Acta Optica Sinica
Co-Editors-in-Chief
Qihuang Gong
Sun Zheng, Ning Hui, Xie Yongjie, and Wu Longlong

An accurate knowledge of the atmospheric refractivity is important for the study of light wave propagation, and the refractive index of water vapor plays an important role in the atmospheric refractivity. The line-transitions of water vapor in the latest HITRAN (high resolution transmission) database are used to calculate the refractive index of standard water vapor for wavelengths between 0.3 μm and 20 μm. Before the calculation, a pseudo-spectral is constructed from the measured data to represent the UV resonances and photo-ionization continuum with nonlinear least square method, since the HITRAN database does not provide a line-transition in UV bands. Calculation results show that strong absorbance by water vapor occurs at wavelengths around 2.9 μm and 7 μm in the mid-infrared. Then a simple dispersive formula at wavelengths from 0.3 μm to 20 μm for standard water vapor is given, where the Gross line shape is used. Finally the new dispersive formula is compared with the previous formulae against measurements of refractive index for wavelengths in visible bands and around 3.4 μm, 10.6 μm, which is in good agreement with the measuremental data.

Jan. 01, 1900
  • Vol. 32 Issue s1 101001 (2012)
  • Wang Xiang, and Zhang Yixin

    Imaging channel slant factor, the atmospheric turbulence of power spectral index of non-Kolmogorov, the light source spatial coherence (Gaussian-Schell beams) and lateral dimensions of the light source of the ghost imaging have been studied. Based on the optical coherent theory, the extended Huygens-Fresnel pricinple and the turbulence model of non-Kolmogorov, Z-tilt aberration correction of the atmospheric channel of slant channels turbulence of the theoretical models of ghost imaging with Gaussian-Schell beams have been analyzed and derived. By the numerical computations of the model, the result shows that the nearer the object is to illuminant plane, the better the quality of ghost imaging is. The undersized illumination light source will cause the quality decline of ghost imaging and the image quality of the object illuminated by the incoherent light are worse than that of illuminated by partially coherent light.

    Jan. 01, 1900
  • Vol. 32 Issue s1 101002 (2012)
  • Tu Yi, Yang Jian, Sun Zhiwei, and Jin Liang

    The cooperating beacons assembled on the aircrafts, can solve the remote high-accuracy tracking problem of the visible light CCD, in order to make the detection system detect the target as soon as possible. Taking radiometry as a standard and embarking on target signal, background signal difference and noise ratio of detector, the relationship between monochrome LED beacons and minimum detection power of visible light CCD, and the relationship between spot size and atmospheric transmissivity are analyzed. Furthermore, the light power of different monochrome LED beacons with fixed operating distance of detector is calculated. And the correctness of the calculation results is validated by observing the effect of ground test of CCD imaging.

    Jan. 01, 1900
  • Vol. 32 Issue s1 104003 (2012)
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