Enhanced fluorescence emission using a programmable, reconfigurable LED-array based light source

Abstract

An array of up to 5 LEDs is presented to optimize the excitation signal that is transferred into a fluorescence analysis system. The array is varied by both type and drive current in order to broadly and narrowly tune the aggregate spectrum generated by the LED array to more closely match the desired excitation spectrum. Optimization results are shown for (a) a theoretical desired spectrum that clearly shows the increased flexibility of the LED array; (b) an experiment with AM1 bacteria demonstrating comparable emission output between a conventional Xenon lamp and an over driven LED array; and (c) an experiment with Rhodamine G that shows over a two-fold improvement in signal to noise ratio (or emission) obtainable using an optimized array over a non-optimized array. The flexibility of the LED array offers up to 3.2 million possibilities for aggregate spectra; without overdrive conditions, the 5-element array can only be configured into a maximum of 1020 different aggregate spectra.

Color Control System for RGB LED Light Sources Using Junction Temperature Measurement

“…Red-green-blue (RGB) LEDs having capability of generating instantly different colors can find many applications in such areas as biomedical apparatus [2], detector system [3], LCD back lighting [4], general decorative illuminations, etc. LEDs are direct band-gap semiconductor p-n junction diodes.…”

High-Power, Computer-Controlled, Light-Emitting Diode–Based Light Sources for Fluorescence Imaging and Image-Guided Surgery

“…In preliminary tests, this increased transmission at all incidence angles to ≥98% (but also increased cost by over 20-fold). And fourth, spectral matching and homogeneity of the radiance could be improved by employing more sophisticated LED arrays [12] and/or control software [13]. Nevertheless, our results should lay the foundation for improved LED-based light sources for optical imaging.…”