Journals >Chinese Journal of Lasers
Contents
2000
Volume: 27 Issue 1
20 Article(s)
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Research Article
A Highly Sensitive Doppler Limited Photoacoustic Overtone Spectrometer with a Ti:sapphire Ring Laser—Optical Multipass and Acoustic Resonance
[in Chinese], [in Chinese], [in Chinese], [in Chinese], and [in Chinese]
The factors, especially the photoacoustic cell′s size, which have effects on the amplitude of the photoacoustic signal, are analysized. When a multipass cylindrical cell with optimal dimensions is operated in the first-order radial resonance mode, the signal-to-noise ratio of photoacoustic signal can be greatly improveThe factors, especially the photoacoustic cell′s size, which have effects on the amplitude of the photoacoustic signal, are analysized. When a multipass cylindrical cell with optimal dimensions is operated in the first-order radial resonance mode, the signal-to-noise ratio of photoacoustic signal can be greatly improved. Using a Ti:sapphire ring laser as the light source, a laser photoacoustic spectrometer reaching a sensitivity of 8.5×10-9 cm-1 (SNR=1:1) is realized; then the sixth stretching overtone spectrum of AsH3 was first recorded with this instrument..
Chinese Journal of Lasers
- Publication Date: Jan. 01, 1900
- Vol. 27, Issue 1, 16 (2000)
Design Principle of the Free-vortex Aerodynamic Window and an Experimental Study on Its Running Properties
[in Chinese], [in Chinese], [in Chinese], [in Chinese], [in Chinese], and [in Chinese]
The principle of the free-vortex aerodynamic window (FADW) is described. The sealing property and influence of a FADW device designed for the 10 kW CO2 gas dynamic laser (GDL) on the optical quality have been studied experimentally. The experimental results show that this FADW device can attain a high sealing-pressure The principle of the free-vortex aerodynamic window (FADW) is described. The sealing property and influence of a FADW device designed for the 10 kW CO2 gas dynamic laser (GDL) on the optical quality have been studied experimentally. The experimental results show that this FADW device can attain a high sealing-pressure ratio PR>20, with the highest being 28 under the designing conditions, and that the FADW has a good starting-property and little influence on the optical quality. So this kind of free-vortex aerodynamic window is a promising alternative to take the place of the crystal windows..
Chinese Journal of Lasers
- Publication Date: Jan. 01, 1900
- Vol. 27, Issue 1, 23 (2000)
Geometric Symmetry of the Laser Beam′s Arrangement Scheme on the Surface of a Ball Target
[in Chinese], [in Chinese], [in Chinese], [in Chinese], [in Chinese], and [in Chinese]
A computation method of longitudes and latitudes of incident windows for the 60 laser beams on the spherical target charmber is reported. It is shown analytically that when the length ratio between the neighboring sides of hexagonal faces on the 32-face polyhedron inscribed in the chamber′s spherical faces equals 1.14～A computation method of longitudes and latitudes of incident windows for the 60 laser beams on the spherical target charmber is reported. It is shown analytically that when the length ratio between the neighboring sides of hexagonal faces on the 32-face polyhedron inscribed in the chamber′s spherical faces equals 1.14～1.25, according to the criterion of irradiation uniformity on target for the “stretched soccer ball” model, the geometrical symmetry of the spatial arrangement of the beams comes to the optimum condition, and thus the irradiation uniformity of direct drive is improved..
Chinese Journal of Lasers
- Publication Date: Jan. 01, 1900
- Vol. 27, Issue 1, 28 (2000)
Fabrication of Thulium-doped Silica Optical Fibers
[in Chinese], [in Chinese], [in Chinese], [in Chinese], [in Chinese], [in Chinese], [in Chinese], and [in Chinese]
The preparation of silica optical fibers doped with rare earth ion Tm3+utilizing a solution-doped technique and the control of relevant parameters of the fibers are described. The control and the measurement method of the doping concentration of Tm3+have also been discussed.The preparation of silica optical fibers doped with rare earth ion Tm3+utilizing a solution-doped technique and the control of relevant parameters of the fibers are described. The control and the measurement method of the doping concentration of Tm3+have also been discussed..
