Device for optical measurement of cryogenic temperatures.

摘要

The optical method includes analysis of the decline in the luminescence of a doped crystal. The arrangement includes a light source (1) exciting the crystal, and an optical fibre (50,51,52,53) for carrying the light from the source to the crystal, and re-transmitting this from the crystal to a detector. Suitable materials for the doped crystal include SrF2:Yb2+ or CaF2:Yb2+, being doped with divalent ytterbium. The fibres may be encased by a metallic capillary.