System having a configurable pico-second pulsed LED driver circuit and photomultiplier tube biasing and gating circuits for real-time, time-resolved transient recording of fluorescence

A high-intensity, adjustable pulse width, light-emitting diode (LED) pulsing driver circuit (300), capable of driving an LED (304) with a pulse width range from about 1 ns to 560 ns full width half maximum (FWHM), high-intensity (maximum driving power of 0.5W) pulses, said driver circuit (300) comprising:

• a. a signal shaping circuit (302) configured to generate a positive rectangular wave pulse signal upon receiving an edge trigger, wherein timing of a rising edge and a falling edge of the positive rectangular wave pulse signal are controlled by adjustable delay elements;
• and
• b. a buffer circuit (303), operatively connected to the signal shaping circuit (302), wherein the buffer circuit (303) is configured to convert the positive rectangular wave pulse signal of the signal shaping circuit (302) to a differential pulse, wherein the differential pulse sweeps the LED (304) from a reverse biased to a forward biased voltage followed by a reverse biased voltage;
• wherein when the edge trigger is received by the signal shaping circuit (302), the signal shaping circuit (302) generates the positive rectangular wave pulse signal, wherein the positive rectangular wave pulse signal is sent to the buffer circuit (303), wherein the buffer circuit (303) transforms the positive rectangular wave pulse signal to the differential pulse, wherein the buffer circuit (303) applies the differential pulse signal to the LED (304), wherein the LED (304) is first turned on by being forward biased, followed by being turned off by being reverse biased.