A model of degree of scattering polarization for oil spilling

Oil slicks often show uncertain surface roughness and Fresnel reflection parameters. Consequently, differentiating oil spilled on the seawater in these areas using optical sensors is a challenge. Therefore, the optical mechanism of the oil film has been studied by the Maxwell equation. It is found that the polarization characteristics of the oil slicks can help us to overcome this problem. According to the Fresnel formula, the scattering coefficient and scattering rate of the homogeneous oil film have been deduced, and the phase difference of the scattering electromagnetic wave has also been calculated to verify the accuracy of the model. The parameter, a degree of scattering polarization, has been derived to identify the oil slicks on the sea wave. It depends on accurately knowing the Stokes parameter for the reflected light, and varies with the refractive index of the surface layer and viewing angles. The actual spilled oil has been measured by this model, and the oil film can be accurately identified at various angles. These preliminary results suggest that the potential of multi-angle polarization measurement of ocean surface needs further researches.

Reflection and Refraction

We explore the propagation of a light wave when the propagation velocity of the medium change in a discontinuous way. We rely only on the wave properties of light to obtain the fundamental laws of reflection and refraction and use boundary conditions developed for Maxwell’s Equations to obtain the Fresnel formula for the amount of light transmitted or reflected. We alos turn to the more fundamental Principle of Fermat to derive the two laws but limit detailed examination to the law of reflection. We look at the effects of polarization on reflection and consider the physical cause of Brewter’s angle. The topic of total reflection is covered in more detail because of its importance inf fiber optics. We have ignored any loss in the propagation of light but now we examine reflection from metals and discover the effects on reflection of using a protective coating on metals

Polarizers

Introduction to how to measure polarization and the degree of polarization, The various physical processes used to control polarization including: absorption, reflection, interference, and birefringence. An explaination of the operation of a wire grid and its molecular equivalent, a polaroid plastic are given. Fresnel formula for reflection is used to calculate the Stokes component of the reflected light. A brief introduction to the concept of birefringence is given and the various designs of birefringent prism polarizers are listed with their advantanges and shortcomings. A sample design of a prism polarizer is given. Quarter wave and half wave retarders and their use are discussed. An optional section is devoted to optical activity and the use of chiral measurements in chemistry and drug manufacturing are discussed.

‘Aether drag’ in a transversely moving medium

A previous measurement of the Fresnel ‘aether drag’ in a transversely moving medium (Jones 1972) has been repeated with improved accuracy to find whether the original Fresnel formula should be modified by a dispersion term as was shown by Lorentz and Zeeman for the longitudinal drag. A formula derived by M. A. Player and by G. L. Rogers gives the transverse displacement of a beam of light passing through a medium of thickness t moving with transverse velocity v as vt ( n q — n q -1 )/ c rather than vt ( n g — n ^ -1 )/ c as given by the original Fresnel formula, where n q is the phase refractive index and n g is the ‘group refractive index.’ The present experiment gives results in accordance with the Player-Rogers formula rather than with the Fresnel formula or one in which the group refractive index alone is involved; it parallels what Zeeman found for the longitudinal case. The main improvement in experimental accuracy has come from recognition of errors in the method of calibration by optical micrometry.