Broadband imaging optical fiber based on multicomponent glasses for endoscopy in the VIS-NIR band

The development of multimodal diagnostic techniques requires advanced tools for in vivo imaging. This paper presents the design, fabrication, and optical characterization of a broadband multicore optical fiber, adapted to operate in the visible (VIS) and near-infrared (NIR) wavelength ranges. A fiber structure comprising more than 13,000 cores within a 400 µm-diameter cross-section was fabricated from multicomponent glasses using the stack-and-draw technique. Based on measurements and analytical calculations, the fiber's numerical aperture (NA) was determined to be 0.53. Its transmission properties were characterized in the 400-1100 nm spectral range. The experimental results reveal a high image transmittance of up to 74.5% and an average attenuation of 1.40 dB, demonstrating the potential of this structure for ultra-thin fluorescent and coherent endoscopes.