  A 2-D spatio-temporal analysis of terahertz generation by optical
rectification of tilted-pulse-fronts is presented. Closed form expressions of
terahertz transients and spectra in two spatial dimensions are furnished in the
undepleted limit. Importantly, the analysis incorporates spatio-temporal
distortions of the optical pump pulse such as angular dispersion,
group-velocity dispersion due to angular dispersion, spatial and temporal chirp
as well as beam curvature. The importance of the radius of curvature to the
tilt-angle and group-velocity dispersion due to angular dispersion to terahertz
frequency, conversion efficiency and peak field is revealed.In particular, the
deterioration of terahertz frequency, efficiency and field at large pump
bandwidths and beam sizes is analytically shown.
