Surface plasmon polaritons in thin metal films and their role in fiber optic polarizing devices

The polarization-selective evanescent field coupling of an optical wave in a 1.3- μm, fiber to surface, plasmon polaritons supported by a thin aluminium film was investigated theoretically and experimentally. Good agreement was observed between the theoretically predicted conditions for efficient coupling and the experimentally determined conditions for high TM/TE extinction ratio of the optical field. The use of silver and chrome in place of aluminum was investigated experimentally at 1.3 μm, and 0.63- μm devices using aluminium were also studied. The results led to the realization of readily manufacturable, high-extinction-ratio (>50 dB) low-loss (<0.5 dB) fiber optic polarizers and polarizing couplers in standard and highly birefringent fiber.