Patent ID: 8705041

Claim:
An optical probe comprising: an optical axis; at least one optical source for illuminating light along the optical axis and providing an input light beam; a first beam splitter intersecting with the optical axis and configured to split the input light beam from the at least one optical source into a first beam and a second beam, the first beam being directed in a first direction along the optical axis to a reference surface intersecting the optical axis and the second beam being directed in a second direction along the optical axis to a specimen that intersects the optical axis, wherein the first direction and the second direction are different; a first lens interposed between the reference surface and the first beam splitter and intersecting the optical axis, wherein the first lens provides a reference path for the first beam: and a second lens interposed between the first beam splitter and the specimen and intersecting the optical axis, wherein the second lens provides a test path for the second beam; and wherein the first lens and the second lens are attached to the first beam splitter.