Patent ID: 7075630
Filing Date: 2006-07-11
Classification: G01B,G01N,H01L

Abstract:
1. A system for measuring a specular reflectivity of a light signal, comprising: a first light source for transmitting a first incident light signal toward a first surface of a first object in a first plane of incidence wherein said first object is at least on of a magnetic disk, a silicon wafer and a transparent glass substrate; a first polarization splitter for separating, from a first reflected light signal that has reflected off the first surface of said first object, a first mixed reflected polarized light signal component having a first phase and a second mixed reflected polarized light signal component having a second phase different from said first phase, wherein said first mixed reflected polarized light signal component comprises both P-polarized and S-polarized light relative to the plane of incidence of said first incident light signal, and wherein said second mixed reflected polarized light signal component comprises both P-polarized and S-polarized light relative to the plane of incidence of said first incident light signal; a first detector for detecting a first intensity of said firms mixed reflected polarized light signal component; a second detector for detecting a second intensity of said second mixed reflected polarized light signal component; a first spatial filter positioned to block a light signal reflected from a second surface of said first object from reaching said first and second detectors; and a first specular reflectivity determinator for determining a first specular reflectivity based upon said first and second intensitities.