Abstract

We report the use of a sub-wavelength optical wire (SOW) with a specifically designed transition region as an efficient tool to filter higher-order modes in multimode waveguides. Higher-order modes are effectively suppressed by controlling the transition taper profile and the diameter of the sub-wavelength optical wire. As a practical example, single-mode operation of a standard telecom optical fiber over a broad spectral window (400~1700 nm) was demonstrated with a 1µm SOW. The ability to obtain robust and stable single-mode operation over a very broad range of wavelengths offers new possibilities for mode control within fiber devices and is relevant to a range of application sectors including high performance fiber lasers, sensors, photolithography, and optical coherence tomography systems.

© 2008 Optical Society of America

Full Article  |  PDF Article

References

  • View by:
  • |
  • |
  • |

  1. K. Okamoto, Fundamentals of Optical Waveguides (Elsevier Academic, London, 2006).
  2. J. Nilson, W. A. Clarkson, R. Selvas, J. K. Sahu, P. W. Turner, S. -U. Alam, and A. B. Grudinin, "High-power wavelength-tunable cladding-pumped rare-earth-doped silica fiber lasers," Opt. Fiber Technol. 10, 5-30 (2004).
    [CrossRef]
  3. O. S. Wolfbeis, "Fiber-optic chemical sensors and biosensors," Anal. Chem. 74, 2663-2678 (2002).
    [CrossRef] [PubMed]
  4. B. A. Flusberg, E. D. Cocker, W. Piyawattanametha, J. C. Jung, E. L. M. Cheung, and M. J. Schnitzer, "Fiber-optic fluorescence imaging," Nat. Methods 2, 941-950 (2005).
    [CrossRef] [PubMed]
  5. T. A. Birks, J. C. Knight, and P. St. J. Russell, "Endlessly single-mode photonic crystal fiber," Opt. Lett. 22, 961-963 (1997).
    [CrossRef] [PubMed]
  6. P. St. J. Russell, "Photonic crystal fibers," Science 299, 358-362 (2003).
    [CrossRef] [PubMed]
  7. L. Tong, R. R. Gattass, J. B. Ashcom, S. He, J. Lou, M. Shen, I. Maxwell, and E. Mazur, "Subwavelength-diameter silica wires for low-loss optical wave guiding," Nature 426, 816-819 (2003).
    [CrossRef] [PubMed]
  8. G. Brambilla, V. Finazzi, and D. J. Richardson, "Ultra-low-loss optical fiber nanotapers," Opt. Express 12, 2258-2263 (2004), http://www.opticsinfobase.org/abstract.cfm?URI=oe-12-10-2258.
    [CrossRef] [PubMed]
  9. S. Moon and D. Y. Kim, "Effective single-mode transmission at wavelengths shorter than the cutoff wavelength of an optical fiber," IEEE Photon. Technol. Lett. 17, 2604-2606 (2005).
    [CrossRef]
  10. D. Donlagic, "In-line higher order mode filters based on long highly uniform fiber tapers," J. Lightwave Technol. 24, 3532-3539 (2006).
    [CrossRef]
  11. M. Sumetsky, Y. Dulashko, and A. Hale, "Fabrication and study of bent and coiled free silica nanowires: Self-coupling microloop optical interferometer," Opt. Express 12, 3521-3531 (2004), http://www.opticsinfobase.org/abstract.cfm?URI=oe-12-15-3521.
    [CrossRef] [PubMed]
  12. D. -I. Yeom, E. C. Mägi, M. R. E. Lamont, M. A. F. Roelens, L. Fu, and B. J. Eggleton, "Low-threshold supercontinuum generation in highly nonlinear chalcogenide nanowires," Opt. Lett. 33, 660-662 (2008), http://www.opticsinfobase.org/abstract.cfm?URI=ol-33-7-660.
    [CrossRef] [PubMed]
  13. F. Xu, P. Horak, and G. Brambilla, "Optical microfiber coil resonator refractometric sensor," Opt. Express. 15, 7888-7893 (2007), http://www.opticsinfobase.org/abstract.cfm?URI=oe-15-12-7888.
    [CrossRef] [PubMed]
  14. V. I. Balykin, K. Hakuta, F. Le Kien, J. Q. Liang, and M. Morinaga, "Atom trapping and guiding with a subwavelength-diameter optical fiber," Phys. Rev. A 70, 011401 (2004).
  15. L. Tong, J. Lou, and E. Mazur, "Single-mode guiding properties of subwavelength-diameter silica and silicon wire waveguides," Opt. Express 12, 1025-1035 (2004).
    [CrossRef] [PubMed]
  16. M. Sumetsky, Y. Dulashko, P. Domachuk, and B. J. Eggleton, "Thinnest optical waveguide: experimental test," Opt. Lett. 32, 754-756 (2007).
    [CrossRef] [PubMed]
  17. F. Bilodeau, K. O. Hill, S. Faucher, and D. C. Johnson, "Low-loss highly overcoupled fused couplers: Fabrication and sensitivity to external pressure," J. Lightwave Technol. 6, 1476- 1482 (1988).
    [CrossRef]
  18. T. A. Birks and Y. W. Li, "The shape of fiber tapers," J. Lightwave Technol. 10, 432-438 (1992).
    [CrossRef]
  19. J. D. Love, W. M. Henry, W. J. Stewart, R. J. Black, S. Lacroix, and F. Gonthier, "Tapered single-mode fibres and devices - Part 1: Adiabaticity criteria," IEE Proceedings-J 138, 343-354 (1991).
  20. R. J. Black, S. Lacroix, F. Gonthier, and J. D. Love, "Tapered single-mode fibres and devices - Part 2: Experimental and theoretical quantification," IEE Proceedings-J 138, 355-364 (1991).

