Abstract: A modulation method comprising steps of: a) generating a first signal having a first train of short pulses having a first frequency, and a second signal having a second train of short pulses having a second frequency, wherein each of the signals are associated with a negative or positive sign; b) maintaining a narrow frequency difference between the frequencies; c) imposing chirped modulation on each of the signals to achieve a desired spectral resolution, such that each signal is associated with a chirp having a first sign and a second sign; and d) switching between the signs for each signal over a frequency range, and detecting for each frequency of said frequency range, a spectral response resulting from a transfer of said modulation between the signals wherein the chirp sign of each of the signals is different, thereby obtaining hyperspectral data of said spectral response over said frequency range.

Abstract: A method of imaging a sample containing a target mineral species is provided. The method includes probing the sample with a pump beam and a Stokes beam having a tunable frequency difference, and detecting an optical response of the sample resulting from a transfer of said modulation between the pump beam and the Stokes beam. The probing is scanned spatially and spectrally, thereby obtaining hyperspectral data. Correlation with a known Raman resonance of the mineral species and with anon Raman-resonant contribution to said optical response allows building an image of the sample mapping different species within the sample.

Abstract: A method of imaging a sample containing a target mineral species is provided. The method includes probing the sample with a pump beam and a Stokes beam having a tunable frequency difference, and detecting an optical response of the sample resulting from a transfer of said modulation between the pump beam and the Stokes beam. The probing is scanned spatially and spectrally, thereby obtaining hyperspectral data. Correlation with a known Raman resonance of the mineral species and with anon Raman-resonant contribution to said optical response allows building an image of the sample mapping different species within the sample.