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

This paper introduced a new method to recover the original wave-front in lateralshearing interferogram. By using Fourier transformation, the original wave-front can be recovered with higher precision and in more details. The only limit to it is the errors of relative experiment and data sampling.

Jan. 01, 1900
  • Vol. 26 Issue 11 982 (1999)
  • [in Chinese], [in Chinese], [in Chinese], [in Chinese], and [in Chinese]

    Two methods for determining the residual nonlinear error of a dual-frequency interferometer are proposed. The first is an estimation method, which can get the nonlinearity error based on the amplitude modulation of the measuring signal when moving the reference mirror of the interferometer continuously. This method has the advantages of easy operating and high resistance to the environment influence. The second is nanometer calibration, which can trace the measurement result to meter definition. In this paper, a dual-frequency interferometer named SJD5 with nanometric capability is introduced.Nanometer calibration between SJD5 and a F-P interferometer of the National Institute of Metrology (NIM ) is also described in detail. The residual nonlinearity of SJD5 is determined as 1. 4 nm by the estimated method and less than 2. 5 nm by nanometer calibration. These two results fit well with each other under consideration of environment influence.

    Jan. 01, 1900
  • Vol. 26 Issue 11 987 (1999)
  • [in Chinese], [in Chinese], [in Chinese], and [in Chinese]

    Two kinds of binary optical elements used in the multichannel frequency spectrum analysis are introduced. One is prepared by overlapping two line-type zone plates. It acts as a two-cylindrical lens system. The other is prepared by overlapping a line-type zone plate and a circular zone plate. It has the effect of a system that consists of a cylindrical lens and a spherical lens. The focal length in x direction of these elements is two times that in y direction, so that if put an object in the focal distance (fx), its Fourier frequency spectrum in x direction and its image in y direction on the focal plane in the distance fx can be got. In this paper, the principle, the technique, the data and the result of these elements are also given.

    Jan. 01, 1900
  • Vol. 26 Issue 11 993 (1999)
  • [in Chinese], [in Chinese], [in Chinese], and [in Chinese]

    A Quadrilayer with PtCo alloy as a MO layer was suecessfully prepared. Based on the quadrilayer,the effect of the thickness of each layer upon Keer rotation, reflectivity and figure of merit was studied and an optimum optical structure was shown. For the thermal design, an optimum structure suitable for thermo-magnetic recording was obtained.When considering the effect of the reflectivity, the Keer rotation can be enhenced by decreasing the reflectivity. Therefore, the structure design shoud be carried out by considering reflectivity, Keer rotation and temperature of the MO layer at the same time.An optimum thermal and optical structure was given.

    Jan. 01, 1900
  • Vol. 26 Issue 11 997 (1999)
  • [in Chinese], [in Chinese], [in Chinese], [in Chinese], and [in Chinese]

    The wavelength conversion of 1 GHz, 11 ps ultrashort optical pulses based on cross-gain modulation of a semiconductor optical amplifier is reported. The phenomena of the experiment are analyzed. The following experimental results are obtained: (1 ) The converted signal is obviously broadened, the full width at half-maximum (FWHM) of the converted signal is 20 times that of the initial signal laser; (2) The spectrum of the converted signal is compressedj (3) The central wavelength of the converted signal is redshifted ; (4) The extinction ratio of the converted signal is decreased.

    Jan. 01, 1900
  • Vol. 26 Issue 11 1003 (1999)
  • [in Chinese], [in Chinese], [in Chinese], [in Chinese], and [in Chinese]

    An erbium-doped fiber amplifier (EDFA) gain-clamped to a flat gain spectral region was designed and built up. The dynamic gain equalized transmission over an 8 × 2.5Gb/s ×450 km WDM system with a G.652 fiber was demonstrated by using cascaded gainclamped EDFAs. When the channel number changed, the sensibility of the receiver varied only 0.5 dB at BER of 10-12.

