practically, this work may be useful for controlling the process of mirror polishing..
Chinese Journal of Lasers
- Publication Date: Jan. 01, 1900
- Vol. 26, Issue 2, 141 (1999)
Z-scan Measurement of Nonlinear Refractive Indexes of YVO4 Crystal
[in Chinese], [in Chinese], [in Chinese], [in Chinese], and [in Chinese]
The pure yttrium orthovanadate crystal has been widely used in polarizing optics such as beam splitters, prism polarizers and optical isolators. The measurement of the nonlinear refractive index is an important method for the study of the nonlinear optical quality and investigation of optical inherent damages in crystaThe pure yttrium orthovanadate crystal has been widely used in polarizing optics such as beam splitters, prism polarizers and optical isolators. The measurement of the nonlinear refractive index is an important method for the study of the nonlinear optical quality and investigation of optical inherent damages in crystal. We have measured the nonlinear refractive indexes of a YVO4 crystal along the orientations of ［100］ and ［001］ by the “Z-scan” method, and found that the nonlinear refractive indexes are generally equal but opposite..
Chinese Journal of Lasers
- Publication Date: Jan. 01, 1900
- Vol. 26, Issue 2, 145 (1999)
Laser Manufacturing
Microstructure and Dry Sliding Wear of Laser Clad WCp/Ni-Cr-B-Si-C Alloy Composite Coatings
[in Chinese], [in Chinese], [in Chinese], [in Chinese], and [in Chinese]
WCp reinforced Ni-Cr-B-Si-C composite coatings were deposited on AISI1045 steel by laser. The microstructure of the typical coating containing 30vol-% WC particulates was investigated using XRD, SEM and TEM. It was found that partial WC dissolved and decomposed in the laser melt pool during the melting stage of the claWCp reinforced Ni-Cr-B-Si-C composite coatings were deposited on AISI1045 steel by laser. The microstructure of the typical coating containing 30vol-% WC particulates was investigated using XRD, SEM and TEM. It was found that partial WC dissolved and decomposed in the laser melt pool during the melting stage of the cladding. The rapidly solidified microstructure of the laser melt is composed of metastable bar-like α-W2C, blocky β-W2C and quadrilateral η1 carbide M6C precipitates distributed in Ni/Ni3B lamellar eutectic. Dry sliding wear tests suggested that the composite coating containing about 30vol-% WC particulates has the highest wear resistance..
Chinese Journal of Lasers
- Publication Date: Jan. 01, 1900
- Vol. 26, Issue 2, 186 (1999)
Laser Physics
A Unidirectional Nd:YAG Ring Laser Resonator with a Cr4+:YAG Passive Q-switch
[in Chinese], [in Chinese], [in Chinese], [in Chinese], and [in Chinese]
A unidirectional Nd:YAG ring laser resonator with an auxiliary mirror was introduced. Cr4+:YAG crystals were used as a saturable passive Q-switch. The ring resonator was designed and a sequence of Q-switch pulses using Cr4+:YAG crystals of different initial transparences were observed and analyzed.A unidirectional Nd:YAG ring laser resonator with an auxiliary mirror was introduced. Cr4+:YAG crystals were used as a saturable passive Q-switch. The ring resonator was designed and a sequence of Q-switch pulses using Cr4+:YAG crystals of different initial transparences were observed and analyzed..
Chinese Journal of Lasers
- Publication Date: Jan. 01, 1900
- Vol. 26, Issue 2, 97 (1999)
High Efficient CW Nd:SVAP Laser Operation at 1.06 μm and 1.34 μm Pumped by a Ti:sapphire Laser
[in Chinese], [in Chinese], [in Chinese], and [in Chinese]
High efficient CW Nd:SVAP laser operations at 1.06 μm and 1.34 μm are realized with a Ti:sapphire laser as the pump source. The threshold, slope efficiency, and maximum output power are 2 mW, 49.4%, and 336 mW at 1.06 μm, and 2.4 mW, 37.4%, and 165 mW at 1.34 μm respectively.High efficient CW Nd:SVAP laser operations at 1.06 μm and 1.34 μm are realized with a Ti:sapphire laser as the pump source. The threshold, slope efficiency, and maximum output power are 2 mW, 49.4%, and 336 mW at 1.06 μm, and 2.4 mW, 37.4%, and 165 mW at 1.34 μm respectively..
Chinese Journal of Lasers
- Publication Date: Jan. 01, 1900
- Vol. 26, Issue 2, 101 (1999)
Analysis of Fiber-coupled Laser-diode End-pumped Solid-state Lasers
[in Chinese], [in Chinese], [in Chinese], [in Chinese], and [in Chinese]
Two laser diodes simultaneously pump Nd:YAG through fiber-coupling. The relationship among the laser threshold, the output intensity profile and the pumping fields has been studied experimentally. It has been discovered that the threshold of the Nd:YAG laser can be lowered if the two laser diodes pump in sequence.Two laser diodes simultaneously pump Nd:YAG through fiber-coupling. The relationship among the laser threshold, the output intensity profile and the pumping fields has been studied experimentally. It has been discovered that the threshold of the Nd:YAG laser can be lowered if the two laser diodes pump in sequence..
