Based on the principle of electromagnetic force

a method for current measurement is proposed.The axial strain emerges and leads to central wavelength drifted if Bragg under the pull of permanent magnet.The current is measured by demodulating the wavelength shifts.Experiments are carried out by using many circles of solenoid and small current.The DC of 0

3

A is test.The experiment results show that the relation between the wavelength shift and the current has a linearity of 0.9998

and the sensitivity is about 0.97nm/A.