Chinese Journal of Lasers
Co-Editors-in-Chief
Ruxin Li
[in Chinese], [in Chinese], and [in Chinese]

A multi arm Michelson interferometric system for the shaping of the nanosecond laser pulse is designed. Process of the pulse shaping by an all optical method is analyzed theoretically. According to a specially designed pulse shape for the purpose of ICF targeting usage, parameters of the system are calculated. In conclusion, when the width of the shaped laser pulse is in the range from 2 times to 4 times the width of the primary input pulse, the pulse shaping system works well.

Jan. 01, 1900
  • Vol. 25 Issue 6 490 (1998)
  • [in Chinese], [in Chinese], [in Chinese], [in Chinese], and [in Chinese]

    The principle to measure S-parameters of microwave devices with ultrashort optical pulses has been described. The measuring system with a maximum frequency up to 100 GHz has been developed. We have measured the devices with a frequency of 36 GHz. The results agree well with those measured by using a network analyzer.

    Jan. 01, 1900
  • Vol. 25 Issue 6 495 (1998)
  • [in Chinese], and [in Chinese]

    The light gathering power for an ultrasound receiver with a confocal Fabry Perot interferometer is analyzed in detail. The light gathering power of the interferometer, the etendue in the object space and the conditions of matching one to the another are given. Parts of experimental results obtained in the matching conditions are presented.

    Jan. 01, 1900
  • Vol. 25 Issue 6 500 (1998)
  • [in Chinese], and [in Chinese]

    A proposal of accelarating electrons in vacuum by using an ultrashort laser pulse is given in this paper, and its feasibility is discussed in detail. It is shown that the numerical results are in good agreement with the theoretical analysis. This scheme is simple and feasible for practical applications.

    Jan. 01, 1900
  • Vol. 25 Issue 6 505 (1998)
  • [in Chinese]

    A polarized scanning camera used for dynamic measurement of thermal deformation fields is proposed. The whole dynamic thermal deformation information of an object can be recorded simultaneously on a specklegram in one step, and reappeared continuously during whole field filtering.

    Jan. 01, 1900
  • Vol. 25 Issue 6 509 (1998)
  • [in Chinese], [in Chinese], and [in Chinese]

    In this paper, a simple and excellent etched fiberoptic sensor network which is embedded in the laminated composite materials structure of the vertical tail wing of a training 11 plane is used to measure the structural states, such as strain, stress and damage induced by an external impact. Experimental results have shown the feasibility of this measuring method.

    Jan. 01, 1900
  • Vol. 25 Issue 6 513 (1998)
  • [in Chinese], [in Chinese], and [in Chinese]

    In this paper, the electro optical properties of a KNbO3 single crystal was studied. A KNbO3 deflector with four cylindrical electrodes, which utilizes the coefficient γ33 of the EO tensor, was made. Results of the experiment indicated that the fundamental figure of merit of the KNbO3 deflector was about twice that of the LiNbO3 crystal with equal structural parameters, aperture and length.

    Jan. 01, 1900
  • Vol. 25 Issue 6 519 (1998)
  • [in Chinese], [in Chinese], [in Chinese], and [in Chinese]

    Based on an 8f single passage filtering system, using a switch circuit to control the pervirs limits of two twisted nematic mode field effected matrix addressing liquid crystal boxes and using them as a band pass filter, the wide bandwidth, real time, steady and flexible optical wavelet transform is implemented.

    Jan. 01, 1900
  • Vol. 25 Issue 6 523 (1998)
  • [in Chinese], and [in Chinese]

    A new method of recording the transmission marking 2D/3D rainbow hologram was put forward. It uses directly a scattered slit beam to illuminate the 2D transmission marking. The transmitted light was recorded on the master hologram. The latter can be recorded according to the colour separation and layer separation like the general two step rainbow hologram. But it broke through the limit of the length and area of the general hologram on the brightness and the viewing angle of the reconstructed image, thus the large viewing angle and high brightness were achieved. The feasibility and parameters of the optical set-up were discussed in detail and the satisfactory experimental results were obtained.

    Jan. 01, 1900
  • Vol. 25 Issue 6 546 (1998)
  • [in Chinese], [in Chinese], [in Chinese], and [in Chinese]

    In the WDM optical network, a tunable F-P cavity is often used as a demultiplexer. But the traditional structure has the shortcoming that the reflective light is too strong and this will bring trouble to the transmmiter and EDFA in the network system. To solve this problem, isolators are often used. But this will cause an extra loss. Besides, it will costs too much. A new type of tunable F P cavity is designed in this paper. Its insert loss is low and there is almost no reflective light from the F-P cavity. Finally, it can be tuned electronically.

    Jan. 01, 1900
  • Vol. 25 Issue 6 551 (1998)
  • [in Chinese], [in Chinese], [in Chinese], [in Chinese], [in Chinese], [in Chinese], and [in Chinese]

    An experimental method, result and practical meaning for the observation of micro leakage magnetic fields are presented by means of electron holography in this paper.

