Pulsed LED light source for fluorescence spectroscopy applications

Abstract

In this study we compared the fluorescence emission of algal, river water/wastewater, and oil samples using a pulsed LED light source and an Ocean Optics Xenon Arc Lamp source. Light-emitting diodes (LED) had become an important light source in the field of fluorescence spectroscopy and Lamp type LEDs are cheap and can provide a narrow source of wavelength as compared to the continuous Xenon Arc lamp source. However, it is sensitive to static electricity and electrical power. If the LED is operated in pulsed mode, it can provide stable high intensity at a longer time. For the experiment, the operating modes of the three pulsed LED are 20mW, 50µs at 500Hz. For the river water samples, the fluorescence emission showed significant results at 500-nm. At 685-nm emission wavelength of the algal samples, the pulsed LED signal showed a positive correlation with the Xenon lamp. However, peak shifting was observed for the oil samples due to low excitation intensity observed.