US 10,241,131 B2 · Method and apparatus for chemical and optical imaging with a broadband source

Abstract

Systems and methods that enable both spectroscopy and rapid chemical and/or optical imaging using a broadband light source. Broadband light sources may be advantageous for spectroscopy as they simultaneously illuminate a sample with a plurality of wavelengths and use interferometric techniques to determine a material response as a function of wavelength (or equivalently wavenumber). Some embodiments may enable the same radiation sources to be used to efficiently map the spatial distribution of chemical species or optical property variations. This may be achieved via selection of specific optical phase delays within an interferometer that are selected to maximize the contrast between different absorption bands or resonances within the sample. By optimally selecting specific interferometer phases it may be possible to construct images that substantially represent the material response to a specific wavelength excitation, without the necessity to obtain entire spectra at each sample location. This can provide orders of magnitude improvements in the measurement speed for required with a broadband source to provide compositional/optical property mapping.

Claims25

Dependent claims

A method of measuring an optical property of a sub micrometer region of a sample comprising the steps of:

a. Interacting a probe tip of the probe microscope with a region of the sample;
b. Illuminating the sample with a beam of light from at least one broadband radiation source;
c. Interfering a reference beam with at least one of (i) light scattered from the region of tip/sample interaction and (ii) light incident on the tip/sample interaction region;
wherein the reference beam has an adjustable phase;
d. At least one of selecting or determining a limited number of reference phases that produce substantially different optical responses for at least two different wavelengths, wherein the limited number of reference phases is less than 10;
e. Measuring a signal indicative of the optical property of the sample at only the limited number of reference phase values;
f. Constructing at least one image of the optical property of the sample at a plurality of positions on the sample;
and
wherein the limited number of reference phases comprise a reference phase in which one of the at least two different wavelengths has maximum constructive interference and another of the at least two different wavelengths has maximum destructive interference.

6 more elements

Dependencies are inferred from the claim text.

Method and apparatus for chemical and optical imaging with a broadband source

Life of this patent

Method and apparatus for chemical and optical imaging with a broadband source

Life of this patent

Abstract

Claims25