Design of a nanoseconds time-resolved fluorometer

Abstract

The development of an instrument to measure time-domain optical signals, produced by induced fluorescence is presented in this work. The instrument consists of two main subsystems: a) an optical one, which includes continuous and pulsed UV light sources, a Czerny-Turner type monochromator and a high sensitivity photo multiplier tube (PMT), and b) a high-speed digitizer designed with a high performance digital signal processor (DSP), a high bandwidth analog to digital converter (750 MHz), and a computer. A program running on the DSP applies sequential time-equivalent sampling technique, to resolve time-domain fluorescence signals. The processor communicates with the computer via a standard serial port to receive commands and to transmit data. A control program was developed in the graphical language G of LabVIEW¿ 7.1 to register and plot the time-resolved fluorescence pulses. The developed instrument is able to resolve 4 ns rise time pulses with 0.5% error and a resolution of 150 ps.