Comment on "Temporally resolved electro-optic effect".

We comment on the recent Letter by S. P. Jamison et al. [Opt. Lett.31, 1753 (2006)] where the analysis of a chirped probe pulse that is electro-optically modulated by a terahertz pulse reportedly results in a new expression for the electric field. While in principle the derived expressions for the total field after the crystal are correct, in their treatment the authors implicitly assumed that the derived total field is identical to the measured field, without regard to the residual birefringence of a typical electro-optic crystal or a crossed analyzer. Based on this analysis neglecting birefringence, they report that earlier expressions of the temporal field are incorrect. Here we show, on the contrary, that for chirped single-shot terahertz measurement schemes that include residual birefringence, the temporally resolved electro-optic effect is described correctly by the commonly used expression in the literature. We verify this result with our experimental data.