Chinese Journal of Lasers
- Publication Date: Jan. 01, 1900
- Vol. 27, Issue 1, 33 (2000)
Numerical Study of Apodization Profile Functions and Optimal Profiles and Lengths of a Linearly Chirped Fiber Bragg Grating
[in Chinese], [in Chinese], [in Chinese], [in Chinese], [in Chinese], [in Chinese], [in Chinese], [in Chinese], and [in Chinese]
Starting from our defined apdization profile functions, the optimal profiles and the characteristics of a defined function in sidelobe suppression were found. In a specific instance, it is shown by a numerical analysis that the optimal length of a grating is 45 mm to compensate the dispersion induced by an 85 km-fiber.Starting from our defined apdization profile functions, the optimal profiles and the characteristics of a defined function in sidelobe suppression were found. In a specific instance, it is shown by a numerical analysis that the optimal length of a grating is 45 mm to compensate the dispersion induced by an 85 km-fiber..
Chinese Journal of Lasers
- Publication Date: Jan. 01, 1900
- Vol. 27, Issue 1, 37 (2000)
Holography and Information Processing
Experimental Study of 140 Mbit/s All-optical Wavelength Conversion
[in Chinese], [in Chinese], [in Chinese], [in Chinese], [in Chinese], and [in Chinese]
The wavelength conversion based on cross-gain modulation in a semiconductor optical amplifier (SOA) has been experimentally studied. The wavelength conversion is achieved between the wavelengths of 1.3152 μm and 1.3014 μm with a bit-rate of 140 Mbit/s, and the experimental results are explained.The wavelength conversion based on cross-gain modulation in a semiconductor optical amplifier (SOA) has been experimentally studied. The wavelength conversion is achieved between the wavelengths of 1.3152 μm and 1.3014 μm with a bit-rate of 140 Mbit/s, and the experimental results are explained..
Chinese Journal of Lasers
- Publication Date: Jan. 01, 1900
- Vol. 27, Issue 1, 69 (2000)
Readout of Grating Enhancement in Holographic Storage
[in Chinese], [in Chinese], [in Chinese], [in Chinese], [in Chinese], [in Chinese], and [in Chinese]
The spatial distribution function of grating amplitude recorded in photorefractive crystal based on the couple-waves theory is given. The enhancement properties of holographic grating readout by single-beam and by double-side alternative readout are analyzed after solving the couple-equations numerically. A storage arcThe spatial distribution function of grating amplitude recorded in photorefractive crystal based on the couple-waves theory is given. The enhancement properties of holographic grating readout by single-beam and by double-side alternative readout are analyzed after solving the couple-equations numerically. A storage architecture, which includes one crystal and a dynamic holographic refresher (DHR) easily enhanced diffraction efficiency by double-side readout is presented. Meanwhile the optimal architecture parameters to realize the grating enhancement are also given..
Chinese Journal of Lasers
- Publication Date: Jan. 01, 1900
- Vol. 27, Issue 1, 74 (2000)
Optical Wavelet Transform of Diffusion-limited Aggregate Pattern
[in Chinese], [in Chinese], [in Chinese], [in Chinese], and [in Chinese]
The method of realizing optical wavelet transform (OWT) with Mexican-hat wavelet function for diffusion-limited aggregate (DLA) pattern is described in this paper. DLA fractal pattern is successfully dissolved into different scale patterns by using a series of discrete dilation factor. The advantage of optical wavelet The method of realizing optical wavelet transform (OWT) with Mexican-hat wavelet function for diffusion-limited aggregate (DLA) pattern is described in this paper. DLA fractal pattern is successfully dissolved into different scale patterns by using a series of discrete dilation factor. The advantage of optical wavelet transform (OWT) is that the constructing process of self-similarity in fractal pattern can be observed simply and rapidly from the domain of different time. DLA Fractal dimension has been also obtained using the method of the OWT in this paper. The experimental results have proved that OWT is an important method to analyze DLA pattern in real time..
