MIDI (MID-infrared Interferometric instrument)


MIDIMIDI was the mid-infrared (N-band = 8 to 13 μm) instrument of the VLT interferometer. It combines two beams (either from the 8.2-m Unit Telescopes or from the 1.8-m Auxiliary Telescopes) to provide visibility moduli in the (u,v) plane. MIDI features spectroscopic optics to provide visibilities at different wavelengths within the N-band.

MIDI was decommissioned at the end of P94 (March 2015), to allow preparation of the VLTI for the 2nd generation instruments.

Contact Information

  • Questions related to service mode observations and proposal preparation should be addressed to the User Support Department.
  • Questions related to visitor mode observations should be addressed to Paranal Science Operations
  • Please send us your comments, suggestions and report errors and inaccurate statements in the web pages and manuals.

Content of these pages

The following items are available on all the MIDI pages, using the bar on the left.

  • Overview: a short description of the instrument
  • News: list of changes that affected the instrument and/or its operation.
  • Instrument Description: all the important parameters of the instrument.
  • Manuals: links to all the documents related to MIDI during it operational lifespan.
  • Tools: a collection of useful tools and informations for analyzing the MIDI observations.
  • Links: miscellaneous links about interferometry and MIDI.


Publications based on data obtained with the MIDI instrument should quote the following reference paper:

Leinert, Ch, et al., "MIDI - the 10 mum instrument on the VLTI", 2003, Ap&SS 286, 73