Wavelength dependent characterization of a multimode fibre endoscope

Area of Science:

• Optics and Photonics
• Biomedical Imaging
• Materials Science

Background:

• Multimode fibers are emerging as miniature endoscopic probes for advanced imaging techniques.
• Non-linear microscopy using these probes faces bandwidth limitations affecting laser focusing and wavelength tunability.
• These limitations hinder the full potential of fiber-based endoscopic imaging systems.

Purpose of the Study:

• To investigate the bandwidth limitations in multimode fiber-based non-linear microscopy.
• To identify the key factors contributing to reduced imaging performance.
• To propose solutions for overcoming these limitations and enhancing imaging capabilities.

Main Methods:

• Characterization of imaging system bandwidth, including spatial light modulator (SLM) dispersion and fiber bandwidth.
• Demonstration of dispersion correction techniques for the off-axis hologram displayed on the SLM.
• Evaluation of a standard prism pulse compressor for material dispersion compensation.

Main Results:

• The imaging system's bandwidth is limited by both SLM hologram dispersion and the intrinsic bandwidth of the multimode fiber.
• Dispersion introduced by the SLM hologram can be effectively corrected.
• The selection of an appropriate fiber is critical for achieving optimal imaging performance.
• A standard prism pulse compressor adequately compensates for material dispersion in multi-photon imaging.

Conclusions:

• Fiber selection is paramount for successful non-linear microscopy with multimode fiber endoscopes.
• Dispersion management, including SLM hologram correction and pulse compression, is essential for high-fidelity imaging.
• These findings pave the way for improved fiber-based endoscopic imaging systems.