We present precise expressions of the spatial and angular Goos-Haenchen and
Imbert-Fedorov shifts experienced by a longitudinally and transversally limited
beam of light (wave packet) upon reflection from a dielectric interface, as
opposed to the well-known case of a monochromatic beam which is bounded in
transverse directions but infinitely extended along the direction of
propagation. This is done under the assumption that the detector time is longer
than the temporal length of the wave packet (wave packet regime). Our results
will be applied to the case of a Gaussian wave packet and show that, at the
leading order in the Taylor expansion of reflected-field amplitudes, the
results are the same of the monochromatic case
