Lead coating to improve Fiber Bragg Grating sensitivity at cryogenic temperatures

Fibre Bragg Grating (FBG) sensors, can be used for temperature monitoring but the low thermal expansion coefficient of silica limits its sensitivity in cryogenic environment. However it will be shown that the use of a lead coating, electrodeposited on an aluminium pre-coated sensor, will enhance FBG sensing properties down to 5 K. Slight variations on the optical response of the coated FBG sensor are interpreted with the micrographic observation of the deposit