Birefringence switching of Bragg gratings in fibers with internal electrodes.
A fiber Bragg grating was written in a side-hole fiber with internal metal alloy electrodes. The initial geometrical birefringence of this fiber gives rise to two Bragg resonances separated by 43 pm. Nanosecond risetime current pulses of up to 23 A were applied to the metal electrode, which heated and expanded rapidly. This caused mechanical stress in the fiber on a nanosecond scale, resulting in a negative shift of the Bragg wavelength peak for the fast axis mode, and positive but smaller shift for the slow axis mode. The fast change increased the peak separation to approximately 143 pm, corresponding to an increase in birefringence from 4.0 x 10(-5) to 1.3 x 10(-4). Both peaks subsequently experienced a red-shift due to the relaxation of mechanical stress and the increasing core temperature transferred from the metal in many microseconds. Simulations give accurate description of the experimental results.
JORCEP [Joint Research Centre of Photonics of the Royal Institute of Technology (Sweden) and Zhejiang University], Zhejiang University, Hangzhou 310058, China.
Zhangwei
Z
Yu
O
O
Tarasenko
W
W
Margulis
P-Y
PY
Fonjallaz
D001718:Birefringence; D003198:Computer Simulation; D017076:Computer-Aided Design; D004867:Equipment Design; D019544:Equipment Failure Analysis; D005336:Fiber Optic Technology / Q000295:instrumentation*; D008839:Microelectrodes; D008962:Models, Theoretical; D012031:Refractometry / Q000295:instrumentation*; D012815:Signal Processing, Computer-Assisted / Q000295:instrumentation*