Chinese Journal of Lasers
- Publication Date: Jan. 01, 1900
- Vol. 27, Issue 1, 79 (2000)
Optical Coherent Tomography about Lotus Root
[in Chinese], [in Chinese], [in Chinese], [in Chinese], [in Chinese], and [in Chinese]
The longitudinal section image of a sample which is a part of the lotus root was obtained by an OCT system which is made of a fiber optical Michelson interferometer, a super luminent diode, the coherent length of which is only 25 μm, as the source, a photomultiplizer tube and a lock-in amplifier as the detection schemeThe longitudinal section image of a sample which is a part of the lotus root was obtained by an OCT system which is made of a fiber optical Michelson interferometer, a super luminent diode, the coherent length of which is only 25 μm, as the source, a photomultiplizer tube and a lock-in amplifier as the detection scheme. The system′s detection sensitivity is 90 dB..
Chinese Journal of Lasers
- Publication Date: Jan. 01, 1900
- Vol. 27, Issue 1, 83 (2000)
PS Optical Interconnection Realized by Virtual Focus Imaging under the Parallel Light Input
[in Chinese], [in Chinese], and [in Chinese]
Using a 2×2 holographic lens array and a virtual focus imaging method, PS optical interconnection of the 2D elements group is realized under the parallel light input. The virtual focus imaging PS transformation of 2N×2N input element group is directly realized by the lens array. The imaging magnifying power iUsing a 2×2 holographic lens array and a virtual focus imaging method, PS optical interconnection of the 2D elements group is realized under the parallel light input. The virtual focus imaging PS transformation of 2N×2N input element group is directly realized by the lens array. The imaging magnifying power is 2N and the imaging distance lH varies linearly with N. When an imaging lens L is inserted behind the lens array, the deduced formulas of imaging distance relate mainly to the focal length and the imaging magnifying power relates mainly to the ratio between the imaging lens focal length and the holographic lens focal length. The experiments prove correctness of the formulas..
Chinese Journal of Lasers
- Publication Date: Jan. 01, 1900
- Vol. 27, Issue 1, 87 (2000)
Laser Manufacturing
High Current Density YBCO Superconducting Tape on Stainless Steel Substrates
[in Chinese], [in Chinese], [in Chinese], and [in Chinese]
The (002) directional Yttria-Stabilized Zirconia (YSZ) buffered layer film was deposited on the stainless steel substrate with the Ar+ ion beam assistence at room temperature,and then the YBa2Cu3O7-x (YBCO) film was deposited on the YSZ/stainless steel substrate at 750℃ by pulsed laser ablation. The experimental resultThe (002) directional Yttria-Stabilized Zirconia (YSZ) buffered layer film was deposited on the stainless steel substrate with the Ar+ ion beam assistence at room temperature,and then the YBa2Cu3O7-x (YBCO) film was deposited on the YSZ/stainless steel substrate at 750℃ by pulsed laser ablation. The experimental results show that the critical temperature and the critical current density of the YBCO superconducting film are 91 K (R=0) and 1.2×106 A/cm2 (77 K, 0 T) respectively..
Chinese Journal of Lasers
- Publication Date: Jan. 01, 1900
- Vol. 27, Issue 1, 91 (2000)
Photodynamic Therapy of Malignancy of Skin with a He-Ne Laser
[in Chinese], [in Chinese], and [in Chinese]
35 cases of skin malignancy treated with photodynamic therapy were reported. A He-Ne laser with an output power of 600 mW and the hematoporphyrin derivative were applied. After the follow-up of 3 to 9 months, the results showed that the cure rate is 91.43% (32 cases) and the effective rate is 8.57% (3 cases).35 cases of skin malignancy treated with photodynamic therapy were reported. A He-Ne laser with an output power of 600 mW and the hematoporphyrin derivative were applied. After the follow-up of 3 to 9 months, the results showed that the cure rate is 91.43% (32 cases) and the effective rate is 8.57% (3 cases)..
