Free Induction decay trace

Fig. 7.24 (a) Optical nutation in CH3p observed with CO2 laser excitation at A = 9.7 pm. The Rabi oscillations appear because the Stark pulse lower trace) is longer than in Fig. 7.23. (b) Optical free-induction decay in I2 vapor following resonant excitation with a cw dye laser at = 589.6 nm. At the time = 0 the laser is frequency-shifted with the arrangement depicted in Fig. 7.22 by Au = 54 MHz out of resonance with the I2 transition. The slowly varying envelope is caused by a superposition with the optical nutation of molecules in the velocity group Vz = o) — (oo)/k, which are now in resonance with the laser frequency oj. Note the difference in time scales of (a) and (b) [705]... 

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