Acta Optica Sinica
Co-Editors-in-Chief
Qihuang Gong
[in Chinese], [in Chinese], and [in Chinese]

The grating imaging system which could be used in X ray spectrum characterization is studied. By using the theory of partial coherence, the imaging quality and the system transfer function are analysed. A new method for solving the spectrum is proposed.

Jan. 01, 1900
  • Vol. 17 Issue 4 465 (1997)
  • [in Chinese], [in Chinese], [in Chinese], [in Chinese], and [in Chinese]

    Based on two stage erbium fiber and optical loop couping configuration, 980 nm and 1480 nm LD pumped erbium doped fiber amplifier (EDFA) has been developed. The characteristics of EDFA have investigated experimentally at wavelength of 1553 nm. Results show that the small signal gain, noise figure and maximum output power are of 42.8 dB, 4.4 dB and 15.2 dBm, respectively.

    Jan. 01, 1900
  • Vol. 17 Issue 4 472 (1997)
  • [in Chinese]

    Analytical solutions of electromagnetic fields in the step index chiral fiber which both the core and the cladding are chiral media have been presented. The modal characteristic equation is derived. The expressions of electromagnetic field components, intensities and powers of guided modes in the chiral fiber are given. Effects of chirality on guided modes in the chiral fiber are investigated.

    Jan. 01, 1900
  • Vol. 17 Issue 4 476 (1997)
  • [in Chinese], [in Chinese], [in Chinese], and [in Chinese]

    A full-wave numerical approach, based on the two-dimensional finite difference time domain (FDTD) method, is developed for the accurate analysis of channel multilayer and multiple quantum well (MQW) waveguides. Numerical results in terms of field distributions and dispersion characteristics are given and compared with available results obtained with vector finite element method. The scalar approximation technique, based on the 2-D FDTD method, is also investigated and it's limitations of the validity and accuracy are pointed out.

    Jan. 01, 1900
  • Vol. 17 Issue 4 482 (1997)
  • [in Chinese], [in Chinese], [in Chinese], [in Chinese], [in Chinese], and [in Chinese]

    The optical properties of SiN x films prepared by microwave ECR CVD have been investigated.The wide transmission spectrum and high transmissivity of SiN x films are obtained. The effects of microwave power and substrate temperature on transmission spectra, refractive index, optical band gap are analysed.

    Jan. 01, 1900
  • Vol. 17 Issue 4 489 (1997)
  • [in Chinese], [in Chinese], and [in Chinese]

    A new method of speckle metrology techniques called optical flow analysis is proposed based on dynamic scene analysis. From a new point of view, the probability of using the concept of image sequence processing to analyse speckle patterns is discussed in detail. It is proved that if speckle patterns do not meet the constrained conditions for optical flow analyses, a multichannel image processing method can be used to change the continued distribution of images to expand the measurement range. With classical metrology techniques, speckle patterns must be processed in spatial frequency domains. But by using optical flow analyses, speckle patterns can be directly processed in spatial domains. It provides a new way to reach the real-time measurement of speckle patterns.

    Jan. 01, 1900
  • Vol. 17 Issue 4 434 (1997)
  • [in Chinese], [in Chinese], and [in Chinese]

    A new simple approach to get high quality edge lit hologram is presented. This kind of hologram can be displayed even in strong environment lights and can be integrated with light bulbs into planar compact samples. This new technology is expected to have a wide applications in industry and entertainment.

    Jan. 01, 1900
  • Vol. 17 Issue 4 442 (1997)
  • [in Chinese], and [in Chinese]

    A new mapping algorithm between real world coordinate and CCD coordinate for 3 D sensing with laser sheet triangulation is presented and verified by experiment. Two mapping curved planes are generated with the characteristic of moire patters that is formed by laser sheet. We can get the real world coordinate z and y of every point in the surface of CCD camera simultaneously through these two mapping curve plane.

    Jan. 01, 1900
  • Vol. 17 Issue 4 447 (1997)
  • [in Chinese], and [in Chinese]

    A new method of phase measuring profilometry, which uses only two samples of the coded intensity, is presented. By using polarization property, a two channel measuring system is designed, by which the two samples can be recorded simultaneously. Based on this system, the phase measuring profilometry can be used in the measurement of dynamic profile. This method broadens the application range of the measuring profilometry. The experimental results verify the reliability of the proposed methods.

