In-fiber common-path optical coherence tomography using a conical-tip fiber.

Area of Science:

• Biomedical Optics
• Optical Engineering
• Medical Imaging

Background:

• Common-path optical coherence tomography (CPOCT) minimizes dispersion and polarization mismatch by sharing optical paths.
• Conventional CPOCT requires an additional cover glass in the sample arm for a reference signal.
• This adds complexity and potential artifacts to the imaging system.

Purpose of the Study:

• To develop a simplified CPOCT technique by eliminating the need for an external reference cover glass.
• To utilize the back-reflected signal from a specialized fiber tip as the reference.
• To demonstrate the feasibility of this in-fiber CPOCT for biological tissue imaging.

Main Methods:

• A conical lens was fabricated directly onto an optical fiber tip using selective-chemical etching.
• This conical lens served dual roles: imaging lens and self-aligning reference plane.
• A Fourier-domain OCT system was employed to test the in-fiber CPOCT technique on biological samples.

Main Results:

• The conical lens-tip fiber successfully generated a reference signal without an additional cover glass.
• The technique demonstrated feasibility for imaging biological tissues.
• The in-fiber CPOCT system effectively reduced setup complexity.

Conclusions:

• The proposed in-fiber CPOCT technique offers a simplified approach to OCT imaging.
• This method holds significant potential for applications in endoscopic OCT.
• Further development could enhance its utility in minimally invasive medical procedures.