SUPPRESSION OF FLUORESCENCE INTERFERENCE VIA WAVELENGTH SHIFT-KEYED RAMAN-SPECTROSCOPY USING AN ARGON ION LASER AND ACOUSTOOPTIC TUNABLE FILTER

A wavelength shift-keyed (WSK) Raman spectrometer with argon ion laser excitation, acousto-optic tunable filter (AOTF) wavelength modulation , and synchronous photon counting detection has been developed. It has been demonstrated that this novel approach to wavelength modulation s pectroscopy results in suppression of unwanted fluorescence background while giving a substantial increase in signal-to-background over non modulation techniques. The relatively low cost, lack of complexity, an d durability of the described system increases the utility of shift-ke yed Raman spectroscopy to a broader base of users and 'real world' app lications. (C) 1998 Elsevier Science B.V. All rights reserved.