Journals >Chinese Journal of Lasers
Contents
2000
Volume: 27 Issue 11
20 Article(s)
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Research Article
Mode of Resonators with Spatial-temporal Phase Modulation
[in Chinese], [in Chinese], and [in Chinese]
A kind of resonator with spatial-temporal phase modulation is proposed. The modes of this kind of resonator are analyzed and calculated numerically in terms of the modal theory of coherence in space-time domain. The results show that the modes are completely coherent under fixed phase modulation on one mirror of resonaA kind of resonator with spatial-temporal phase modulation is proposed. The modes of this kind of resonator are analyzed and calculated numerically in terms of the modal theory of coherence in space-time domain. The results show that the modes are completely coherent under fixed phase modulation on one mirror of resonator. There is a suitable value of resonator parameter to obtain flat-top beam on one mirror. For resonators with random disturbed phase mirror, its modes are partially coherent, and there also exists a suitable parameter to get flat-top beam..
Chinese Journal of Lasers
- Publication Date: Jan. 01, 1900
- Vol. 27, Issue 11, 997 (2000)
Research on the Simultaneous Measurements of Pressure and Temperature Using One Fiber Grating
[in Chinese], [in Chinese], [in Chinese], [in Chinese], [in Chinese], and [in Chinese]
The small volume fiber Bragg grating (FBG) sensor head designed by using especial package technique with polymer material has the function of simultaneous measurements of pressure and temperature, which can solve the temperature cross-sensitivity of FBG effectively. Simultaneous measurements of the pressure and temperaThe small volume fiber Bragg grating (FBG) sensor head designed by using especial package technique with polymer material has the function of simultaneous measurements of pressure and temperature, which can solve the temperature cross-sensitivity of FBG effectively. Simultaneous measurements of the pressure and temperature using only one grating based on the two reflective peaks with different pressure and temperature sensitivity coefficients through the process of packaging FBG are demonstrated..
Chinese Journal of Lasers
- Publication Date: Jan. 01, 1900
- Vol. 27, Issue 11, 1002 (2000)
An Experimental Research to Objectively Test the Resolving Power of Films
[in Chinese], [in Chinese], and [in Chinese]
A criterion to determine the limiting resolving power of film by using Fourier power spectrum is proposed in this paper. It is an objective evaluation method, in which the Fourier frequency spectra of the resolving power of film are analyzed and processed according to the optical information processing principle. The sA criterion to determine the limiting resolving power of film by using Fourier power spectrum is proposed in this paper. It is an objective evaluation method, in which the Fourier frequency spectra of the resolving power of film are analyzed and processed according to the optical information processing principle. The scale to objectively testing the resolving power of film is derived through analysis of the Fourier power spectrum critical maximum coordinates of the film. The similar linear relations between the resolving power of the film and the critical maximum are defined..
Chinese Journal of Lasers
- Publication Date: Jan. 01, 1900
- Vol. 27, Issue 11, 1007 (2000)
Experimental Study of Spot Dancing of Laser Beam in a Turbulent Atmosphere
[in Chinese], [in Chinese], [in Chinese], and [in Chinese]
The spot dancing of laser beam in a turbulent atmosphere was studied experimentally with a detector array system. The system has advantages over the imaging system, i.e., wide dynamic range and high sampling rate. The results of groud-based transmission experiments show that the spot dancing is a little larger in the vThe spot dancing of laser beam in a turbulent atmosphere was studied experimentally with a detector array system. The system has advantages over the imaging system, i.e., wide dynamic range and high sampling rate. The results of groud-based transmission experiments show that the spot dancing is a little larger in the vertical direction than in the horizontal direction. Under strong turbulence condition in clear weather the spot dancing coincides quantitatively with theoretical prediction, and its time variation is similar to that of the light scintillation, but they can be much different from each other under other conditions. Up to one thousand hertz the power spectrum of the spot dancing can be well fitted by power laws in three frequency ranges, and the exponents are about -1.2, -2.4, and -4.8 respectively..
