  The Herschel Space Observatory is a corner stone mission of the European
Space Agency (ESA) scientific program. With its spatial resolution, sensitivity
and spectral range (60 to 670 microns) Herschel will provide astronomers with
unique opportunities to decipher many aspects of star formation mecanisms and
galaxy evolution.
  Among the many research institutes involved in the development and
exploitation of this challenging observatory, the Commissariat a l'Energie
Atomique (CEA) designed a novel type of bolometric detectors to equip the
photometer of the PACS instrument on-board the Herschel satellite.
  In this thesis, I present the basics of infrared astronomy and past and
present developments in cryogenic bolometers, emphasising on new concepts
introduced by CEA, that is the collective manufacturing of bolometer arrays,
the high impedance thermometers, the cold multiplexing and the use of a
resonant cavity to optimize absorption of electromagnetic radiation. I follow
with an in-depth explanation of the working principles of CEA bolometer arrays,
a prerequisite to grasp the strategy of the characterisation procedure that we
developed. I then expose and analyse thoroughly the results that we obtained
during the calibration campaign of the PACS photometer. Finally, I express
detector performances in terms of "observational" performances that future PACS
users can comprehend (time constant -> PSF smearing, NEP -> sensitivity, etc.).

Astrophysics