Supercontinuum as a light source for miniaturized endoscopes

Abstract

Abstract:In this work, we have successfully implemented supercontinuum based illumination through single fiber coupling. The integration of a single fiber illumination with a miniature CMOS sensor forms a very slim and powerful camera module for endoscopic imaging. A set of tests and in vivo animal experiments are conducted accordingly to characterize the corresponding illuminance, spectral profile, intensity distribution, and image quality. The key illumination parameters of the supercontinuum, including color rendering index (CRI: 72%~97%) and correlated color temperature (CCT: 3,100K~5,200K), are modified with external filters and compared with those from a LED light source (CRI~76% & CCT~6,500K). The very high spatial coherence of the supercontinuum allows high luminosity conduction through a single multimode fiber (core size~400μm), whose distal end tip is attached with a diffussion tip to broaden the solid angle of illumination (from less than 10° to more than 80°).

Coherent Narrow-Band Light Source for Miniature Endoscopes

“…Our results show that the narrow band RGB laser module can be used as a high performance light source capable of more efficient light coupling due to its spatial coherence as compared to conventional LED and Xenon lamp sources. Moreover, the structure of the RGB laser module is far more compact and robust than that of the supercontinuum source used in a previous study [19]. Importantly, the use of the RGB laser in this work not only proved to be a cost effective and compact alternative light source for generating white light by multiplexing the red, green and blue laser wavelengths, but also paved the way for downsizing the overall diameter of the endoscope to an ultrathin scale of approximately 0.49 mm.…”

“…On the other hand, a spatially coherent light source coupled with a downsized light delivery system would greatly facilitate ultrathin endoscopes [18]. In a previous work, we have successfully implemented a supercontinuum laser with a high degree of spatial coherence as the light source for ultrathin endoscopy [19]. However, the inherent disadvantages such as high price, complexity in optimizing the illumination property and bulkiness prohibit supercontinuum from being practical for clinical treatment.…”

Ultraviolet-Extended Supercontinuum Generation in Zero-Dispersion Wavelength Decreasing Photonic Crystal Fibers

“…Supercontinuum (SC), which covers broad spectral band, offers an attractive optical source in diverse applications like metrology [1,2], biomedical imaging [3][4][5], and astronomy [6]. The SC in the ultraviolet-blue region is highly useful for fluorescence microscopy because many fluorescent molecules are excited in the wavelength range from ~600 to ~350 nm [7,8].…”