    Jan. 01, 1900
  • Vol. 26 Issue 11 1021 (1999)
  • [in Chinese], and [in Chinese]

    This paper discusses the reflectance measurement of the magneto-optical disk using a comparison method, and describes the effects of the optical system's nonideal condition. A test system has been designed to quickly and accurately measure the reflectance of the magneto-optical disk.

    Jan. 01, 1900
  • Vol. 26 Issue 11 1027 (1999)
  • [in Chinese], [in Chinese], [in Chinese], [in Chinese], and [in Chinese]

    An optoelectronic automatic real-time human face recognition system, which includes a feature point extractor, a normalization algorithm, an encoding module, an optical recognizer based on hit/ miss transform and an incoherent correlator, and a postprocessing module is presented in this paper. When a real-time face image is captured, three reference points including two internal corners of both eyes and the mouth center, are extracted automatically for normalizing use. Then the face image is normalized to a fixed scale and posture by using the affine transform. The normalized image will then be encoded to an extensive complementary encoding image and be sent to an incoherent correlator based optical processor to be recognized. Experimental results are given.

    Jan. 01, 1900
  • Vol. 26 Issue 11 1031 (1999)
  • [in Chinese], [in Chinese], [in Chinese], [in Chinese], and [in Chinese]

    The X-ray diffraction and laser Raman techniques have been employed to analyse the situation of the tungsten impurity in α-Al2O3 grains in the samples of the Al2O3WO3system synthesized by a high power CO2 laser. The expermental results reveal that tungsten ions exist in the α -Al2O3lattice through replacing Al+3.

    Jan. 01, 1900
  • Vol. 26 Issue 11 1041 (1999)
  • [in Chinese], and [in Chinese]

    Single pass powder-feeding laser cladding was carried out with different scanning speeds, powder feeding rates and powder sizes. The influence of the processing parameters on the morphology and structure at and adjacent to the interface formed between the coating and the substrate was studied by means of optical and electron microscopy.

    Jan. 01, 1900
  • Vol. 26 Issue 11 1047 (1999)
  • [in Chinese], [in Chinese], [in Chinese], [in Chinese], [in Chinese], [in Chinese], and [in Chinese]

    The PAP cDNA controlled by a wound-inducible promoter was introduced into Brassica napus via laser microbeam puncture, and plantlets resistant to Gentamycin were obtained. The transgenicity of these plantlets was verified by PCR amplification and the Southern blotting analysis, which showed that PAP cDNA together with the woundinducible promoter and a terminator have been integrated into the rape genome, with the transformation frequency being 1. 7%. The test of virus challenge showed that all these transgenic rape plants were resistant to virus TuMV mechanically inoculated in higher degree.

    Jan. 01, 1900
  • Vol. 26 Issue 11 1053 (1999)
  • [in Chinese], [in Chinese], [in Chinese], and [in Chinese]

    A high repetition rate diode pumped Nd:YAG laser, passively Q -switched with a Cr4+: YAG plate, has been analysed. lt shows that the output energy and the pulse width depend on the pump energy, the initial transmitance of the Cr4+: YAG and the reflectivity of the output mirror. Based on the results of the calculation, an experiment has been performed and a 12 ns Q -switched laser pulse output of 13 mJ under pulse repetition rate of 100 Hz is obtained.

    Jan. 01, 1900
  • Vol. 26 Issue 11 961 (1999)
  • [in Chinese], [in Chinese], [in Chinese], [in Chinese], [in Chinese], [in Chinese], [in Chinese], [in Chinese], and [in Chinese]

    A Yb3+-doped ring silica fiber laser is reported. The single spatial mode laser operates at 1041 nm with a linewidth being 3. 16 nm when pumped by a 981. 5 nm laser diode. The pumping threshold is 1. 4 mW, and the slope efficiency is 8%.

