Analysis of Light Scattering Properties about Dent Nanoparticles upon Wafer

The light scattering properties of the dent nanoparticles upon wafers is discussed in this paper. Taking the advantage of the Bobbert-Vlieger (BV) theorem, the scattering model between wafer and dent nanoparticles is established. The scattering process is analyzed and the scattering coefficients are derived by using of the vector spherical harmonic function. The differential scattering cross section (DSCS) of the dent nanoparticles upon the wafer is calculated which is compared with the extended Mie method proved the validity of the method and the influences of the dent position, dent scale and scattering angle on the DSCS are analyzed numerically in details. The result is shown that the effect of the dielectric is smaller than the metal. Therefore, the material of the defect and the shape can be extracted by calculate the DSCS, which provide strong theoretical foundation to the nondestructive detector engineer.

The Angle Distribution of the Spheroid Particle upon Optical Surface

The angle distribution of the spheroid particle upon optical surface is discussed in this paper. Taking the advantage of the Bobbert-Vlieger (BV) theorem, the scattering model between optical surface and spheroid particles is established. The scattering process is analyzed and the scattering coefficients are derived by using of the vector spherical harmonic function. The differential scattering cross section (DSCS) of a spheroid particle upon the optical surface is calculated which is compared with the Discrete Sources Method (DSM) proved the validity of the method and the influences of the incident angle and scattering angle on the DSCS are analyzed numerically in details. The results show that the influence of the incident angle on the scattering intensity is less at the smaller scattering angle, which can be concluded that the influence of the incident angle is more serious to the back scattering .The polarization effect and back scattering effect become weaker and weaker with the increase of the incident angle, which provide strong theoretical foundation to the nondestructive detector engineer.

A Review of Observational Helioseismology

There have been several excellent reviews of observational helioseismology in recent years. These include the reviews by Harvey (1988), Libbrecht (1988), and van der Raay (1988) presented at a recent conference in Tenerife. The present effort will concentrate on the progress made on solar rotation recently.The Sun is a resonant cavity that supports many (~ 107) modes of oscillation. The modes that are most easily observed are the acoustic or p-modes. The eigenfunctions for these modes are:fnl(r) is the radial part of the separable eigenfunction where r is the radial coordinate measured from the center of the star. n is the number of radial nodes in the eigenfunction. Ylm (θ,ϕ) is the spherical harmonic function, where θ is the colatitude and ϕ is the longitude. The spherical harmonic degree l is the number of nodes of the spherical harmonic measured along a great circle that makes an angle with the equator. The azimuthal order m is the number of nodes around the equator. The frequency of the eigenmode, vnlm, depends on the mode. Much of our information derived about the solar interior from helioseismology comes from the measurement of these frequencies.