  Spectral differential imaging is an increasingly used technique for
ground-based direct imaging searches for brown dwarf and planetary mass
companions to stars. The technique takes advantage of absorption features that
exist in these cool objects, but not in stars, and is normally implemented
through simultaneous narrow-band imagers in 2 to 4 adjacent channels. However,
by instead using an integral field unit, different spectral features could be
used depending on the actual spectrum, potentially leading to greater
flexibility and stronger detection limits. In this paper, we present the
results of a test of spectral differential imaging using the SINFONI integral
field unit at the VLT to study the nearby active star L449-1. No convincing
companion candidates are found. We find that the method provides a 3 sigma
contrast limit of 7.5 mag at 0.35", which is about 1.5 mag lower than for
NACO-SDI at the same telescope, using the same integration time. We discuss the
reasons for this, and the implications. In addition, we use the SINFONI data to
constrain the spectral type in the NIR for L 449-1, and find a result between
M3.0 and M4.0, in close agreement with a previous classification in the visual
range.
