Photonics Research, 2020, 8 (8): 08001278, Published Online: Jul. 14, 2020
Geometric-phase-induced arbitrary polarization and orbital angular momentum generation in helically twisted birefringent photonic crystal fiber Download: 685次
Figures & Tables
Fig. 1. Schematic of (left) three-dimensional structure and (right) cross section of TB-PCF. The number of rings in the three-dimensional sketch is reduced for clarity. The simulation is carried out for the cross section shown in the right panel. The dashed lines are a square with the side length of 2 Λ . The inside area is used to calculate the Poynting vector in the core.
Fig. 2. (Top left) n eff and B and (top right) L pol and α pol as functions of d side , and (bottom) n eff as a function of the twisting rate.
Fig. 3. Optical power in the core of TB-PCFs as a function of propagation distance for different values of d side . Input modes are (left) LCP and (right) RCP modes. α = 0.006 rad / μm .
Fig. 4. (Left) Stokes parameters of TB-PCF for d side = 2.0 μm and α = 0.006 rad / μm and (right) S 3 of TB-PCF for different values of d side calculated by BPM.
Fig. 5. (Left) Stokes parameters of TB-PCF for d side = 2.0 μm and α = 0.006 rad / μm and (right) S 3 of TB-PCF for different values of d side calculated by the analytical method.
Fig. 7. S 3 as a function of propagation distance for α = 0.006 rad / μm and different values of d side . E y mode is launched.
Fig. 8. (Left) Optical power in the core of TB-PCFs and (right) S 3 as a function of propagation distance for different values of α . d side = 2.5 μm .
Fig. 9. (Left) Transmission spectra of TB-PCFs for α = 0.006 rad / μm and different values of d side . E x mode is launched, and the fiber length is 30,000 μm. (Center) S 3 as a function of propagation distance for different wavelength and (right) enlarged view of the center panel.
Fig. 10. Stokes parameters of periodically inverted TB-PCF calculated by (left) the analytical method and (right) BPM. d side = 2.0 μm and α = 0.0024 rad / μm . Dashed vertical lines show the distance of integer multiples of Λ twist / 4 .
Fig. 11. Poincaré sphere plots of the polarization state in TB-PCF with d side = 2.0 μm . (Left) α = 0.0024 rad / μm with constant twisting, (center) α = 0.0024 rad / μm with periodically inverted twisting, and (right) α = 0.006 rad / μm with periodically inverted twisting.
Fig. 12. Stokes parameters of periodically inverted TB-PCF calculated by BPM. d side = 1.25 μm and α = 0.000314 rad / μm . Dashed vertical lines show the distance of integer multiples of Λ twist / 4 .
Fig. 14. Overlap powers (blue solid lines) and total Poynting vectors (black dashed lines) as functions of propagation distance for (left) LP 11 b x and (right) LP 21 b x mode input. The inset shows mixed FFIP at the distance marked by red circles.
Fig. 15. Overlap powers (green and blue) and total Poynting vectors (black) as functions of periodically inverted multimode TB-PCF for (top) LP 11 b x and (bottom) LP 21 b x mode input. The right panels show NFP and mixed FFIP at the distances marked by red circles.
Takeshi Fujisawa, Kunimasa Saitoh. Geometric-phase-induced arbitrary polarization and orbital angular momentum generation in helically twisted birefringent photonic crystal fiber[J]. Photonics Research, 2020, 8(8): 08001278.