Filter fluorimeters:

Filter fluorimeters frequent employ a low-pressure mercury vapour lamp. This source generates intense lines at certain wavelengths. One of these lines will commonly be appropriate for excitation of a fluorescent sample. Spectrofluorometers, instead, need a continuous radiation source, are frequent equipped along with a 75-450 W high-pressure xenon arc lamp. These generate an intense continuum among about 250 and 600 nm. As the xenon arc lamp produces lot of heat, the lamp assembly required to be cooled thus, these instruments cannot be used for routine work.

For certain applications, it is preferable to use a laser excitation source. A tuneable dye laser, using a pulsed nitrogen laser as the primary source could produce monochromatic radiation among 360 and 650 nm. Because the radiation produced is monochromatic, there is no required for an excitation monochromator. A few fluorescence spectrometers using laser sources are commercially available; most such instruments are intended for highly exact applications such as analysis of uranium within the nuclear industry.