Research On Polarization Of Scattered Light From Bubbles In Water

The torpedo of accurate guiding is becoming the main weapon in the modern marine war, but with anti-guidance technical development, microwave guidance technique and sonarguidance technique has gradually been out of action. So research and developing a new guidance technique are very important for guided weapon. Based on light scattered effect of bubbles in water, the light torpedo homing is considered as the most likely suitable for the need for the modern naval battle technique. The character of ship wake is decided by the mount moving bubbles in it.Polarization properties as one of the most important features of scattered light, compared to natural light decided only by the intesity, can provide more information including polarization direction. So studying on polarization of scattered light from bubbles in water can help us research on the Scattered characteristics more deeply. Based on this, polarization properties of scattered light from bubbles in water are systematicly studied in this paper, the main research contents are as follows:Firstly, Mie Scattered Phase Functions (SPFs) of bubbles including single bubble and bubble films are calculated with different polarizations. The Scattered properties of ship wakes are investigated under polarized state based on the calculation, and three-dimension graphs of scattering angle-polarized angle-the scattered intensity are given based on the calcalation. Results of the investigation show that the distribution tendencies of SPFs by ship wakes are basically similar with light under different polarized states. The distribution properties are in great difference with scattering angle between 80 and 140 degrees in which different SPF curves are clear and distinguishable easily.Second, Single-scattering Mueller matrices expression based on Stokes vectors of the forward scattered light are derived when a narrow pencil like beam is perpendicular to the surface of the bubbles in water. Using only Mie theory of light scattering by sphere, the properties distribution pattern of forward-scattering Mueller matrix belonging to bubbles (FSMMBB) and the correlation with bubble number density, bubble diameter are discussed.Some important conclusions are as follows:M11 and M44 of FSMMBB for bubbles have no clear change with different azimuths. Distributions of the elements changing with different azimuths are in accordance with the law of sine shocks,and the elements of FSMMBB decay with polar radius exponentially; M11,M44and their amplitudes change with different azimuths, increase with radius rising. Maximums of those elements occur at bubble number density of 108m-3. The characteristics between elements are opposite with different number densities around sides. Besides intensity, information of phase reversal with bubble radius as well as number density changing is reasonably contained in M12and M13.Finally, by using the Monte Carlo program for light propagation with polarization, which could calculate the stokes vectors of Scattered light from bubbles in water,a deep research on the polarization properties of forward scattered light from bubble films are studied with line and the circular polarized light entrancing. The results show that:Spatial distributions of the degree of polarization of forward scattered light (DOPFSL) from bubble films have the property of azimuth selceting, and DOPFSL decrease with the distance increasing from the point of incidence. The forward scattered light is elliptically polarized light, and the rotary direction of the elliptical polarized light is ralated to the azimuth selceting of linearly polarized light and the rotary direction of circular polarized light. DOPFSL decrease sensitively with the scattered coefficient scattered coefficient increasing, and the same, DOPFSL of the circle of polarized light is always higher than line polarized light.