Patent ID: 7706646

Claim:
A device for delivering light to and collecting light from a target, comprising: a sheath structured to include a hollow channel along a sheath longitudinal direction, the sheath having a proximal end configured to receive input polarized light and a distal end configured to export the input polarized light as probe light outside the sheath to a target; a polarization maintaining (PM) fiber movably placed inside the hollow channel of the sheath and structured to exhibit a first principal polarization direction and a second, orthogonal principal polarization direction, both perpendicular to a longitudinal direction of the PM fiber; an optical probe head located inside the sheath and engaged to a distal end of the PM fiber with a fixed orientation relative to the first principal polarization axis of the PM fiber to receive the input polarized light from the PM fiber, the optical probe head operable to direct the probe light polarized in the first principal polarization direction to exit the optical probe head at a first exit angle with respect to the sheath longitudinal direction and the probe light polarized in the second principal polarization direction to exit the optical probe head at a second, different exit angle with respect to the sheath longitudinal direction, respectively; and a rotation mechanism coupled to the optical head and operable to rotate the optical head inside the sheath about the sheath longitudinal direction to change a direction of light existing the optical probe head at the first exit angle and at the second exit angle.