Chinese Journal of Lasers
- Publication Date: Jan. 01, 1900
- Vol. 27, Issue 11, 1011 (2000)
Study on 18～20 nm Broadband Multilayer at Normal Incidence
[in Chinese], [in Chinese], [in Chinese], and [in Chinese]
In this paper, a better random method used for improving the light integrated reflectance in the 18～20 nm spectral region of a soft X-ray multilayer has been developed, a 8% increase in reflectance is obtained. The multilayer is fabricated by magnetron sputtering. The reflectance comparative measurement are used for teIn this paper, a better random method used for improving the light integrated reflectance in the 18～20 nm spectral region of a soft X-ray multilayer has been developed, a 8% increase in reflectance is obtained. The multilayer is fabricated by magnetron sputtering. The reflectance comparative measurement are used for testing the multilayer. The results demonstrate that the layer thickness disorder yields band broadening and wider view field with respect to periodic multilayer, but accompanied with a reduction in reflectance peak. Techniques of control layer thickness is the keystone of experiment..
Chinese Journal of Lasers
- Publication Date: Jan. 01, 1900
- Vol. 27, Issue 11, 1016 (2000)
Holography and Information Processing
155 Mbits/s Atmospheric Optical Communication System and Its Measurement
[in Chinese], [in Chinese], [in Chinese], [in Chinese], and [in Chinese]
Atmospheric optical communication system with fiber in and fiber out is developed. It is in the lead domestic that communication rate is 155 Mbits/s and availability distance is 2 km. Design consideration, basic principle and system architecture of atmospheric optical communication system are demonstrated. Experiment rAtmospheric optical communication system with fiber in and fiber out is developed. It is in the lead domestic that communication rate is 155 Mbits/s and availability distance is 2 km. Design consideration, basic principle and system architecture of atmospheric optical communication system are demonstrated. Experiment result outdoors is analyzed, and the system′s practicability is mentioned..
Chinese Journal of Lasers
- Publication Date: Jan. 01, 1900
- Vol. 27, Issue 11, 1040 (2000)
Laser Manufacturing
Investigation of Optimized Cutting Conditions of Al2O3 Ceramic Plate by Pulsed CO2 Laser
[in Chinese], [in Chinese], [in Chinese], and [in Chinese]
This article investigates the influence of the factors such as frequency of CO2 laser pulses, laser average power and the pressure of assistant air on the quality of cutting. The optimized conditions to cut ceramics for example Al2O3 are discussed.This article investigates the influence of the factors such as frequency of CO2 laser pulses, laser average power and the pressure of assistant air on the quality of cutting. The optimized conditions to cut ceramics for example Al2O3 are discussed..
Chinese Journal of Lasers
- Publication Date: Jan. 01, 1900
- Vol. 27, Issue 11, 1045 (2000)
Parameters and Mechanisms of Laser Cleaning Rubber Layer on a Tyre Mould
[in Chinese], [in Chinese], and [in Chinese]
This report presented a detailed study on parameters and mechanisms of cleaning rubber layer from a tyre wording mould with pulse laser. The results demonstrated that pulse laser can remove rubber layer completely under proper parameters. There exist cleaning threshold and damage threshold in laser cleaning. Between thThis report presented a detailed study on parameters and mechanisms of cleaning rubber layer from a tyre wording mould with pulse laser. The results demonstrated that pulse laser can remove rubber layer completely under proper parameters. There exist cleaning threshold and damage threshold in laser cleaning. Between the initial cleaning threshold and complete cleaning threshold, cleaning percentage of the surface increases with the increasing of laser fluence. When the laser fluences are between complete cleaning threshold and damage threshold, cleaning percentage keeps up 100% and no damage is found on substrate surface. Two mechanisms for laser cleaning rubber layer are suggested: one is the combustion and vaporation of upper rubber layer resulted by high temperature of laser beam, the other is the vibration of deep rubber layer as well as thermal shock action by laser pulse to make rubber particles sputter..
