The concept of "Virtual Image Slicer" was developed and implemented at the Very Large Telescope (VLT). The Virtual Image Slicer consists in elongating the stars in a given direction by the use of the Active Optics of the telescope. Alignment of the major axis of the elongated star along the entrance slit of the spectrograph allows to increase the total signal collected in a single (polarimetric) spectrum by a factor of up to 100 or more relative to a perfectly shaped image for bright sources.