US 5,285,261 A · Dual interferometer spectroscopic imaging system

Abstract

To obtain spectra from the surface of a sample, a first of a pair of interferometers includes a broadband radiation source and modulates the radiation at a frequency which is inversely proportional to wavelength. The modulated radiation impinges on the surface of interest where it is absorbed. The absorption of radiation causes the surface of the sample to expand. This change in dimension is then detected by a second interferometer which employs a monochromatic radiation source to measure the instantaneous distance between the sample surface and the second interferometer. The detection system of the second interferometer can be an imaging device such as a video camera to obtain the spatial distribution of chemical composition of the sample surface.

Claims12

Dependent claims

A system for creating images representing chemical composition of a sample surface based upon the electromagnetic absorption spectra thereof comprising:

a) a first interferometer means for irradiating a portion of a sample surface with a time modulated sample excitation beam having a plurality of frequencies, each frequency having an amplitude varying with time inversely according to its frequency;
b) a second interferometer means for detecting changes in distance over time between said sample surface and the second interferometer responsive to absorption by the sample of the broadband radiation beam generated by the first interferometer;
and
c) image formation means for calculation of absorption spectra of the portion of said sample surface from the detected changes in distance versus time between said sample surface and the second interferometer, for creating absorption spectra for portions of said sample surface from the detected changes in distance indicating chemical composition of said sample surface, and creating an image indicating chemical composition over the portions of said sample surface.

1 more element

Dependencies are inferred from the claim text.

Dual interferometer spectroscopic imaging system

Life of this patent

Dual interferometer spectroscopic imaging system

Life of this patent

Abstract

Claims12