    Jan. 01, 1900
  • Vol. 17 Issue 4 452 (1997)
  • [in Chinese], and [in Chinese]

    A phase modulated real time joint transform correlator is proposed, in which a liquid crystal display screen is adopted as an input device and the joint power spectrum is recorded and displayed by a liquid crystal light valve. The diffraction orders of the grating type structure on the liquid crystal display screen are utilized in this system. As a result, it can use the light energy as well as the physical area of the liquid crystal light valve more efficiently. In order to suit low-resolution of the liquid crystal light valve, and imaging lens is applied to amplifying joint frequency spectrum of the diffraction orders. The two oblique parallel plane glass plates are inserted in the correlator to manipulate the phase differences between the reference image and the target image of the diffraction orders. This technique yields better output correlation performences than the classical real-time joint transform correlator. The experimental results verified the correctness of the system design and performance analysis.

    Jan. 01, 1900
  • Vol. 17 Issue 4 456 (1997)
  • [in Chinese], [in Chinese], [in Chinese], [in Chinese], and [in Chinese]

    Wavelet transforms are very effective for analyzing the information content of signal. In this paper, we propose a novel digital matrix vector multiplication and the incoherent optical correlator to compute discrete wavelet transforms. The application of this representation to signal processing is discussed.

    Jan. 01, 1900
  • Vol. 17 Issue 4 461 (1997)
  • [in Chinese], [in Chinese], [in Chinese], and [in Chinese]

    The differences between autocorrelation and triple correlation are studied in contrast ratio measurement of amplified laser pulses. Theoretical analysis shows that triple correlation can not only locate the right position of the noise pulse, but also has higher accuracy than autocorrelation. These results are verified by numerical calculation.

    Jan. 01, 1900
  • Vol. 17 Issue 4 493 (1997)
  • [in Chinese], and [in Chinese]

    We presents a theoretical analysis on a self injected excimer laser (SIEL) with 1~10 ns continuous width tunable pulses output from a typical commercial excimer laser. The operational characteristics and the basic requirements were given. The results agree with the recent published experimental results of SIEL.

    Jan. 01, 1900
  • Vol. 17 Issue 4 385 (1997)
  • [in Chinese], [in Chinese], [in Chinese], [in Chinese], [in Chinese], and [in Chinese]

    Up to now, the development of the first stage of ICF solid state laser driver is to replace the pumping flash lamp by the laser diode which has much better stability and to replace the buik optic modulator by integrated optics and fiber techology for laser pulse forming. We study experimentally the laser pulse forming techology using a laser diode pumped solid state laser and a integrated waveguide modulator. The foundmental results are obtained which will be of great importance to the laser pulse formation of the new ICF laser drive system.

    Jan. 01, 1900
  • Vol. 17 Issue 4 393 (1997)
  • [in Chinese], [in Chinese], and [in Chinese]

    The laser produced plasma channel may be a promising means to produce an efficient compact soft X ray laser. The plasma parameters in such a plasma waveguide are calculated with a self similar model. It is shown that nonequilibrium underdense plasmas and candidate ions for recombination laser schemes can be obtained. As an example, the laser gains of the transition 1s3d-1s2p of He like nitrogen ions are calculated for given pumping energies and different initial gas densities.

    Jan. 01, 1900
  • Vol. 17 Issue 4 399 (1997)
  • [in Chinese], [in Chinese], [in Chinese], [in Chinese], and [in Chinese]

    The third order optical nonlinearities of SnO2 nanoparticles were studied in a nonresonant region by Z-scan technique with 18 ns, 0.53 μm pulses from a Q-switched Nd:YAG laser. The sign and magnitude of the third order nonlinear susceptibility χ(3) and two photon absorption coefficient β, et al., of SnO2 nanoparticles with different size were obtained. The experimental results were discussed in terms of the quantum confined effect.

    Jan. 01, 1900
  • Vol. 17 Issue 4 423 (1997)
  • [in Chinese], [in Chinese], [in Chinese], and [in Chinese]

    Doping ZnO into LiNbO3, Zn:LiNbO3 crystal have been grown. The photo damage resistance increases of two magnituder when the ZnO doping concentrations were higher than 6 mol%. This value is similar to that of MgO(>4.6 mol%):LiNbO 3. The frequency doubling conversion efficiency of Zn (6 mol%):LiNbO3 was measured to be about 5%, ligher than that of Mg (6 mol%):LiNbO3. The location of Zn2+ ions and the enhancement machenism of photo damage resistance of Zn:LiNbO3 are discussed in this paper.

