METHOD FOR DETECTING A RESONANT NONLINEAR OPTICAL SIGNAL AND DEVICE FOR IMPLEMENTING SAID METHOD

摘要

The invention relates to a method and device for detecting a resonant nonlinear optical signal induced in a sample (805) including a resonant medium (61) and a non-resonant medium forming an interface, the device including: a source (801) for emitting at least one excitation light beam of the resonant medium, referred to as the pump beam, at a first given pulse ?p, said pump beam being incident on the sample along an optical axis, and intercepting the sample at a given position of transverse interface between the resonant and non-resonant medium, a first optical module (803) for detecting the nonlinear optical signal resulting from the interaction of said beam(s) with the sample, means (813) for reflecting said excitation beam(s), the excitation beam(s) thus reflected intercepting said transverse interface at substantially the same position as the incident excitation beam(s), a second optical module (806) for detecting the nonlinear optical signal resulting from the interaction of said reflected excitation beam(s) with the sample, and a module (830) for processing the optical signals detected by said first and second detection modules, including the calculation of a difference in the detected signals, the difference being characteristic of a vibrational or electronic resonance of the resonant medium.