Abstract

Spectroscopic studies on untreated nasopharyngeal biopsy specimens with various degrees of malignancy show that their fluorescence spectra are different from one another when photoexcitation wavelengths between 280 nm and 380 nm are used. A single peak at 340 nm is observed under the photoexcitation wavelengths from 280 ran to 310 nm. Figure 1 shows the typical spectrum when the tissues are excited by 280-nm light. Under excitation of 320 nm to 380 nm, a fluorescence peak at 440 nm and a small shoulder at 520 nm are observed.

© 1995 Optical Society of America