High Temperature Long Period Grating Thermo-Mechanically Written

An optical fiber transducer able to work in high temperature environments is experimentally demonstrated in the laboratory. It is based on a permanent long period grating (LPG) written using a new technique based on a thermo-mechanical approach. Device precision was experimentally checked by means of repetitive thermal cycles between 25 and 950 oC. In addition device stability was assured by maintaining the temperature in steady state at 800 oC during 23 hours.