Abstract

Recently, the generation of coherent, octave-spanning, and recompressible supercontinuum (SC) light has been demonstrated in optical fibers with all-normal group velocity dispersion (GVD) behavior by femtosecond pumping. In the normal dispersion regime, soliton dynamics are suppressed and the SC generation process is mainly due to self-phase modulation and optical wave breaking. This makes such white light sources suitable for time-resolved applications. The broadest spectra can be obtained when the pump wavelength equals the wavelength of maximum all-normal GVD. Therefore each available pump wavelength requires a specifically designed optical fiber with suitable GVD to unfold its full power. We investigate the possibilities to shift the all-normal maximum dispersion wavelength in microstructured optical fibers from the near infra red (NIR) to the ultra violet (UV). In general, a submicron guiding fiber core surrounded by a holey region is required to overcome the material dispersion of silica. Photonic crystal fibers (PCFs) with a hexagonal array of holes as well as suspended core fibers are simulated for this purpose over a wide field of parameters. The PCFs are varied concerning their air hole diameter and pitch and the suspended core fibers are varied concerning the number of supporting walls and the wall width. We show that these two fiber types complement each other well in their possible wavelength regions for all-normal GVD. While the PCFs are suitable for obtaining a maximum all-normal GVD in the NIR, suspended core fibers are well applicable in the visible wavelength range.

© 2011 OSA

Full Article  |  PDF Article

References

  • View by:
  • |
  • |
  • |

  1. P. S. J. Russell, “Photonic crystal fibers,” Science 299(5605), 358–362 (2003).
    [CrossRef] [PubMed]
  2. J. K. Ranka, R. S. Windeler, and A. J. Stentz, “Visible continuum generation in air-silica microstructure optical fibers with anomalous dispersion at 800 nm,” Opt. Lett. 25(1), 25–27 (2000).
    [CrossRef]
  3. K. Saitoh, M. Koshiba, and N. A. Mortensen, “Nonlinear photonic crystal fibers: pushing the zero-dispersion towards the visible,” N. J. Phys. 8(9), 1–9 (2006).
    [CrossRef]
  4. K. M. Hilligsøe, T. V. Andersen, H. N. Paulsen, C. Nielsen, K. Mølmer, S. Keiding, R. Kristiansen, K. P. Hansen, and J. Larsen, “Supercontinuum generation in a photonic crystal fiber with two zero dispersion wavelengths,” Opt. Express 12(6), 1045–1054 (2004).
    [CrossRef] [PubMed]
  5. A. M. Heidt, A. Hartung, G. W. Bosman, P. Krok, E. G. Rohwer, H. Schwoerer, and H. Bartelt, “Coherent octave spanning near-infrared and visible supercontinuum generation in all-normal dispersion photonic crystal fibers,” Opt. Express 19(4), 3775–3787 (2011).
    [CrossRef] [PubMed]
  6. A. M. Heidt, “Pulse preserving flat-top supercontinuum generation in all-normal dispersion photonic crystal fibers,” J. Opt. Soc. Am. B 27(3), 550–559 (2010).
    [CrossRef]
  7. M. A. Foster, K. D. Moll, and A. L. Gaeta, “Optimal waveguide dimensions for nonlinear interactions,” Opt. Express 12(13), 2880–2887 (2004).
    [CrossRef] [PubMed]

2011 (1)

2010 (1)

2006 (1)

K. Saitoh, M. Koshiba, and N. A. Mortensen, “Nonlinear photonic crystal fibers: pushing the zero-dispersion towards the visible,” N. J. Phys. 8(9), 1–9 (2006).
[CrossRef]

2004 (2)

2003 (1)

P. S. J. Russell, “Photonic crystal fibers,” Science 299(5605), 358–362 (2003).
[CrossRef] [PubMed]

2000 (1)

Andersen, T. V.

Bartelt, H.

Bosman, G. W.

Foster, M. A.

Gaeta, A. L.

Hansen, K. P.

Hartung, A.

Heidt, A. M.

Hilligsøe, K. M.

Keiding, S.

Koshiba, M.

