The fluorescence emission after the testing laser iiradiated the sample called laser induced fluorescence(LIF).Due to the laser induced fluorescence detected the exposure light which have different direction and wavelength comparing with laser which have strong directivity and monochromaticity. So it has the high sensitivity compared with other laser spectroscopy.It has been reported to detect 100 atoms per cm3.For most molecules, it can easily test to 106 per cm3.Bylaser frequency modulation, you can choose to stimulate the transition of the initial state and final state, so it can resolve complex molecular spectral bands.
Measure time-resolved fluorescence using pulsed laser as light source, can be used to measure fluorescence lifetime, quantum pulse spectrum, relaxation phenomena… etc.
