Sunshine Medical Instruments, Inc.

Mikhail Kouchnir

Vladimir Kupershmidt

Robert Petersen

A method and apparatus for analyzing a sample wherein at least two orthogonally polarized, intensity and phase modulated laser beams with different wavelengths and frequencies of intensity and phase modulation are directed onto the sample, and the signals derived from the laser beams which interact with the sample are synchronously demodulated to determine characteristics of the sample such as index of refraction, absorption coefficient and film thickness. A reference beam can be provided to correct for noise and drift.

Multiple wavelength polarization-modulated ellipsometer with

A method and an apparatus for the analysis of particles contained in a material, such as particles in a fluid or on a surface, such as the surface of a semiconductor, by two orthogonally polarized, intensity and phase modulated laser beams, wherein the detected scattered light is synchronously demodulated. The apparatus comprises a laser source producing a polarized laser beam, a state of polarization modulator, and a photoreceiver for detecting light scattered by particles at an angle to the incident light. A synchronous demodulator, such as a dual channel lock-in amplifier, separates the intensity and phase modulated portions of the scattered signals. A reference unit for detecting a non-scattered light produced by the sample to provide a reference is preferably provided, as well. The size, index of refraction and identity, of the particles, for example, can be determined.

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Palo Alto, CA, United States of America

Mikhail Kouchnir