Super-Achromatic Rapid Scanning Microendoscope for Ultrahigh-Resolution OCT Imaging

Area of Science:

• Biomedical optics
• Medical imaging technology
• Microscopy

Background:

• Microendoscopy is vital for high-resolution internal organ imaging using optical coherence tomography (OCT).
• Conventional gradient index (GRIN) lenses present limitations in achieving optimal resolution and imaging speed for microendoscopic OCT.
• Advancements in microlens technology are crucial for enhancing the capabilities of OCT-based microendoscopes.

Purpose of the Study:

• To develop an achromatic compound microlens for microendoscopic OCT applications.
• To engineer a rapid scanning microendoscope system incorporating the novel microlens.
• To evaluate the imaging performance, specifically resolution and speed, of the developed microendoscope system.

Main Methods:

• Design and fabrication of an achromatic compound microlens.
• Integration of the microlens into a rapid scanning microendoscope system.
• Performance evaluation using ultrahigh-resolution optical coherence tomography (UHR-OCT) with a broad spectrum bandwidth light source.
• Comparative analysis with conventional GRIN lens-based endoscopes and bench-top systems.

Main Results:

• The developed microendoscope achieved an ultrahigh transverse resolution of 4 μm and an axial resolution of 2.2 μm.
• Real-time UHR-OCT imaging was demonstrated at an imaging speed of approximately 1220 lateral scans/s.
• The compound microlens-based endoscope showed superior performance in imaging biological tissues compared to GRIN lens-based systems.
• Image quality was comparable to slow, high-performance bench-top UHR-OCT systems.

Conclusions:

• The achromatic compound microlens enables a significant advancement in microendoscopic OCT technology.
• The rapid scanning microendoscope offers unprecedented speed and resolution for in vivo imaging.
• This technology holds promise for improved diagnostics and research in internal luminal organs.