Bidirectional ellipsometry has been developed as a technique for distinguishing among various scattering features near
surfaces. The out-of-plane polarized light-scattering by metallic nanoparticles on wafer is calculated and measured.
These calculations and measurements yield angular dependence of bidirectional ellipsometric parameters for out-ofplane
scattering. The experimental data show good agreement with theoretical predictions for different diameter of gold
spheres. The results suggest that improvements for accuracy are possible to perform measurements of scattering features
from metallic nanoparticles. The polarization of light scattered by metallic nanoparticles can be used to determine the
size of nano-particulate contaminants on silicon wafers.
Photonic crystals have many potential applications because of their ability to control light-wave propagation. In this
paper, we have investigated PC-based optical waveguides implemented into wavelength division multiplexing (WDM)
systems. The WDM splitters based on a PC waveguide coupler with square lattice are proposed. Their wavelength
multiplexing properties are numerically investigated by using the finite-difference time-domain method. Rod-type
photonic crystal structures were fabricated in silicon by electron beam lithography and dry-etching techniques. The
WDM splitters were fabricated from two-dimensional photonic crystal waveguides. Transmission spectra were
calculated by using finite-difference time-domain method. The WDM splitters can be used in infrared region. Such an
approach to photonic element systems should enable new applications for designing components in photonic integrated
Laser encoders as an optical displacement measurement technique have many applications such as modern
manufacturing, scanning probe microscopy (SPM) and nanomanipulation. For the measurement scale down to the
nanometer range, the stability, sensitivity and tolerance to dynamic runout are the key issues for laser encoders. This
paper presents a novel laser encoder for sub-nanometer displacement measurement. It is based on optical heterodyne
interferometry and conjugate optics with a symmetric and quasi-common-path optical configuration. It offers high
stability, high resolution, low uncertainty displacement measurements and can break through the dynamic runout
problem in laser encoders. Experimental results reveal that the laser encoder can detect a displacement variation of 26
pm, and can thus be applied to sub-nanometer or even picometer positioning.