Patent ID: 6876801

Claim:
An immersion probe for use in Raman spectroscopy which includes: an extended immersion tip that includes an internally reflecting lightguide; first optical element for collecting laser radiation emerging from a first optical fiber and directing it, after subsequent reflections, into the end of said internally reflecting lightguide in such a way that it is as nearly collimated as possible consistent with substantially all of the radiation entering the lightguide; second optical element for collecting Raman shifted radiation emerging from said internally reflecting light guide and focusing it on a second optical fiber in such a way that the size and shape of the image of the end of the lightguide matches the size and shape of said second optical fiber; reflecting means for redirecting the beam formed by said first optical element so that its axis is anti-parallel to and coaxial with the axis of the Raman shifted radiation emerging from said lightguide.