Enhancement of in-vitro cellular structure morphology imaging using multiwavelength confocal endoscopic scanner

Abstract

Optical imaging is crucial for cell examination, but its instruments' bulky optics limit their flexibility, and a single wavelength provides limited sample information. This paper presents a fibre cantilever-based endoscopic scanner for multiwavelength reflectance confocal microscopy. The scanner utilises the dual-core fibre cantilever to produce Lissajous scans while accommodating two distinct wavelengths. Coloured surfaces were imaged at wavelengths of 520 nm, 635 nm and 850 nm, and verified with a colour chart and reflectance spectroscopy. Blue ink-stained plant stem cross-section samples were also imaged and compared. Furthermore, the scanner performed structure morphology imaging on cellular samples. The 520 nm and 635 nm wavelengths create low- and high-contrast images respectively, while the 850 nm wavelength delivers a sharper image while also capturing the surface profile of the target sample. The findings demonstrated the endoscopic scanner’s capability to extract information based on different wavelengths, providing a more diverse view of the sample and enhancing the surface profile. Using 635 nm and 850 nm, the reconstructed images have a contrast enhancement of 67.9% and 90.8% respectively from 520 nm. The smallest feature size measured on the cellular sample is 5 µm. The endoscopic scanner has the potential to study microfluidic and cell morphology.