Chinese Journal of Lasers
- Publication Date: Jan. 01, 1900
- Vol. 26, Issue 2, 105 (1999)
A 1.4～6 GHz Erbium Doped Fiber Laser Using the Rational Harmonic Mode-locking Technique
[in Chinese], [in Chinese], [in Chinese], [in Chinese], [in Chinese], [in Chinese], and [in Chinese]
We demonstrate rational harmonic mode-locking (RHML) in a very simple cavity Er-fiber ring laser. Using RHML the authors succeeded in otbaining the optical pulses at a repetition rate (fm) which is multiples of the RF drive frequency (fm≈1.4 GHz) with a detuning ratio of >10-6. The generation of the maximum frequencWe demonstrate rational harmonic mode-locking (RHML) in a very simple cavity Er-fiber ring laser. Using RHML the authors succeeded in otbaining the optical pulses at a repetition rate (fm) which is multiples of the RF drive frequency (fm≈1.4 GHz) with a detuning ratio of >10-6. The generation of the maximum frequency was about 6 GHz and the stable rational harmonic mode-locking occurs only at fb=2fm. The experiment shows that the RHML technique is feasible in a short and very simple cavity Er-fiber laser..
Chinese Journal of Lasers
- Publication Date: Jan. 01, 1900
- Vol. 26, Issue 2, 109 (1999)
Two-dimensional Six-gateway RF-discharge Waveguide CO2Laser Arrays
[in Chinese], [in Chinese], [in Chinese], and [in Chinese]
A new kind of two-dimensional RF-discharge waveguide CO2 laser arrays is reported. The characteristics of the laser arrays have been studied and the output power is 20 W when the gain length is 380 mm.A new kind of two-dimensional RF-discharge waveguide CO2 laser arrays is reported. The characteristics of the laser arrays have been studied and the output power is 20 W when the gain length is 380 mm..
Chinese Journal of Lasers
- Publication Date: Jan. 01, 1900
- Vol. 26, Issue 2, 113 (1999)
Dispersive Waves in a Kerr-lens Mode-locked Solitary Laser
[in Chinese], [in Chinese], and [in Chinese]
The generation of dispersive waves caused by multi higher-order dispersions in Kerr-lens mode-locked solitary lasers is investigated by soliton perturbation theory. Analytical expressions for resonant frequencies, temporal width and energy of dispersive waves are derived, which are in good agreement with experimental mThe generation of dispersive waves caused by multi higher-order dispersions in Kerr-lens mode-locked solitary lasers is investigated by soliton perturbation theory. Analytical expressions for resonant frequencies, temporal width and energy of dispersive waves are derived, which are in good agreement with experimental measurements. The results are important for intra-cavity dispersion management for improving the pulse quality and minimizing the pulse energy drain..
Chinese Journal of Lasers
- Publication Date: Jan. 01, 1900
- Vol. 26, Issue 2, 116 (1999)
Mass Spectrometric Study of CnN-mGenerated by the Reaction of a Laser Ablated Plume with a Nitrogen Ion Beam
[in Chinese], [in Chinese], [in Chinese], [in Chinese], [in Chinese], and [in Chinese]
Reaction of an atomic nitrogen ion beam with carbon clusters generated by pulsed laser ablation of graphite was studied by time-of-flight mass spectrometry. A series of CnN-m clusters were detected. The mechanism of the formation of the negative ions of the carbon-nitride clusters was discussed.Reaction of an atomic nitrogen ion beam with carbon clusters generated by pulsed laser ablation of graphite was studied by time-of-flight mass spectrometry. A series of CnN-m clusters were detected. The mechanism of the formation of the negative ions of the carbon-nitride clusters was discussed..
Chinese Journal of Lasers
- Publication Date: Jan. 01, 1900
- Vol. 26, Issue 2, 148 (1999)
Propagation of a Finite-diameter Light Beam in Biological Tissues
[in Chinese], [in Chinese], [in Chinese], and [in Chinese]
A Monte Carlo method is used to study light distribution in tissues as a finite diameter light illuminates tissues. The total diffuse reflectances and transmittances of tissues illuminated respectively with an infinite thin light beam, a Gaussian beam and a flat beam are simulated respectively. We also simulate finite A Monte Carlo method is used to study light distribution in tissues as a finite diameter light illuminates tissues. The total diffuse reflectances and transmittances of tissues illuminated respectively with an infinite thin light beam, a Gaussian beam and a flat beam are simulated respectively. We also simulate finite width light propagation in multi-layered tissues..
