Patent ID: 6560478
Filing Date: 2003-05-06
Classification: A61B,G01J,G01N

Abstract:
A method of examining an object, said method comprising the steps of:(a) irradiating the object with a first pump beam at a first wavelength, whereby the object produces a spontaneous Raman emission at a second wavelength; (b) substantially simultaneously with step (a), irradiating the object with a first probe beam at a third wavelength, whereby the intensity of said first probe beam emitted from the object at said third wavelength increases if said third wavelength is equal to said second wavelength; (c) detecting the intensity of said first probe beam emitted from the object at said third wavelength following steps (a) and (b), whereby an increase in intensity of said first probe beam at said third wavelength indicates the presence of a Raman mode for the object at said first wavelength; (d) irradiating the object with a second pump beam at a fourth wavelength, whereby the object produces a spontaneous Raman emission at a fifth wavelength, said fourth wavelength not being equal to said first wavelength; (e) substantially simultaneously with step (d), irradiating the object with said first probe beam at said third wavelength, whereby the intensity of said first probe beam emitted from the object at said third wavelength increases if said third wavelength is equal to said fifth wavelength; and (f) detecting the intensity of said first probe beam emitted from the object at said third wavelength following steps (d) and (e), whereby an increase in intensity of said first probe beam at said third wavelength indicates the presence of a Raman mode for the object at said fourth wavelength; (g) wherein said first pump beam and said second pump beam are generated using a wavelength-tunable laser.