Table 1.
TECHNIQUES | JABLONSKI DIAGRAM | NUMBER OF PHOTONS | CONTRAST MECHANICS | INFORMATION |
---|---|---|---|---|
TPEF | 2 | Electronics levels of the molecules | Autofluorescence of some biological substances (NADH, FAD, etc.) | |
SHG | 2 | Nonlinear properties of the medium | Non centrosymmetric molecules with spatial organization (Collagen, Elastin, etc.) | |
THG | 3 | Nonlinear properties of the medium | Interfaces, optical inhomogeneities, (Cell edges, lipids) | |
CARS | 3 | Vibrational levels of the molecules | Chemical information (lipids, DNA) |
Abbreviations: TPEF, two-photon excited fluorescence; SHG, second harmonic generation; THG, third harmonic generation; CARS, coherent anti-Stokes Raman scattering; W, frequency; Ω, vibrational level; NADH, Nicotinamide adenine dinucleotide reduced; FAD, Flavin adenine dinucleotide.