Patent ID: 8804117

Claim:
Device ( 100 ) for detecting a resonant nonlinear optical signal induced in a sample ( 105 ) of a type comprising a resonant medium ( 41 ) and a non-resonant medium ( 42 ) forming an interface ( 43 ), the device comprising: an emission source ( 801 ) of at least one first excitation light beam, called a pump beam, at a first given angular frequency ω p for the excitation of a resonant medium of a sample of the given type, an optical detection module ( 106 ) for detecting a nonlinear optical signal resulting from the interaction of said pump beam with an axial interface between the resonant and non-resonant media of the sample, in at least two symmetrical directions ({right arrow over (k)}, {right arrow over (k)}′) about the optical axis of said incident pump beam incident in the sample, and a processing unit ( 125 ) for processing the signals thus detected along the at least two symmetrical directions, allowing the difference in detected signals to be obtained, the resulting difference signal being characteristic of a vibrational or electronic resonance of the resonant medium.