Development of instrument-on-chip detector arrays for far IR astronomy

Abstract

International audienceOne of the main goals of the BBOP instrument onboard the canceled SPICA project (SPace Infrared telescope for Cosmology and Astrophysics) was to retrieve, with an unprecedented sensitivity, the evidence of structuring magnetic field in different astrophysical objects, by means of the emitted/absorbed polarized light observation. For this purpose, polarization in pixel detectors should simplify and improve reliability of the instruments, especially in space applications because of compactness, lightweight and absence of rotating mechanism for Stokes parameters determination. The recent results from the array prototype funded by ESA already fulfills most of the expected performances. In addition, two solutions of optical spectroscopy-on-chip are currently under study in our group to benefit of the same imaging advantages with a spectral resolution close to 300. All these developments are based on the high resistivity bolometer principle demonstrated, in space, on the ESA Herschel Observatory, but completely redesigned. The sensitivity improvement is mainly a consequence of the operating temperature of the detectors (50 mK) and of the fully differential readout circuit