  Multi-object or integral field spectrographs are recognized techniques for
achieving simultaneous spectroscopic observations of different or extended sky
objects with a high multiplex factor. In this communication is described a
complementary approach for realizing similar measurements under different
spectral resolutions at the same time. We describe the basic principle of this
new type of spectrometer, that is based on the utilization of an optical pupil
slicer. An optical design inspired from an already studied instrument is then
presented and commented for the sake of illustration. Technical issues about
the pupil slicer and diffractive components are also discussed. We finally
conclude on the potential advantages and drawbacks of the proposed system.
