Patent ID: 8681331

Claim:
A microscopy or micro-spectroscopy system comprising: a first light source for providing a first illumination field at a first optical frequency ω 1 ; a second light source for providing a second illumination field at a second optical frequency ω 2 ; a modulator for modulating a property of the second illumination field at a modulation frequency f of at least 100 kHz to provide a modulated second illumination field; an optical assembly including focusing optics and an optical detector system, said focusing optics for directing and focusing the first illumination field and the modulated second illumination field through an objective lens toward the common focal volume along an excitation path; and said optical detector system including at least one optical detector for detecting a detected first field intensity of the first illumination field that is back-scattered within a sample, wherein said optical detector provides an electrical signal representative of the detected first field intensity, and said optical detector is located proximate a portion of the excitation path; and a processor for detecting a modulation at the frequency f of the electrical signal due to non-linear optical interaction within the common focal volume.