    Jan. 01, 1900
  • Vol. 25 Issue 6 557 (1998)
  • [in Chinese], [in Chinese], [in Chinese], [in Chinese], and [in Chinese]

    The spectra of the optical and acoustic signals emitted by a plasma during laser welding were studied through fast Fourier transformation. It was found that when the laser welding process was stable there existed obviouse line spectra in both optical and acoustic signals at 300 Hz. When poor penetration appeared, the spectra of them were dominantly continuous. These results provided a new way to increase the defect monitoring accuracy.

    Jan. 01, 1900
  • Vol. 25 Issue 6 570 (1998)
  • [in Chinese], [in Chinese], [in Chinese], [in Chinese], and [in Chinese]

    An analyzing instrument of the Ronchi ruling type for measuring TEM00 made Gaussian beam parameters of lasers in quality control in industry is described. The instrument can be used to measure cross field distrbution of a Gaussian beam and used in the measurements of the 1/e2 beam diameter and the far field beam divergence in the near field. The basic principle of the measurement and the experimental results are reported.

    Jan. 01, 1900
  • Vol. 25 Issue 6 573 (1998)
  • [in Chinese], [in Chinese], [in Chinese], [in Chinese], [in Chinese], and [in Chinese]

    The wavelength tunable range was widened in a three electric section strained multi quantum well distributed feedback laser by using the gain lever effect. When the fixed bias currents are injected into the two sections, another section is the control section (its length is 0.33 of the all cavity length). The lasing wavelength becomes longer when the current of the control section is increased. The maximum continuous tuning range (without mode hopping) is 0.82 nm at 1.538 μm. It still can be continuously tuned after mode hopping.

    Jan. 01, 1900
  • Vol. 25 Issue 6 481 (1998)
  • [in Chinese], [in Chinese], [in Chinese], [in Chinese], [in Chinese], and [in Chinese]

    In this paper, a new electrical tuning method for an external cavity semiconductor laser is presented. The continuous tuning condition is theoretically and experimentally analyzed. A single PZT (Bimorph) is used to change both the cavity length and the grating angle. The cavity structure is so designed that the continuous tuning condition can be satisfied. The scanning angle of the bimorph is about 1°. As wide as 15 nm a tuning range and a 50GHz continuous range (without mode hopping) are obtained.

    Jan. 01, 1900
  • Vol. 25 Issue 6 485 (1998)
  • [in Chinese], [in Chinese], and [in Chinese]

    A pulsed laser was used to irradiate the surface of a HgCdTe target, and a time and space resolved diagnostic technique was used to detect the emission spectrum from the plasma. The ejected velocity of the plasma was measured by using obtained time of flight curves. According to the shape of the continuum, the plasma temperature was calculated using the Plank′s formula. On the basis of the experimental results, the properties of the HgCdTe plasma were discussed.

    Jan. 01, 1900
  • Vol. 25 Issue 6 528 (1998)
  • [in Chinese], and [in Chinese]

    The dynamic equations for the new model of laser based on the photon boson elementary excitation coupling is simplified and solved numerically. A lot of interesting and potentially useful results, such as square quasi periodic self pulses and periodic chaotic motions, are found and discussed.

    Jan. 01, 1900
  • Vol. 25 Issue 6 533 (1998)
  • [in Chinese], [in Chinese], and [in Chinese]

    This paper presents a method of intensity thresholding for the laser speckle patterns of multi gray levels (for example 256 levels). After this thresholding operation, the main features of the spacial frequency power spectral density of laser speckle intensity are maintained and the amount of computer digital storage space can be reduced greatly. An optimum threshold level is found that minimizes distortion of the power spectrum for speckle data of the circular and ring apertures.

    Jan. 01, 1900
  • Vol. 25 Issue 6 539 (1998)
  • [in Chinese], [in Chinese], and [in Chinese]

    The experimental results of the far field beam spread angle of the first Stokes output of a KrF/H2 Stimulated Raman Scattering system are presented. The effects of focus parameters on the beam spread angle of the first Stokes output are discussed.

    Jan. 01, 1900
  • Vol. 25 Issue 6 543 (1998)
  • [in Chinese], [in Chinese], [in Chinese], and [in Chinese]

    The visible upconversion luminescence spectra of Ho3+ sensitized by Yb3+ were measured in different double doped (Yb3+-Ho3+) glasses under LD (0.97 μm) excitation at A.T. The fluorescence lifetimes of Yb3+ ions in single or double doped glasses were presented, and lifetimes of Yb3+ in (Yb3++Ho3+) doped glasses were smaller than those of Yb3+ doped glasses only. The upconversion luminescence of Ho3+ sensitized by Yb3+ is the most efficient, and the mechanism of the sensitization luminescence was discussed.

    Jan. 01, 1900
  • Vol. 25 Issue 6 561 (1998)
  • [in Chinese], [in Chinese], [in Chinese], [in Chinese], and [in Chinese]

    Reported here is a result of absolute reflectivity measurement carried out in a soft X-ray laser plasma experiment. A 26.2% reflectivity Mo/Si multilayer for 13.1 nm soft X-ray at the 45° incidence angle is obtained.

    Jan. 01, 1900
  • Vol. 25 Issue 6 565 (1998)
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