A miniaturized fiber-coupled terahertz endoscope system.

Area of Science:

• Biomedical Optics
• Terahertz (THz) Spectroscopy
• Medical Imaging

Background:

• Miniaturized endoscopic systems are crucial for minimally invasive medical diagnostics.
• Terahertz (THz) technology offers unique capabilities for non-ionizing imaging and spectroscopy of biological tissues.
• Existing THz systems often lack the necessary form factor for deep tissue or internal organ examination.

Purpose of the Study:

• To design, fabricate, and characterize a miniaturized optical fiber-coupled terahertz (THz) endoscope.
• To evaluate the performance of the THz endoscope in reflection mode, comparing it to conventional THz time-domain spectroscopy.
• To assess the feasibility of using the THz endoscope for in-vivo measurements of human tissues.

Main Methods:

• Development of a miniaturized THz endoscope system using a photoconductive generator and detector.
• Integration of the THz components with a mode-locked Ti:sapphire laser.
• Characterization of the endoscope's signal-to-noise ratio and frequency spectrum.
• Feasibility testing involving THz reflection measurements from oral tissues, palm skin, and water.

Main Results:

• The optical fiber-coupled THz endoscope achieved a high signal-to-noise ratio and a broad frequency spectrum comparable to conventional THz systems.
• The endoscope head, measuring (2 x 4 mm) x 6 mm, is sufficiently small for insertion into the human body.
• THz measurements revealed that the absorption and refractive indices of the mouth and tongue tissues were similar to water.
• Palm skin exhibited lower absorption and refractive indices compared to water.

Conclusions:

• The developed miniaturized THz endoscope is a viable tool for internal biomedical imaging and spectroscopy.
• The system's compact size and high performance open possibilities for new diagnostic applications.
• THz endoscopies can differentiate tissue properties, offering potential for disease detection and characterization.