Chinese Journal of Lasers
- Publication Date: Jan. 01, 1900
- Vol. 26, Issue 2, 153 (1999)
Sum-frequency Action for Dual Wavelength Nd:YAP Laser in MgO:LiNbO3Crystal
[in Chinese], [in Chinese], and [in Chinese]
Based on Sellmeier equations for MgO:LiNbO3(Mg:LN) crystal, the phase-matched condition and acceptance angle for sum-frequency generation of a radiation at wavelengths of 1079.5 nm and 1341.4 nm have been calculated. The calculated results were verified by the sum-frequency generation in MgO:LiNbO3 crystal with a 1079.Based on Sellmeier equations for MgO:LiNbO3(Mg:LN) crystal, the phase-matched condition and acceptance angle for sum-frequency generation of a radiation at wavelengths of 1079.5 nm and 1341.4 nm have been calculated. The calculated results were verified by the sum-frequency generation in MgO:LiNbO3 crystal with a 1079.5 nm and 1341.4 nm dual wavelength Nd:YAlO3 (Nd:YAP) CW laser. A CW coherent orange radiation at wavelength of 598.1 nm has been achieved. The possibility to obtain the 588.7 nm coherent orange radiation using a 1064 nm and 1318 nm dual wavelength Nd:YAG laser in MgO:LiNbO3 crystal was also discussed..
Chinese Journal of Lasers
- Publication Date: Jan. 01, 1900
- Vol. 26, Issue 2, 159 (1999)
Numerical Studies on Collisions of Orthogonally Polarized Solitons in Birefringent Optical Fibers
[in Chinese], and [in Chinese]
A set of nonlinear coupled equations describing the propagation of picosecond pulses in linearly birefringent optical fibers are derived from the Maxwell equations in the frequency domain. The numerical approach is given, then the collisions of orthogonally polarized fundamental solitons in birefringent fibers are inveA set of nonlinear coupled equations describing the propagation of picosecond pulses in linearly birefringent optical fibers are derived from the Maxwell equations in the frequency domain. The numerical approach is given, then the collisions of orthogonally polarized fundamental solitons in birefringent fibers are investigated numerically. The effect of initial separation of the two solitons on the soliton collisions is analyzed. In addition, a transition region between trap and separate region is also found. The collisions in the transition region are resonant..
Chinese Journal of Lasers
- Publication Date: Jan. 01, 1900
- Vol. 26, Issue 2, 163 (1999)
A Decentered Elliptical Gaussian Beam
[in Chinese], [in Chinese], [in Chinese], and [in Chinese]
The generalization of an elliptical Gaussian beam is presented by introducing a complex shift in the transverse coordinates. The intensity distribution of the resulting beam is a Gaussian function distribution with the width varying as an ordinary elliptical Gaussian beam in the plane perpendicular to z axis, the peak The generalization of an elliptical Gaussian beam is presented by introducing a complex shift in the transverse coordinates. The intensity distribution of the resulting beam is a Gaussian function distribution with the width varying as an ordinary elliptical Gaussian beam in the plane perpendicular to z axis, the peak intensity of which traces a linear trajactory. The wave fronts are displaced laterally. The beam is referred to as a decentered elliptical Gaussian beam, its transformation is deduced quantitatively when passing through an optical system..
Chinese Journal of Lasers
- Publication Date: Jan. 01, 1900
- Vol. 26, Issue 2, 171 (1999)
Resonance Enhanced Multiphoton Ionization Mass Spectra of C2H5I
[in Chinese], [in Chinese], [in Chinese], [in Chinese], [in Chinese], [in Chinese], and [in Chinese]
The multiphoton ionization spectra of ethyl iodide are obtained by a time-of-flight mass spectrometer in the 473～483 nm region. It is found that parent molecules are firstly 2-photon resonantly excited to intermediate states of 3E, 2A1 and 1A2 in the A-band, and then dissociated. C2H+5 and I+ ions are produced by ionizThe multiphoton ionization spectra of ethyl iodide are obtained by a time-of-flight mass spectrometer in the 473～483 nm region. It is found that parent molecules are firstly 2-photon resonantly excited to intermediate states of 3E, 2A1 and 1A2 in the A-band, and then dissociated. C2H+5 and I+ ions are produced by ionization of the neutral fragments. C2H+5 ions dissociate to a certain degree when absorbing photons further..
Chinese Journal of Lasers
- Publication Date: Jan. 01, 1900
- Vol. 26, Issue 2, 176 (1999)
Materials and Thin Films
Picosecond Infrared Laser Stimulated Luminescence in Electron Trapping Materials
[in Chinese], [in Chinese], [in Chinese], [in Chinese], [in Chinese], [in Chinese], and [in Chinese]
By projecting double pulses on the photocathode of a streak camera, the optically stimulated luminescence (OSL) from electron trapping materials such as CaS:Eu, and Sm, stimulated with a single 19.2 ps pulse (FWHM), is shown to occur with response and decays within less than 14.3 ps (FWHM). The two phosphors investigatBy projecting double pulses on the photocathode of a streak camera, the optically stimulated luminescence (OSL) from electron trapping materials such as CaS:Eu, and Sm, stimulated with a single 19.2 ps pulse (FWHM), is shown to occur with response and decays within less than 14.3 ps (FWHM). The two phosphors investigated are efficiently stimulated with 1.064 μm photons from a pulsed Nd:yttrium aluminum garnet (YAG) laser. By analysing and discussing the result, it is shown that this kind of novel materials may be used in the rapid infrared up-conversion and related fields..
Chinese Journal of Lasers
- Publication Date: Jan. 01, 1900
- Vol. 26, Issue 2, 181 (1999)
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