Hollow-fiber Raman probe

Figure 15 shows the Raman spectra of the rat stomach measured in vivo with a hollow-fiber Raman probe. Although the Raman signals are much lower than the fluorescence background (Fig. 15a), the signal peaks clearly appear when the background is numerically subtracted (Fig. 15b). This is the first in vivo detection of the Raman spectra from the stomach of a hving animal.

Fig. 15 Raman spectra of rat stomach measured in vivo with hollow-fiber Raman probe...

Abstract This chapter reviews the development of optical fiber probe Raman systems and their applications in life science and pharmaceutical studies. Especially, it is focused on miniaturized Raman probes which open new era in the spectroscopy of the life forms. The chapter also introduces the important optical properties of conventional optical fibers to use for Raman probes, as well as new types of optical fiber and devices, such as hollow optical fibers and photonic crystai fibers. 

Yan H, Gu C, Yang C et al (2006) Hollow core photonic crystal fiber surface enhanced Raman probe. Appl Phys Lett 89 204101... 

Abstract Thin and flexible probes made with hollow-optical fibers may be useful for remote spectroscopy. Experimental results showed that these probes are useful for endoscopic measurements of infrared and Raman spectroscopy. A hollow-fiber probe has been used for remote FT-IR spectroscopy in the form of endoscopic measurement of infrared reflectometry spectra inside the body. This measurement was made possible by the hollow-fiber probe s flexibility, durability, nontoxicity, and low transmission loss. A hoUow-fiber probe with a ball lens at the end works as a confocal system for Raman spectroscopy. It can thus detect the molecular structure of biotissues with a high signal-to-noise ratio. Owing to their small diameter, the probes are useful for in vivo, noninvasive analysis using a flexible endoscope. 

Keywords Hollow-optical fibers Infrared spectroscopy Raman spectroscopy Endoscopes ET-IR Raman probes... 

Fig. 13 Intensity of Raman signal from silicon measured by using a hollow-fiber probe with a ball lens...

Fig. 14 Raman spectra of rat stomach measured ex vivo using hollow-fiber probe and Raman microscope...

Figure 14 shows the Raman spectrum of a rat stomach measured ex vivo using the hollow-fiber probe. A spectrum taken by using a Raman microscope is also shown for comparison. The excitation power was 29 mW, and the exposure time for the measurement was 60 s. Although Raman peaks of the sapphire-ball lens at 630... 

Harrington JA (2003) Infrared fibers and their applications. Chap 1. SPIE, Bellingham, WA Katagiri T, Komachi Y, Hattori Y, Matsuura Y, Miyagi M, Tashiro H, Sato H (2006) Hollow-optical fiber probe for confocal Raman endoscopy. Proc SPIE 6083 60830 Komachi Y, Sato H, Aizawa K, Tashiro H (2005) Micro-optical fiber probe for use in an intravascular Raman endoscope. Appl Opt 44 4722-4732... 

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