Polarization selective spectroscopy experiments: methodology and pitfalls

We analyze the effectiveness of various practical implementations of time-dependent pump-probe and transient grating polarization-selective experiments. A variety of optical arrangements are analyzed in the Jones matrix calculus framework. The optical arrangements that permit the correct determination of the time-dependent orientational and excited-state population dynamics are delineated. It is shown that magic angle transient I-rating experiments yield pure population dynamics under certain conditions only. The effectiveness of spectrally resolved magic angle pump-probe and transient grating experiments that use a monochromator are shown to be dependent on the position of an analyzing polarizer along the experimental beam path relative to various other optical elements. The spectrally resolved experiments will measure pure population dynamics only if a polarizer is placed immediately after the sample. The effectiveness of experiments measuring orientational dynamics by separately measuring the probe signal with its polarization parallel and perpendicular to the pump polarization is not constrained by the conditions imposed on the magic angle experiments. (C) 2005 Optical Society of America.