Photonic Crystal Fibers(1) Optical Properties

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1 Photonic Crystal Fibers(1) Optical Properties M.FujitaM.TanakaS.Yamadori A.Suzuki S.Koyanagi T.Yamamoto Summary The cladding of Photonic Crystal Fiber (PCF) is constituted of air holes arranged as periodically as the wavelength of light in the silica glass. The cladding having a structure made up of silica glass and air holes enables characteristics that are quite different from those of conventional fibers. In this paper, we introduce the outline of fabrication and structure of PCF and explain dominant optical properties of PCF compared with those of conventional step index fibers. Key wordsoptical fiber, Photonic crystal fiber, Singlemode fiber, Fiber characterization TIRTotal Internal Reflection PBGPhotonic Band Gap PCF : Photonic Crystal Fiber Russel 1996 PBG PBG PCF PBG1997Honeycomb Lattice PBG

2 Triangular Lattice PBGPCF PBG PCF PCF PCF a b PCF PCFPBG Fig. 1 PCF PCF Fig. 2 c d Examples of photonic crystal fibers aindex guiding PCF bairclad fiber choleassisted fiber dpbf apcfb cdpbf Fig. 1 SEM photograph of PCF PCF HF : Holey Fiber MicroStructured Fiber PCF Fig. 2 PBG PCFPBFPBGF Fig. 2d PCFIndex Guiding PCF PCF Fig. 2a Fig. 2b Ge Fig. 2c Holey Fiber Holeassisted PCF Table 1 TriangularHoneycomb Fig. 3ab Single Defect

3 Table 1 Structure of PCF PCF Triangular) Honeycomb) PCF Stack Draw StackDraw Fig. 4PCF Fig. 3 Crosssectional view of photonic crystal fibers atriangular structure bhoneycomb structure ab Defect PCF Fig. 3a PCF Λ d2a d/λ Λ A i r Filling FractionF Λ/λ Λ 2a 2Λ Fig. 4 Fabrication process of PCF PCF PCF PCF PCF ESMEndlesslySingle Mode xy

4 99 22 PCF PCF PCF ESM ESM b k 2p/l neff=b/k d/l=.6nefffig. 5 l d/l=.6l/l 1.5 d/l d/l.4 ESM V λ V 2.4 PCF Λnoneff neff Fig. 5 Veff Fig. 6 Veff Λ/λ Fig. 6 eff versus Λ/λ eff Λ/λ Fig. 5 Effective cladding index and modal index d/λ.6 Fig. 5 l l d/l Veff Veff PCF 4.1 d/l.4 Fig. 7 PCF d/l=.45 ESMV V V 2.4 a:λnconcl nconcl aλ=155nm bλ=532nm Fig.7 Near field pattern of PCF d/λ.45

5 532nm 155nm Fig. 8 PCF 532nm Table 2 Mode field diameter d/λ.6 PCF SMF MM µmsmf MM n NA PCF neff nco NA Fig. 9 PCF NA Fig. 8 Far field pattern at λ=532nm 532nmd/Λ.45 PCF NA V w Fig. 9 Far field pattern when illuminated with a whitelight source a: V PCF V d/λ=.6 Table 2 1.3µm NA NA OH PCF PCF Fig.1 Fig.11 1/λ 4 Λ 7.3µmd 4.2µm.47dB/km@1.55µm.5dB/km A=1.2 B=.25 A

6 99 22 Fig. 1 Loss spectrum Λ7.3µmd4.2µ Fig. 11 1/λ 4 plot 1/λ 4 B OH PCF PCF Confinement Loss PCF W d/λ Λ=2.3µm Fig.12 d/λ PCF Fig. 12 Confinement loss as a function of wavelength Λ 2.3µm 3 PCF PCF Fig.13 d/λ d/λ Fig. 13 Bending loss properties Λ2.3µm Fig.13 Λ=2.3µm d/λ.35 PCF Table 3 Λ 2.1µmd 1.1µmd/Λ

7 .52 PCF Table 3 Bending loss Λ2.1µmd/Λ.5 db/m mm µm 1.31 SMF.12 DSF.4 DCF PCF Fig.13 dλ d Λ Λ/2 PCF Ge 1.27µm 1.27µm PCF Ge 1.27µm PCF Λ=2.3µm d/λ Fig.14 d/λ d/λ Fig. 14 Group velocity dispersion GVD Λ 2.3µm PCF 1.27µmFig.14d/Λ=.45.8µm PCF1µm (21) PANDAPolarizationmaintaining AND Absorptionreducing PCF (22) Fig.15 PCF

