Delivering targeted color light through a multimode fiber by field synthesis

Area of Science:

• Optics and Photonics
• Biomedical Engineering
• Endoscopic Imaging

Background:

• Multimode fibers (MMF) are emerging as viable tools for endoscopic imaging due to wavefront shaping advancements.
• Previous MMF imaging studies were restricted to monochromatic or narrow-bandwidth polychromatic light.
• The need for full-color imaging in endoscopy necessitates multi-wavelength light delivery through MMF.

Purpose of the Study:

• To demonstrate the delivery of targeted, full-spectrum visible light through a multimode fiber.
• To enable color imaging capabilities in endoscopic applications using MMF.

Main Methods:

• Mixing three primary colors (red, green, blue) using a single spatial light modulator (SLM).
• Generating an optimal phase map via field synthesis (FS), where each SLM pixel contributes to all colors.
• Comparing FS performance against the spatial segmentation method through theoretical and numerical analysis.

Main Results:

• Field synthesis (FS) significantly outperformed the spatial segmentation method for multi-wavelength light delivery.
• Color composition adjustment allowed for color switching at video frame rates.
• Successful demonstration of targeted color light delivery through MMF.

Conclusions:

• Field synthesis enables efficient, full-spectrum color light delivery through multimode fibers.
• This technique overcomes limitations of previous MMF imaging approaches.
• The developed method is a significant step towards realizing color imaging in MMF-based endoscopy.