Chinese Journal of Lasers
- Publication Date: Jan. 01, 1900
- Vol. 27, Issue 11, 1050 (2000)
Laser Physics
Study of RF Excited Waveguide CO2 Laser with Two Channels Tuned by Grating
[in Chinese], [in Chinese], [in Chinese], [in Chinese], and [in Chinese]
RF excited waveguide CO2 laser with two-channels tuned by grating is present. The direction of laser from the two channels is opposited. The offset frequency stability of short term can be up to the order of 10-9 without any measures to stabilize the frequency being taken. The offset frequency deviation in a minute is RF excited waveguide CO2 laser with two-channels tuned by grating is present. The direction of laser from the two channels is opposited. The offset frequency stability of short term can be up to the order of 10-9 without any measures to stabilize the frequency being taken. The offset frequency deviation in a minute is less than 2 MHz..
Chinese Journal of Lasers
- Publication Date: Jan. 01, 1900
- Vol. 27, Issue 11, 961 (2000)
Experiment Research of 200 Hz Repetition Rate Q-switched TEM00-mode Nd:YAG Laser Side-pumped by Laser Diode Array
[in Chinese], [in Chinese], [in Chinese], [in Chinese], and [in Chinese]
A laser diode array side-pumped high repetition rate, Q-switched, TEM00- mode Nd:YAG laser is reported. With about 270 mJ pump energy, an energy of 29.7 mJ, pulse width of 6.4 ns TEM00-mode laser output at 200 Hz repetition rate is obtained, slope efficiency is about 16.5%. By using a KTP as a frequency-doubling crystaA laser diode array side-pumped high repetition rate, Q-switched, TEM00- mode Nd:YAG laser is reported. With about 270 mJ pump energy, an energy of 29.7 mJ, pulse width of 6.4 ns TEM00-mode laser output at 200 Hz repetition rate is obtained, slope efficiency is about 16.5%. By using a KTP as a frequency-doubling crystal, an energy of 16.8 mJ, pulse width of 5.6 ns green output is achieved, optical-optical efficiency is 56.6%..
Chinese Journal of Lasers
- Publication Date: Jan. 01, 1900
- Vol. 27, Issue 11, 965 (2000)
Study on Photothermal Intensity-modulation Characteristics of Laser-diode
[in Chinese], [in Chinese], [in Chinese], [in Chinese], [in Chinese], [in Chinese], and [in Chinese]
Based on the physical model of a laser diode (LD) modulated utilizing photothermal effect, the relations of the photothermal intensity-modulation depth of the LD with the modulation frequency and injection current are theoretically and verify experimentally deduced. It is useful for determining appropriate modulation fBased on the physical model of a laser diode (LD) modulated utilizing photothermal effect, the relations of the photothermal intensity-modulation depth of the LD with the modulation frequency and injection current are theoretically and verify experimentally deduced. It is useful for determining appropriate modulation frequency and injection current in LD interferometer with a photothermal modulation to reduce the influence of light-intensity modulation and realize nanometer-accuracy interferometer measurement..
Chinese Journal of Lasers
- Publication Date: Jan. 01, 1900
- Vol. 27, Issue 11, 969 (2000)
Experimental Study of Low-frequency Voltage Wavelength Modulation and Harmonic Detection Using an External-cavity Diode Laser
[in Chinese], [in Chinese], [in Chinese], [in Chinese], and [in Chinese]
A low-frequency wavelength modulation spectroscopy is acquired with an external-cavity tunable diode laser. The wavelength modulation is achieved using the voltage tuning by scanning the piezoelectric stepper motor with rotating of the end mirror in the laser cavity. With optimum modulation frequency of 1-kHz a harmoniA low-frequency wavelength modulation spectroscopy is acquired with an external-cavity tunable diode laser. The wavelength modulation is achieved using the voltage tuning by scanning the piezoelectric stepper motor with rotating of the end mirror in the laser cavity. With optimum modulation frequency of 1-kHz a harmonic detection processed by a lock-in amplifier for cesium D2 line was carried out. It is found that 6f-harmonic detection is best here with the signal-to-noise voltage ratio (SNR) being 460. It is also shown that nearly overlapping lines may be better resolved by using 6f harmonic detection due to the much less modulation-broadened spectra..