8 99 22 PCF Fig.15 PCF Fig.16 (23) 1.55µm PCF PCF (24) PCF NTT Fig. 15 SEM photograph of polarization maintaining PCF PCF Fig. 16 Modal birefringence PCF PCF E. Yablonovitch, Photonic bandgap structures, J. Opt. Soc. Am. B, 1, 1993, p T. A. Birks, P. J. Roberts, P. St. J. Russell, D. M. Atkin, T. J. Shepherd, Full 2D photonic band gaps in silica/ air structures, Electron. Lett. 31, 1995, p J. C. Knight, T. A. Birks, P. St. J. Russell, D. M. Atkin, Pure silica singlemode fiber with hexagonal photonic crystal cladding, postdeadline paper PD3 at OFC1996. J. Broeng, S. E. Barkou, A. Bjarklev, J. C. Knight, T. A. Birks, P. St. J. Russell, Highly increased photonic band gaps in silica/air structures, Opt. Commun. 156, 1997, p J. C. Knight, J. Broeng, T. A. Birks, P. St. J. Russell, Photonic band gap guidance in opticalfibres, Science, 282, 1998, p T. M. Monro, D. J. Richardson, N. G. R. Broderick, P. J. Bennett, Holey optical fibers: An efficient modal model, J. Lightwave Technol., 17, 1999, p B. J. Eggleton, P. S. Westbrook, R. S. Windeler, S. Spälter, T. A. Strasser, Grating resonances in airsilica microstructured optical fibers, Opt. Lett. 24, 1999, p J. A. West, N. Venkataramam, C. M. Smith, M. T. Gallagher, Photonic Crystal Fibers, ECOC21, Th. A Hasegawa, T., Sasaoka, E., Onishi, M., Nishimura, M., Novel holeassisted lightguide fiber exhibiting large anomalous dispersion and low loss below 1 db/km, OFC21, PD5. J. Broeng, D. Mogilevstev, S. E. Barkou, A. Bjarklev, Photonic crystal fibres : A new class of optical waveguides, Opt. Fib. Tech. 5, 1999, p J. C. Knight, T. A. Birks, P. St. J. Russell, D. M. Atkin, Allsilica singlemode fiber with photonic crystal cladding, Opt. Lett. 21, 1996, p

9 T. A. Birks, J. C. Knight, P. St. J. Russell, Endlessly singlemode photonic crystal fiber, Opt. Lett. 22, 1997, p J. Broeng, S. E. Barkou, A. Bjarklev, T. Søndergaard, E. Knudsen, Review paper : Crystal fibre technology, DOPSNYT 22. T. A. Birks, D. Moglevtsev, J. C. Knight, P. St. J. Russell, J. Broeng, P. J. Roberts, J. A. West, D. C. Allen, J. C. Fajardo, The analogy between photonic crystal fibers and step index fibers, OFC 1999, p D. Marcuse, Loss Analysis of SingleMode Fiber Splice, Bell Sys. Tech. J.56, 1977, p T. P. White, R. C. McPhedran, C. M. de Sterke, L. C. Botten, M. J. Steel, Confinement losses in microstructured optical fibers, Opt. Lett. 26, 21, p T. Sørensen, J. Broeng, A. Bjarklev, E. Knudsen, S. E. Barkou, Macrobending loss properties of photonic crystal fibre, Electron Lett. 37, 21, p A. Bjarklev, T. P. Hansen, K. Hougaard, S. E. Barkou, E. Knudsen, J. Broeng, Microbending in photonic crystal fibres An ultimate loss limit?, ECOC21 We.L.2.4. J. K. Ranka, R. S. Windeler, A. J. Stentz, Visible continuum generation in airsilica microstructure optical fibers with anomalous dispersion at 8nm, Opt. Lett. 25, 2, p Kubota, H., Suzuki, K., Kawanishi, S., Nakazawa, M., Tanaka, M., Fujita, M., Lowloss, 2kmlong photonic crystal fiber with zero GVD in the near IR suitable for picosecond pulse propagation at 8nm band, CLEO21 CPD3. (21) A. Ferrando, ESilverstre, J. J. Miret, and P. Andres, Nearly zero ultraflattened dispersion in photonic crystal fibers, Opt. Lett. 25, 2, p (22)., 2, B1153, 2. (23) Suzuki, K., Kubota, H., Kawanishi, S., Tanaka, M., Fujita, M., Highspeed bidirectional polarization division multiplexed optical transmission in ultra lowloss1.3db/km polarization maintaining photonic crystal fibre, Electron Lett. 37, 21, p (24) T. M. Monro, Holey Optical Fibers: Fundamentals and Applications, OFC22 Tutorial. PCF PCF