What about Lifetimes? ·Absorption: S1-So very fast 10-15-10-13 s ·Relaxation: Resonant emission S1>So fast 10-9-10-5 s(fluorescence) common in atoms strong absorber=shorter lifetime Non-resonant emission S1->So fast 10-9-10-5 s (fluorescence) common in molecules v.fast vibrational relaxation red shifted emission(Stokes shift) 200250300 Wavelength,nm Fig.15-2 CEM 333 page 5.4What about Lifetimes? • Absorption: S1¬S0 very fast 10-15-10-13 s • Relaxation: Resonant emission S1®S0 fast 10-9-10-5 s (fluorescence) common in atoms strong absorber Þ shorter lifetime Non-resonant emission S1®S0 fast 10-9-10-5 s (fluorescence) common in molecules v. fast vibrational relaxation red shifted emission (Stokes shift) Fig. 15-2 CEM 333 page 5.4