Volume 111, Issue 19, 15 November 1999
Index of content:
Relationship between bipolar moments and molecule-frame polarization parameters in Doppler photofragment spectroscopy111(1999); http://dx.doi.org/10.1063/1.480223View Description Hide Description
In terms of the molecular-frame polarization parameters an equation is derived that describes the shape of a photofragment Doppler profile as a function of the three angles Γ, Δ, and Φ that specify the photolysis and probe laser polarizations about the detection axis. This expression is specialized to linearly polarized photolysis and probe laser beams. For the particular value of the angle between the probe laser polarization and the detection axis, this equation can be reduced to the form of well-known laboratory-frame expressions that use the bipolar moment formalism introduced by Dixon. Comparison of these forms shows the equivalence of the two formalisms and gives the relationships between the bipolar moments and the molecule-frame parameters. We show that linear combinations of the bipolar moments completely describe photofragment polarization in the molecular frame and possess distinct quantum mechanical significance. In particular, it is shown that the coherent contribution to the photofragment alignment is proportional to the linear combination
111(1999); http://dx.doi.org/10.1063/1.480222View Description Hide Description
Absorption signals of single terrylene molecules in n-hexadecane and naphthalene crystals were recorded at liquid-helium temperatures. The method is based upon rf Stark effect modulation in the megahertz range. The electric rf field strength was applied by means of interdigitating electrodes with 18 μm spacing. Signal-to-noise ratios better than 10 were obtained with approximately 300 ms integration time. The measured line shapes depend on the relative contributions of the linear and the quadratic Stark shift.