K. Saitoh, M. Koshiba, and N. A. Mortensen, “Nonlinear photonic crystal fibers: pushing the zero-dispersion towards the visible,” N. J. Phys. 8(9), 1–9 (2006).
[CrossRef]

Kristiansen, R.

Krok, P.

Larsen, J.

Moll, K. D.

Mølmer, K.

Mortensen, N. A.

K. Saitoh, M. Koshiba, and N. A. Mortensen, “Nonlinear photonic crystal fibers: pushing the zero-dispersion towards the visible,” N. J. Phys. 8(9), 1–9 (2006).
[CrossRef]

Nielsen, C.

Paulsen, H. N.

Ranka, J. K.

Rohwer, E. G.

Russell, P. S. J.

P. S. J. Russell, “Photonic crystal fibers,” Science 299(5605), 358–362 (2003).
[CrossRef] [PubMed]

Saitoh, K.

K. Saitoh, M. Koshiba, and N. A. Mortensen, “Nonlinear photonic crystal fibers: pushing the zero-dispersion towards the visible,” N. J. Phys. 8(9), 1–9 (2006).
[CrossRef]

Schwoerer, H.

Stentz, A. J.

Windeler, R. S.

Cited By

OSA participates in CrossRef's Cited-By Linking service. Citing articles from OSA journals and other participating publishers are listed here.

Alert me when this article is cited.


Figures (9)

Fig. 1
Fig. 1

Resulting spectrograms for typical SCG in PCFs with a) a single ZDW ([2], Λ = 1.6 µm, d hole = 1.4 µm, 100 fs, 10 kW peak power, 800 nm) and c) SCG in all-normal GVD optical fibers ([5], Λ = 1.44 µm, d hole = 0.56 µm, 50 fs, 8 nJ pulse energy, 1050 nm). b) Illustration of corresponding GVD behavior. Arrows mark recommended pump wavelengths.

Fig. 2
Fig. 2

Scanning electron microscope images of an all-normal dispersion a) SCF and b) PCF. Both fibers were stacked and drawn at the IPHT Jena. The scale bar is a) 1 µm and b) 100 nm.

Fig. 3
Fig. 3

a) GVD of a nanofiber for various fiber diameters and b) MDW properties.

Fig. 4
Fig. 4

Various SCF geometries discussed in the text. The upper row presences ideal polygonal SCFs (left to right: N = 3, 4, 6, 12) with vanishing wall width w. Dark blue represents silica and light blue represents air. In the lower row polygonal SCFs with a wall width of w = 50 nm are illustrated. The incircle core diameter is 700 nm in all cases.

Fig. 5
Fig. 5

a) GVD of a SCF with N = 3 and w = 0. GVD maximum enters NDR at 615 nm wavelength. b) Maximum dispersion for various SCFs with w = 0 as a function of core diameter. With increased number of walls N the SCF MDW approaches the MDW of the nanofiber. The SCF core sizes evaluated in b) are identical to those presented in a).

Fig. 6
Fig. 6

a) Influence of wall width on GVD. The maximum GVD decreases with increasing wall width at nearly constant MDW. b) Interplay of core and wall size. Smallest MDW in the NDR is reached at vanishing wall width. Higher MDW in the NDR is possible when both wall and core size is increased. c) Impact of wall width on GVD increases dramatically with wall number N.

Fig. 7
Fig. 7

Various GVD curves illustrating the richness in designing the dispersion of PCFs by pitch Λ and air filling fraction d hole/Λ. Within the NDR the lower MDW limit approaches the nanofiber value and the upper MDW limit around 1300 nm is set by the disappearance of any GVD maximum for larger Λ.

Fig. 8
Fig. 8

a) Upper limit for an all-normal GVD maximum is set by disappearance of any GVD maximum around Λ = 2500 nm. b) Influence of air filling fraction at constant pitch on GVD.

Fig. 9
Fig. 9

Comparison of GVD for a SCF and PCF with identically shaped core and indexed step. The PCF parameters are Λ = 550 nm and dhole = 500 nm.

Metrics