  It is shown that exterior complex scaling provides for complete absorption of
outgoing flux in numerical solutions of the time-dependent Schr\"odinger
equation with strong infrared fields. This is demonstrated by computing high
harmonic spectra and wave-function overlaps with the exact solution for a
one-dimensional model system and by three-dimensional calculations for the H
atom and a Ne atom model. We lay out the key ingredients for correct
implementation and identify criteria for efficient discretization.
