Fourier Transform Spectrometr

A method of providing a Fourier Transform (FT) spectroscopy comprising;

• providing an excitation light signal;
• separating the excitation light signal into a first spectroscopic excitation portion and a second metrology portion;
• directing the first spectroscopic excitation portion of the excitation light signal toward a sample;
• directing the second metrology portion of the excitation light signal toward an interferometer beam splitter;
• separating the second metrology portion of the excitation light between a first interferometer mirror and a second interferometer mirror;
• moving at least one of the first and second interferometer mirrors to generate an interference pattern between the separated portions of the second metrology portion of the excitation light signal;
• directing reflected portions of the metrology portion of the excitation light signal from the first interferometer mirror and the second interferometer mirror toward a first metrology detector;
• separating the spectroscopy signal between the first interferometer mirror and the second interferometer mirror;
• moving at least one of the first and second interferometer mirrors to generate an interference pattern between the separated portions of the spectroscopy signal;
• and
• directing reflected portions of the spectroscopy signal from the first interferometer mirror and the second interferometer mirror toward a second spectroscopic detector.

A method of correcting a signal from an interferometer of an FT Spectrometer comprising:

• determine a number of peaks in a metrology signal interferogram;
• determine an average frequency of peaks in the metrology signal interferogram based on the number of peaks;
• generate a theoretical interferogram with a sinusoidal pattern based on the frequency;
• locate a plurality of data points in metrology signal interferogram and in the theoretical interferogram;
• and
• adjust a plurality of distances corresponding to the plurality of data points in the metrology signal interferogram to match the theoretical interferogram;
• and

A Total Spectroscopy method comprising:

• Excite a sample using at least one light source, such as using a laser light source to produce a Total Spectroscopy signal comprising Raman scattering, fluorescence, and absorption components. In another embodiment, the at least one light source may comprise a laser light source used to produce Raman scattering and fluorescence, and a relatively weak broadband source to produce an absorption component.
• obtain a total spectroscopy signal comprising at least a Raman spectroscopic component, a fluorescence spectroscopic component, and an NIR absorption component forming an integrated total spectroscopy signal;
• compare the total spectroscopy signal to a library of discrete total spectroscopy signals and respective corresponding materials and/or compare the total spectroscopy signal to a standard intensity or absorption to produce a quantitative response;
• and
• identify at least one of the corresponding qualitative or quantitative response based on the total spectroscopy signal.