HIGH-FREQUENCY MODULATED LIGHT-SOURCE FOR PHAGE FLUOROMETRY AND FLUORESCENCE LIFETIME IMAGING

Phase fluorometry and fluorescence lifetime imaging require a source of exciting light which can be modulated at radiofrequency. This is difficult to achieve with reasonable efficiency using conventional light sources with external modulators such as Pockels cells, while laser sources are limited in wavelength tunability. In this paper a low-cost and versatile high-frequency modulated light source is described which is well suited to frequency-domain fluorescence measurements. The source is a modified deuterium arc lamp which can be driven directly at frequencies up to approximately 130 MHz, and which provides a highly stable source of ultraviolet and visible light. © 1995 American Institute of Physics.