Plasmonic Nodeless Hollow-Core Photonic Crystal Fibers for In-Fiber Polarizers

Abstract

A novel plasmonic nodeless hollow-core photonic crystal fiber (NHC-PCF) is proposed based on selective metal incorporation in the cladding tubes. The polarization filtering characteristics of the plasmonic NHC-PCF are investigated in detail. The effects of the fiber structural parameters such as cladding tube thickness, tube diameter, tube gap, and core diameter on the polarization characteristics are fully discussed. The coupling mechanism between core modes and specific surface plasmon polariton (SPP) modes at resonant wavelengths is analyzed, which clarifies the different confinement losses of core modes in two perpendicular directions for both gold-filled and gold-coated NHC-PCFs. In addition, enhanced polarization filtering function can be implemented by double gold incorporation structures, especially, the particular SPP supermode coupling is noticed. The in-fiber NHC-PCF polarizers with the wavelength range of 1310-1550 nm are then designed. Our detailed results will benefit understanding of SPPs in the hollow-core PCFs and accelerate realization of the compact NHC-PCF polarization devices and their wide applications.