Radiation-induced attenuation of hollow-core photonic bandgap fiber for space applications

Radiation-Induced Attenuation (RIA) is a crucial parameter for the applications of fiber optic gyroscopes in space environments. Under the irradiation of a 60Co source with a radiation rate of 10 rad/s and a total radiation dose of 138 krad, we make real-time measurements of RIA and evaluate the recovery process of homemade 19-cell HC-PBGF and commercial PPMF. Experimental results demonstrate that there is only a 0.45 dB/km loss increment for the RIA of homemade HC-PBGF at the wavelength of 1550 nm, which is only about 1/27 of that of the PPMF. After the radiation source is turned off, the loss of HC-PBGF returns to the initial level before radiation in the tenth hour, but the RIA of PPMF has only a 20% recovery on the seventh day. We first theoretically investigate the kinetics and phenomenological equation of RIA in the Hollow-Core Photonic Band-Gap Fiber (HCPBGF) and commercial Panda Polarization Maintaining Fiber (PPMF) in the gamma-rays environment. Theoretical results proved that the initial defect concentration and RIA increase rate of HC-PBGF are only 1/3 and 1/6 of that of the PPMF. This proves that HC-PBGF can significantly reduce the RIA and exhibits a strong capacity of irradiation resistance, which is of great significance to promote fiber optic gyroscopes for space applications.