Measurements of fibers' thermal-optic coefficient based on optical fiber Bragg grating sensor

摘要

Optic fibers are applied in the field of high speed photography more and more, for its good properties. At present,various new-style fibers come out ,and these new-style optic fibers' core material are not based on pure quartz traditionally. To know the new-style fibers' properties quantitatively, thermal-optic coefficient is indispensable to get. Therefore this article describes a new way to measure fibers' thermal-optic coefficient based on optical fiber Bragg grating(FBG) sensor. With a temperature referrence grating and a measuremental grating, experimental system is developed,combined with the characteristics of fiber Bragg grating. Experimental setup and measurement principle are discussed. The result of experiment proves that the system can solve the existent cross sensitive problem which caused by temperature and the strain effectively. The fibers' thermal-optic coefficient are measured successfully, within ± 1%.