Use of liquid core waveguides for long pathlength absorbance spectroscopy: Principles and practice

摘要

For more than two decaldes liquid core waveguides (LCWs) have been used to enhance the sensitivity of spec- troscopic absorbance measurements (e. g., Stone 1992; Wa- terbury et al. 1997; Yao et al. 1998; Yao and Byrne 1999). The principal desired characteristic of liquid core wave- Guides is confinement of light rays within the LCW liquid Core when the refractive index (n) of the liquid core is higher Than the refractive index of the surrounding tubing. However, Not all light rays within an LCW are confined within the Liquid core, and different types of waveguides can differ con- Siderably in their waveguiding characteristics.