    Jan. 01, 1900
  • Vol. 17 Issue 4 430 (1997)
  • [in Chinese], [in Chinese], [in Chinese], [in Chinese], [in Chinese], [in Chinese], and [in Chinese]

    In this paper, the energy transfer processes between Pr 3+ ions and Yb 3+ ions were studied in upconversion luminescence of Pr, Yb:ZBLAN. There are three ways for the energy transfer from Yb 3+ to Pr 3+ . Yb 3+ ions act as sensitisers in the upconversion luminescence of Pr 3+ ions. There are also three energy transfer paths from Pr 3+ ions to Yb 3+ ions, which quenches the luminescence of Pr 3+ ions and results in saturation of luminescence of Pr 3+ ions with the increasing concentration of Yb3+ ions.

    Jan. 01, 1900
  • Vol. 17 Issue 4 403 (1997)
  • [in Chinese], [in Chinese], [in Chinese], and [in Chinese]

    A triangular non Bravais lattice was designed in this paper, the crystal constructed form dielectric rods in air background can generate a common band gap for both orthogonal polarizations E and H that is called absolute photonic band gap, but the crystal constructed from air circular holes in dielectric matrix can not generate an absolute photonic band gap. The effective long wavelength dielectric constant of this crystal has been calculated using photonic band structure, simultaneously, the results agree with electrostatic theory well.

    Jan. 01, 1900
  • Vol. 17 Issue 4 409 (1997)
  • [in Chinese], [in Chinese], [in Chinese], [in Chinese], [in Chinese], [in Chinese], and [in Chinese]

    This paper reports the angular distribution of scattered lights from interaction of 0.53 μm laser light with Au disks. The experimental results of the angular distribution is different with what SBS theory predicts. These experiments show that SRS energy is much lower than that of scattered lights. So SRS can not be the mechanism of producing these scattered lights, which could come from specular reflection.

    Jan. 01, 1900
  • Vol. 17 Issue 4 414 (1997)
  • [in Chinese], [in Chinese], [in Chinese], [in Chinese], and [in Chinese]

    The P N junctions were produced by pulsed 1.06 μm Nd:YAG laser induced diffusion of Zn into substrate GaAs with solid state diffusion source. The performance parameters of the P N junctions such as X j and C(x,t,T) are presented as the functions of the laser pulse number N and the power density of the exposed region. The experimental results show that junction depth X j reaches submicrometer and the dopant concentration is of the order of 10 20 cm -3.

    Jan. 01, 1900
  • Vol. 17 Issue 4 419 (1997)
  • [in Chinese], [in Chinese], and [in Chinese]

    All fiber reflectors using two stage directional couplers are proposed. The reflectivity and transmissivity of both optical field and intensity are derived. And the characteristics of such reflectors are analyzed and compared for each basic reflector configuration.

    Jan. 01, 1900
  • Vol. 17 Issue 4 497 (1997)
  • [in Chinese], [in Chinese], [in Chinese], [in Chinese], and [in Chinese]

    The characteristics of optical fiber Bragg reflective filter (FBR) are analyzed on the basis of asymmetric six layer optical waveguide model using an improved perturbation procedure for investigating dielectric gratings. The influences of waveguide structural parameters, mainly the thickness of the high index layer, on the characteristics of FBR are discussed. The experimental method of controlling FBR reflectivity during the fabrication process is given . At 1.55 μm region, FBR devices with reflectivity up to 96% and reflection bandwidth (FWHM) about 1.5 nm are fabricated.

    Jan. 01, 1900
  • Vol. 17 Issue 4 503 (1997)
  • [in Chinese], [in Chinese], [in Chinese], and [in Chinese]

    By using oblique avaporation of SiO, uniform alignment of ferroeletric liquid crystal (FLC) is realized. For a FLC monodomain aligned by this method, the contrast is 150:1, the response time is 60 μs and the bistability is excellent. A 64×64 electric addressed FLCSLM is also obtained by the same method, its contrast is higher than 80:1 and frame rate is higher than 39 /s.

    Jan. 01, 1900
  • Vol. 17 Issue 4 508 (1997)
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