Abstract

The rapidly expanding field of research into tissue optics has introduced the need to make measurements of the refractive index of tissue. For example, theoretical calculations done on the transport of light in turbid material frequently must take account of boundaries and interfaces where the index changes. The use of traditional methods of measurement is difficult due to the highly absorbing and scattering nature of the tissue medium. A simple and rapid method for finding the refractive index of mammalian tissue is presented. Application to nonbiological materials is also possible. This method utilizes the light piping properties of standard fiber optics. The tissue to be measured replaces the cladding of the fiber, and the output of the fiber optic produces an angularly dependent intensity pattern, which is a function of the refractive index. Resultant values for several mammalian tissues (bovine, porcine, and human) have been determined at 632.8 nm. With few exceptions, for tissues at this wavelength, nwas in the 1.38–1.41 range. Measurements were also made on the effects of tissue hydration and lipid content.

© 1988 Optical Society of America