Characteristic Analyses of a Polarization Splitter with a Circular and an Elliptical Cores

Abstract

In this paper, we propose a new polarization splitter constructed from a circular core fiber (fiber1) and an elliptical core fiber (fiber2). The polarization splitters are designed so that the x-polarization and the y-polarization are derived from the fiber2 and the fiber1, respectively. The device length L_m and the bandwidth BW_-15 at R≤-15dB (R: the extinction ratio) are discussed by adjusting mainly the ellipticity e₂ of the core in the fiber2 and the relative index difference Δ₂ of the fiber2. When e₂ and Δ₂ are varied in the range 0.60≤e₂≤0.85 and 0.5%≤Δ₂≤1.0%, respectively, it is found that: (1) L_m takes its minimum value 18.96mm at Δ₂=1.0% and e₂=0.79; (2) BW_-15 takes its maximum value 4.98nm at Δ₂=1.0% and e₂=0.85.