    Jan. 01, 1900
  • Vol. 26 Issue 11 965 (1999)
  • [in Chinese], [in Chinese], [in Chinese], [in Chinese], and [in Chinese]

    An eye-safe laser source at 1. 57 μm with a maximum 64% energy conversion efficiency is demonstrated by use of a noncritically phase-matched (θ = 90℃, = 0°) KTP optical parametric oscillator pumped by a 1. 064 μm Nd: YAG laser. The effects of the noncritical phase-matching method on the walkoff angle and the acceptance angle of KTP crystal are analyzed and the operation properties such as threshold, efficiency and output beam quality of the OPO are discussed.

    Jan. 01, 1900
  • Vol. 26 Issue 11 969 (1999)
  • [in Chinese], [in Chinese], [in Chinese], [in Chinese], [in Chinese], and [in Chinese]

    This paper introduces a fundamental description and experimenal results of a copper vaper laser (CVL) using two thyratrons as the prime switch of an electric power supply. The input electrical power is 10 kW, and the maximum laser output power is 100 W. The domestic thyratron works efficiently and normally.

    Jan. 01, 1900
  • Vol. 26 Issue 11 973 (1999)
  • [in Chinese], [in Chinese], and [in Chinese]

    A gas mixture of xenon or krypton with a hot vapor of rubidium was excited to obtain a diffuse emission band centered at 159 nm from (XeCs)+ and at 131 nm from (KrCs)+ molecular ions. The observed emission bands are assigned to be the 21Σ +-11Σ +transition of (XeCs) + and (KrCs) +, respectively.

    Jan. 01, 1900
  • Vol. 26 Issue 11 977 (1999)
  • [in Chinese], [in Chinese], and [in Chinese]

    The effect of phenolic resin on laser ignition of B/KNO3 was studied by detecting the delay time of ignition of a composite, and by means of EMS and DSC as wel1. It was shown that the igniting delay time and the strength of the photoacoustic signal of B/KNO_3 with phenolic resin are smaller than those without phenolic resin at certain laser energy. Phenolic resin prevents the energy and the mass transfering to environment.According to the analysis of the ablated spots by EMS, the difference between B/KNO3 and B/KNO3/phenolic resin is small. A lot of ignition centers are formed at the surface of the composite by the incident laser.

    Jan. 01, 1900
  • Vol. 26 Issue 11 1007 (1999)
  • [in Chinese], [in Chinese], and [in Chinese]

    In this paper, from the structural feature of the Fibonacci super-lattice, and based on the principles of group velocity dispersion and propagating characteristics of the ultra-short pulse, the pulse shape de formation by group velocity dispersion is studied.

    Jan. 01, 1900
  • Vol. 26 Issue 11 1011 (1999)
  • [in Chinese], [in Chinese], [in Chinese], [in Chinese], and [in Chinese]

    An invertigation of mechanisms of self-pumped phase conjugation (SPPC) in BaTio3: Ce crystal in the green, λ = 514. 5 nm on pump beam parameters, such as the beam diameter, the incidence angle and the position was reported. It was found that the SPPC mechanism changed from a "cat" (FWM-TIM) mechanism to a stimulated photorefractive backscattering and four- wave-mixing (FWM- SPB) when the pump beam diameter, the incidence angle and position were varied, with a transition of FWM-TIR + FWM-SPB mechanism coexisted.

    Jan. 01, 1900
  • Vol. 26 Issue 11 1016 (1999)
  • [in Chinese], [in Chinese], [in Chinese], [in Chinese], [in Chinese], [in Chinese], and [in Chinese]

    In the light of annealing data about Cr,Ca:Y3Al5O12 crystals with various Ca/Cr content ratios, we established a set of solid-state defect reaction formulas describing the formation of the four-coordinated quadra-valence Cr4+ laser center in the crystal. The valence state of the Cr4+ laser center depends mainly on the divalent Ca2+ compensation ion in the crystal, which can introduce an oxygen vacancy into the crystal. The concentration of the Cr4+ laser center has also been estimated and indicated that its absorption cross-section at 1064 nm wavelength is most probably 5.7 ×10-18 cm2.

    Jan. 01, 1900
  • Vol. 26 Issue 11 1036 (1999)
  • Please enter the answer below before you can view the full text.
    Submit