Combined fluorescence and reflectance spectroscopy

An apparatus for measuring fluorescence and spatially resolved reflectance spectra of a sample, comprising:

• a light source;
• a monochromator in optical communication with said light source;
• a fiber optic probe in optical communication with said light source and with said monochromator, said probe comprising a plurality of fluorescence excitation and collection fibers in spaced relation and surrounded at least partially by a plurality of reflectance collection fibers in spaced relation with a reflectance illumination fiber;
• an imaging spectrograph in optical communication with said plurality of fluorescence collection fibers and with said plurality of reflectance collection fibers;
• and
• a detector in optical communication with said imaging spectrograph.

A method for combined fluorescence and spatially resolved reflectance spectroscopy of a sample, comprising:

• providing a reflectance illumination fiber, a fluorescence excitation fiber, a fluorescence collection fiber, and a reflectance collection fiber that define a fiber optic probe comprising a center section and an outer section, said fluorescence excitation fiber and said fluorescence collection fiber being positioned in said center section, and said reflectance illumination fiber and said reflectance collection fiber being positioned in said outer section;
• directing radiation to said sample with said fluorescence excitation fiber;
• collecting radiation from said sample with said fluorescence collection fiber;
• directing said radiation from said sample to an imaging spectrograph and a detector;
• illuminating said sample with said reflectance illumination fiber;
• collecting reflected light from said sample with said reflectance collection fiber;
• and
• directing said reflected light from said sample to an imaging spectrograph and a detector.

A method for combined fluorescence and spatially resolved reflectance spectroscopy of a sample, comprising:

• providing a probe comprising a plurality of fluorescence excitation and collection fibers in spaced relation surrounded at least partially by a plurality of reflectance collection fibers in spaced relation with a reflectance illumination fiber;
• directing radiation to said sample with a fluorescence excitation fiber;
• collecting radiation from said sample with a fluorescence collection fiber;
• directing said radiation from said sample to an imaging spectrograph and a detector;
• illuminating said sample with a reflectance illumination fiber;
• collecting reflected light at a plurality of collection positions from said sample with said plurality of reflectance collection fibers arranged in spaced relation;
• directing said reflected light from said sample to an imaging spectrograph and a detector to produce spectral data;
• pre-processing said data;
• and
• reducing a dimension of said data using principal component analysis.