Lasers have always been perhaps the most precise type out of excitation light source. They emit a narrow bandwidth of light, meaning they can excite specific fluorophores very accurately. However, they can get expensive and need specialized knowledge to utilize properly.There is several kinds of excitation light sources, plus lasers, light-emitting diodes (LEDs), and also arc lamps. Each has its own advantages plus drawbacks, depending upon the precise application plus the type of sample being studied.