Chinese Journal of Lasers
- Publication Date: Jan. 01, 1900
- Vol. 27, Issue 1, 95 (2000)
Laser Physics
Theory and Analysis of Laser Diode End-pumped Nd:Ti:LiNbO3Waveguide Laser
[in Chinese], [in Chinese], [in Chinese], and [in Chinese]
Based upon a beam propagation method, a model of 1.084 μm Nd:Ti:LiNbO3 waveguide laser end-pumped by a laser diode has been proposed in this paper. The laser gain and pump absorption were described through the complex atomic susceptibility of Nd3+ ions. By using a diode laser as the pump source, the interference effectBased upon a beam propagation method, a model of 1.084 μm Nd:Ti:LiNbO3 waveguide laser end-pumped by a laser diode has been proposed in this paper. The laser gain and pump absorption were described through the complex atomic susceptibility of Nd3+ ions. By using a diode laser as the pump source, the interference effect between the forward and the backward light waves was considered and the population inversion spatial effect was given. Moreover, the values of absorption and emission cross section were modified. A good correspondence can be got between the theoretical and experimental values..
Chinese Journal of Lasers
- Publication Date: Jan. 01, 1900
- Vol. 27, Issue 1, 1 (2000)
Design of Resonators for High-power Laser Diode End-pumped CW Solid-state Lasers
[in Chinese], [in Chinese], [in Chinese], [in Chinese], and [in Chinese]
A few critical rules concerning the design of resonators used for high-power laser diode end-pumped CW solid-state lasers were presented in this paper. Following these rules and utilizing a numerical computation procedure, it is possible to find out optimal cavity configurations characteristic of a wide range of thermaA few critical rules concerning the design of resonators used for high-power laser diode end-pumped CW solid-state lasers were presented in this paper. Following these rules and utilizing a numerical computation procedure, it is possible to find out optimal cavity configurations characteristic of a wide range of thermal stability, a fundamental mode radius within the laser medium which is independent of thermal lensing, being free from astigmatism in the whole cavity and being far away from the edge of the stability region in the range of pump power of interest. Experimental results show that the lasers based on such a resonator can readily be operated with low threshold pump power, high output power and high efficiency..
Chinese Journal of Lasers
- Publication Date: Jan. 01, 1900
- Vol. 27, Issue 1, 7 (2000)
Diode Pumped High Repetition Rate Q-switched Nd:YVO41342 nm Laser
[in Chinese], [in Chinese], [in Chinese], [in Chinese], and [in Chinese]
An acousto-optically Q-switched diode-pumped Nd:YVO41342 nm laser emits short pulses at kilohertz repetition rates. The laser generates a maximum average power of 1.14 W, peak power of 1.27 kW and pulse width of 56 ns (FWHM) at a pulse repetition rate of 15 kHz. With a LBO crystal as the frequency doubler outside the cAn acousto-optically Q-switched diode-pumped Nd:YVO41342 nm laser emits short pulses at kilohertz repetition rates. The laser generates a maximum average power of 1.14 W, peak power of 1.27 kW and pulse width of 56 ns (FWHM) at a pulse repetition rate of 15 kHz. With a LBO crystal as the frequency doubler outside the cavity, about 30 mW of 671 nm laser output is obtained..
Chinese Journal of Lasers
- Publication Date: Jan. 01, 1900
- Vol. 27, Issue 1, 11 (2000)
Comparison of Characteristics of X-Ray Emission And Its Spatial Distributions in an Alumium Plasma Using fs and ns Laser Pulses
[in Chinese], [in Chinese], [in Chinese], and [in Chinese]
The characteristics of X-ray emission in aluminum plasmas using 45 fs and 6 ns pulsed lasers respectively are reported. It shows that under the fs laser, the X-ray emission is dominantly from the K shell, the aluminum plasma′s temperature is 500 eV and the electron density is 3×1021/cm3, while under the ns laser, The characteristics of X-ray emission in aluminum plasmas using 45 fs and 6 ns pulsed lasers respectively are reported. It shows that under the fs laser, the X-ray emission is dominantly from the K shell, the aluminum plasma′s temperature is 500 eV and the electron density is 3×1021/cm3, while under the ns laser, the L shell, 100eV and 2×1020/cm3 are obtained correspondingly. The spatial distributions are also compared simply..