Chinese Journal of Lasers
- Publication Date: Jan. 01, 1900
- Vol. 27, Issue 11, 973 (2000)
Relation between Q-switch Effect and Primary Resonator Stability in Phase Conjugation Laser Based on SBS
[in Chinese], [in Chinese], [in Chinese], [in Chinese], [in Chinese], and [in Chinese]
In this paper, the influence of the primary resonator′s stability on the Q-switch is experimentally studied, the results have shown that unstable primary resonator with high diffraction losses can improve the Q-switch effect of phase conjugation cavity laser. The characteristic of output pulses from two types of phase In this paper, the influence of the primary resonator′s stability on the Q-switch is experimentally studied, the results have shown that unstable primary resonator with high diffraction losses can improve the Q-switch effect of phase conjugation cavity laser. The characteristic of output pulses from two types of phase conjugation cavity lasers with H2O and CS2 SBS medium, was compared and analyzed..
Chinese Journal of Lasers
- Publication Date: Jan. 01, 1900
- Vol. 27, Issue 11, 978 (2000)
Multiwavelength and Ultra-short Pulses Actively Mode-locked Fiber Laser
[in Chinese], [in Chinese], [in Chinese], and [in Chinese]
By using a dispersion compensation fiber (DCF) to increase the cavity dispersion, an actively mode-locked fiber ring laser with an output pulse at repetition rate 10 GHz and 8 wavelengths (19 wavelengths) in the experiment was obtained.By using a dispersion compensation fiber (DCF) to increase the cavity dispersion, an actively mode-locked fiber ring laser with an output pulse at repetition rate 10 GHz and 8 wavelengths (19 wavelengths) in the experiment was obtained..
Chinese Journal of Lasers
- Publication Date: Jan. 01, 1900
- Vol. 27, Issue 11, 983 (2000)
Fabrication and Lasing Properties of Yb3+-doped Double-clad Silica Fiber
[in Chinese], [in Chinese], [in Chinese], [in Chinese], [in Chinese], [in Chinese], [in Chinese], [in Chinese], [in Chinese], [in Chinese], and [in Chinese]
Yb3+-doped double-clad silica fiber with large geometry and numerical aperture was developed by using MCVD process and solution-doping technique. The diameter and numerical aperture of inner cladding are 125 μm and 0.36, respectively. The preliminary experiment of the clad-pumped fiber laser has been accomplished. The Yb3+-doped double-clad silica fiber with large geometry and numerical aperture was developed by using MCVD process and solution-doping technique. The diameter and numerical aperture of inner cladding are 125 μm and 0.36, respectively. The preliminary experiment of the clad-pumped fiber laser has been accomplished. The output power from laser is 220 mW at 1.06 μm, and optical conversion efficiency is 26%..
Chinese Journal of Lasers
- Publication Date: Jan. 01, 1900
- Vol. 27, Issue 11, 987 (2000)
Tunable Eye-safe Laser Based on KTP Optical Parametric Oscillator
[in Chinese], [in Chinese], [in Chinese], [in Chinese], [in Chinese], and [in Chinese]
The experimental results of singly resonant KTP optical parametric oscillator pumped by second harmonic of GCR-190 Nd:YAG laser system are reported in this paper. The KTP OPO was tunable in the eye-safe wavelengths range of 1.53～1.84 μm and 0.75～0.82 μm in the near-infared region. In this experiment, the largest energyThe experimental results of singly resonant KTP optical parametric oscillator pumped by second harmonic of GCR-190 Nd:YAG laser system are reported in this paper. The KTP OPO was tunable in the eye-safe wavelengths range of 1.53～1.84 μm and 0.75～0.82 μm in the near-infared region. In this experiment, the largest energy of 130 mJ and highest energy conversion efficiency of 16.9% with repetition rate of 10 Hz were achieved, while the pump laser was introduced into the oscillator along the direction vertical to cavity axis. At the same time, the beam quality and linewidth of KTP OPO were measured..
