ORMOCER Coated Fiber-Optic Bragg Grating Sensors at Cryogenic Temperatures

ORMOCER coated Fiber-Bragg-Gratings (FBGs) were investigated at cryogenic temperatures. Below the Bragg wavelength of uncoated FBG is nearly independent on temperature. ORMOCER coated FBG are temperature dependent over the whole temperature range investigated from 10 to 300 K. For 50-300 K, the ORMOCER coating contributes to an additional linear temperature shift of the Bragg wavelength of 2.4 pm/K. Below 40 K the temperature dependence decreases to 1.0 pm/K. ORMOCER coated FBGs can be used as sensor at cryogenic temperatures.