Study on transverse-load characteristics and polarization dependence of novel long period fiber gratings

It is demonstrated that the transverse-load characteristic of the resonant wavelength for LPFGs induced by high-frequency CO2 laser pulses depends strongly on the load-direction, whereas the transverse-load characteristics of the loss peak amplitude is independent on the load-direction. The polarization dependence of the resonant wavelength for the LPFGs is deeply affected by the transverse-load, and the affection depends on load direction, whereas, the polarization dependence of the loss peak amplitude is little affected by the transverse-load. The transverse-load resulted in the optical-axis of the LPFG rotating. The unique transverse-load characteristics of the novel LPFG are analyzed using the theories about the optical-axis rotation, resulting from the load-induced birefringence, of the LPFG.