Chinese Journal of Lasers
- Publication Date: Jan. 01, 1900
- Vol. 27, Issue 11, 992 (2000)
Effects of the Noise-correlation-time of a Single-mode Laser
[in Chinese], [in Chinese], [in Chinese], and [in Chinese]
By means of linear approximation method, the intensity correlation function, correlation time and power spectrum for the gain-noise model of a single-mode laser driven by correlated noises are derived. Effects of mutual-correlation-time and self-correlation-time for the noise on the above-mentioned properties of the laBy means of linear approximation method, the intensity correlation function, correlation time and power spectrum for the gain-noise model of a single-mode laser driven by correlated noises are derived. Effects of mutual-correlation-time and self-correlation-time for the noise on the above-mentioned properties of the laser are analysed and discussed. It is found that, in a single-mode laser system driven by correlated noises, effects of two noise-correlation-time on statistical properties of the laser are quite different. Some novel phenomena are obtained..
Chinese Journal of Lasers
- Publication Date: Jan. 01, 1900
- Vol. 27, Issue 11, 1019 (2000)
Limitation of the Scale Factor in the Optical-wavelet Transformation
[in Chinese]
In this paper, the limitation for choosing the scale factor of an optical system in an optical-wavelet transformation is analysed; a minimal scale factor of an optical system is determined in corresponding to an optical-wavelet transformation; and the minima of scale factor in a 4F optical processor are calculated for In this paper, the limitation for choosing the scale factor of an optical system in an optical-wavelet transformation is analysed; a minimal scale factor of an optical system is determined in corresponding to an optical-wavelet transformation; and the minima of scale factor in a 4F optical processor are calculated for the transformation with a few of specified wavelet functions, some significant data are provided for the application for wavelet transformation in real optical information processor..
Chinese Journal of Lasers
- Publication Date: Jan. 01, 1900
- Vol. 27, Issue 11, 1025 (2000)
Materials and Thin Films
Investigation of Laser Damage of BaF2Crystal
[in Chinese], [in Chinese], and [in Chinese]
Laser damage and strengthened laser damage shrength of BaF2 crystals are investigated by short pulse, long pulse and continuous lasers. Laser damage thresholds, damage morphologies and effects of strengthened are reported with different experiment conditions. The mechnisms of laser damage and strengthened laser damage Laser damage and strengthened laser damage shrength of BaF2 crystals are investigated by short pulse, long pulse and continuous lasers. Laser damage thresholds, damage morphologies and effects of strengthened are reported with different experiment conditions. The mechnisms of laser damage and strengthened laser damage strength are analyzed..
Chinese Journal of Lasers
- Publication Date: Jan. 01, 1900
- Vol. 27, Issue 11, 1029 (2000)
Formation and Removal Processing of Platinum Inclusions in Phosphate Laser Glass
[in Chinese], [in Chinese], and [in Chinese]
The calculated values of the formation enthalpy, ΔH2980, and the free energy of formation, ΔG2980, of platinum compounds and some related phosphate or metaphosphate compounds in phosphate laser glass were given based on the thermodynamic and electrochemisty methods in the present paper. Using the parameters mentioned aThe calculated values of the formation enthalpy, ΔH2980, and the free energy of formation, ΔG2980, of platinum compounds and some related phosphate or metaphosphate compounds in phosphate laser glass were given based on the thermodynamic and electrochemisty methods in the present paper. Using the parameters mentioned above, the direction and limitation of chemical reaction between liquid and solid, gas and solid, or gas and liquid that can possibly exist in phosphate laser glass during the melting process were studied. Finally, the mechanism of eliminating platinum inclusions in phosphate laser glass by POCl3 gas bubbling and the optimum process were discussed from thermodynamics aspect..
Chinese Journal of Lasers
- Publication Date: Jan. 01, 1900
- Vol. 27, Issue 11, 1035 (2000)
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