Research Groups

Planetary Imaging Group (PIG)

POLICES - POLarimeter for ICE Samples

The POLICES facility is a spectro-gonio-polarimeter to measure the polarisation of a light reflected by an icy analogue. An unpolarised light is sent to a sample made of pure water ice or mixed with salt relevant for the study of the icy moons. The polarisation acquired after reflexion is analysed to be converted in Stoke’s parameter, describing quantitatively the polarisation of the sample.

The instrument consist in an aluminium box (60x60x60cm), allowing measurement with low relative humidity and preventing the formation of frost at the surface of the sample. The incidence angle is fixed at 0°, corresponding to the fixed position of the detector. The light source, composed of 3 different LEDs (530, 625, 810nm) linked to a collimator, is placed on a rotative arm allowing measurement at emission angle between -60° to +60°.

Picture of the box of POLICES. The detector is on the optical module on the top of the box. Few holes on the panels allow putting sensors inside the box and monitor, for example, the relative humidity or temperature of a sample. A camera inside the box enable also to follow the evolution of the sample inside the box.