System and method for high sensitivity vibrational imaging with frequency modulation coherent anti-stokes Raman scattering analyses

摘要

A system is disclosed for detecting a nonlinear coherent field induced in a sample. The system includes optics, a modulation system, and a detector system. The optics are for directing a first electromagnetic field at a first frequency omega₁ and a second electromagnetic field at a second frequency omega₂ toward a focal volume such that a difference frequency omega₁-omega₂ is resonant with a vibrational frequency of a sample in the focal volume. The modulation system is for modulating the difference frequency omega₁-omega₂ such that the difference frequency omega₁-omega₂ is tuned in and out of the vibrational frequency of the sample of at a modulation frequency. The detector system is for detecting an optical field that is generated through non-linear interaction of omega₁ and omega₂ and the sample responsive to the modulation frequency.