Chinese Journal of Lasers
- Publication Date: Jan. 01, 1900
- Vol. 27, Issue 1, 42 (2000)
A General Theory of the Threshold Condition of Double Resonance Parametric Oscillation
[in Chinese], [in Chinese], and [in Chinese]
This paper deals with the threshold condition of double resonance parametric oscillation when the absorption coefficient of the signal light is different from that of the idling light. A general expression of threshold condition was obtained and discussed. The result becomes that of the widely-accepted theory when the This paper deals with the threshold condition of double resonance parametric oscillation when the absorption coefficient of the signal light is different from that of the idling light. A general expression of threshold condition was obtained and discussed. The result becomes that of the widely-accepted theory when the absorption coefficient of the signal light is the same with that of the idling light, therefore the threshold condition in this paper is universal..
Chinese Journal of Lasers
- Publication Date: Jan. 01, 1900
- Vol. 27, Issue 1, 47 (2000)
Study of SBS Pulse Waveform in a One-cell System
[in Chinese], [in Chinese], [in Chinese], [in Chinese], and [in Chinese]
The influence of configuration parameters in a one-cell system on the pulse waveform of stimulated Brillouin scattering was investigated experimentally. The Stokes pulsewidth was easily changed from 1.5 to 8 ns by varying the lens focus and the distance between the lens and the SBS cell. The SBS pulse waveform was numeThe influence of configuration parameters in a one-cell system on the pulse waveform of stimulated Brillouin scattering was investigated experimentally. The Stokes pulsewidth was easily changed from 1.5 to 8 ns by varying the lens focus and the distance between the lens and the SBS cell. The SBS pulse waveform was numerically simulated by the theory model of stimulated Brillouin scattering initiated by thermally excited acoustic waves. The theoretical calculation was coincident with experiment results well..
Chinese Journal of Lasers
- Publication Date: Jan. 01, 1900
- Vol. 27, Issue 1, 53 (2000)
Observation of Spectra on an Atomic Beam in a Slow-microwave Field Using the Optical Pumping
[in Chinese], [in Chinese], and [in Chinese]
This paper reports the observation of a spectrum on an atomic beam in slow-microwave fields using the optical pumping. The spectrum is given in standing microwave fields when the slow-wave factors of helix structures are 5.20 and 10.67 respectively. Doppler shift varying with the slow-wave factor is observed experimentThis paper reports the observation of a spectrum on an atomic beam in slow-microwave fields using the optical pumping. The spectrum is given in standing microwave fields when the slow-wave factors of helix structures are 5.20 and 10.67 respectively. Doppler shift varying with the slow-wave factor is observed experimentally, and the influece of the field polarization on the spectrum is discussed. The boardening of the spectral line in the spectrum when the helix stucture is perpendicular to the atomic beam is also observed and discussed..
Chinese Journal of Lasers
- Publication Date: Jan. 01, 1900
- Vol. 27, Issue 1, 59 (2000)
Superbroadband Raman Compression in Hydrogen
[in Chinese], [in Chinese], [in Chinese], [in Chinese], and [in Chinese]
Experiments of superbroadband Raman compression in hydrogen gases were conducted. The Raman seeds of 6 ns pulse duration were obtained from a near-threshold oscillator pumped by an excimer laser pulse of 23 ns. Then the seeds were amplified 3 times in a backward Raman amplifier. The effects of pressure and mixture of RExperiments of superbroadband Raman compression in hydrogen gases were conducted. The Raman seeds of 6 ns pulse duration were obtained from a near-threshold oscillator pumped by an excimer laser pulse of 23 ns. Then the seeds were amplified 3 times in a backward Raman amplifier. The effects of pressure and mixture of Raman gases were discussed..
Chinese Journal of Lasers
- Publication Date: Jan. 01, 1900
- Vol. 27, Issue 1, 64 (2000)
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