Radiation-Tolerant Superfluorescent Fiber Sources for High-Performance Fiber-Optic Gyroscopes Working Under Gamma Irradiation Higher Than 200 krad

Two effective methods, bidirectional-pump doublepass (BPDP) configuration and green light photo-annealing (GLPA) technique, are proposed to obtain radiation-tolerant superfluorescent fiber sources (SFSs) for high performance interferometric fiber-optic gyroscopes ('FOGs). The results show that the SFS prepared by each method could maintain the same meanwavelength under γ-irradiation higher than 200 krad, and still have a broad linewidth larger than 34 nm. The lowest output power loss was experimentally demonstrated to be as low as 0.6 dB for 40-mW output power. Such radiation-tolerant SFSs have better performance than those reported previously, and can be used for an 'FOG in both the low-Earth orbit (LEO) and the geostationary Earth orbit (GEO) applications.