FIB Moiré gratings and their application in the measurement of optical fibers' mechanical properties

Focused ion beam (FIB) milling technique is used to fabricate specimen grating with frequency of 1000 lines/mm on the surface of optical fiber, and in-situ tensile tests are carried out by using a scanning electron microscope (SEM). The SEM scanning Moiré is formed by the superposition of the specimen grating and SEM scanning lines. The displacement field and strain field are obtained by taking advantage of the SEM Moiré method combining with random phase-shifting technique. The tensile properties of the optical fibers are measured according to the stress-strain curve. The experimental results of the SEM Moiré method based on FIB grating demonstrate a good agreement with the parameters obtained from commercial tensile testing machine.