New polarizing optical fibers

Abstract

This paper reviews recent progress and experiment and modeled results on dual air hole-assisted polarizing fibers which can act as either Single Polarization (SP) fiber or Polarization Maintaining (PM) fiber. Dual air hole-assisted fiber design provides both SP and PM characteristics for the same fiber at different wavelength range. SP operating windows centered at wavelength from 980 nm to 1550 nm with bandwidth ranging from 24 nm to 63 nm are demonstrated. Various properties of the fibers are studied. We explored bend and length dependence of SP window which enables fining tuning in actual device application. We also investigated SP and PM characteristics over wide range of temperature, such as fundamental cutoff wavelength, extinction ratio and birefringence. It was found that hole-assisted polarizing fiber provides less temperature sensitivity compared to stress member-assisted polarizing fiber. Lastly, Ytterbium (Yb) doped SP fiber, which combines gain medium and polarizer into single element was realized. Significant benefits can be achieved by using Yb-doped SP fiber in application such as fiber laser or amplifier, which requires linearly polarized output.