2008 (1)

2007 (2)

2006 (1)

2005 (2)

S. Moon and D. Y. Kim, "Effective single-mode transmission at wavelengths shorter than the cutoff wavelength of an optical fiber," IEEE Photon. Technol. Lett. 17, 2604-2606 (2005).
[CrossRef]

B. A. Flusberg, E. D. Cocker, W. Piyawattanametha, J. C. Jung, E. L. M. Cheung, and M. J. Schnitzer, "Fiber-optic fluorescence imaging," Nat. Methods 2, 941-950 (2005).
[CrossRef] [PubMed]

2004 (5)

2003 (2)

P. St. J. Russell, "Photonic crystal fibers," Science 299, 358-362 (2003).
[CrossRef] [PubMed]

L. Tong, R. R. Gattass, J. B. Ashcom, S. He, J. Lou, M. Shen, I. Maxwell, and E. Mazur, "Subwavelength-diameter silica wires for low-loss optical wave guiding," Nature 426, 816-819 (2003).
[CrossRef] [PubMed]

2002 (1)

O. S. Wolfbeis, "Fiber-optic chemical sensors and biosensors," Anal. Chem. 74, 2663-2678 (2002).
[CrossRef] [PubMed]

1997 (1)

1992 (1)

T. A. Birks and Y. W. Li, "The shape of fiber tapers," J. Lightwave Technol. 10, 432-438 (1992).
[CrossRef]

1991 (2)

J. D. Love, W. M. Henry, W. J. Stewart, R. J. Black, S. Lacroix, and F. Gonthier, "Tapered single-mode fibres and devices - Part 1: Adiabaticity criteria," IEE Proceedings-J 138, 343-354 (1991).

R. J. Black, S. Lacroix, F. Gonthier, and J. D. Love, "Tapered single-mode fibres and devices - Part 2: Experimental and theoretical quantification," IEE Proceedings-J 138, 355-364 (1991).

1988 (1)

F. Bilodeau, K. O. Hill, S. Faucher, and D. C. Johnson, "Low-loss highly overcoupled fused couplers: Fabrication and sensitivity to external pressure," J. Lightwave Technol. 6, 1476- 1482 (1988).
[CrossRef]

Alam, S. -U.

J. Nilson, W. A. Clarkson, R. Selvas, J. K. Sahu, P. W. Turner, S. -U. Alam, and A. B. Grudinin, "High-power wavelength-tunable cladding-pumped rare-earth-doped silica fiber lasers," Opt. Fiber Technol. 10, 5-30 (2004).
[CrossRef]

Ashcom, J. B.

L. Tong, R. R. Gattass, J. B. Ashcom, S. He, J. Lou, M. Shen, I. Maxwell, and E. Mazur, "Subwavelength-diameter silica wires for low-loss optical wave guiding," Nature 426, 816-819 (2003).
[CrossRef] [PubMed]

Balykin, V. I.

V. I. Balykin, K. Hakuta, F. Le Kien, J. Q. Liang, and M. Morinaga, "Atom trapping and guiding with a subwavelength-diameter optical fiber," Phys. Rev. A 70, 011401 (2004).

Bilodeau, F.

F. Bilodeau, K. O. Hill, S. Faucher, and D. C. Johnson, "Low-loss highly overcoupled fused couplers: Fabrication and sensitivity to external pressure," J. Lightwave Technol. 6, 1476- 1482 (1988).
[CrossRef]

Birks, T. A.

Black, R. J.

J. D. Love, W. M. Henry, W. J. Stewart, R. J. Black, S. Lacroix, and F. Gonthier, "Tapered single-mode fibres and devices - Part 1: Adiabaticity criteria," IEE Proceedings-J 138, 343-354 (1991).

R. J. Black, S. Lacroix, F. Gonthier, and J. D. Love, "Tapered single-mode fibres and devices - Part 2: Experimental and theoretical quantification," IEE Proceedings-J 138, 355-364 (1991).

Brambilla, G.

Cheung, E. L. M.

B. A. Flusberg, E. D. Cocker, W. Piyawattanametha, J. C. Jung, E. L. M. Cheung, and M. J. Schnitzer, "Fiber-optic fluorescence imaging," Nat. Methods 2, 941-950 (2005).
[CrossRef] [PubMed]

Clarkson, W. A.

J. Nilson, W. A. Clarkson, R. Selvas, J. K. Sahu, P. W. Turner, S. -U. Alam, and A. B. Grudinin, "High-power wavelength-tunable cladding-pumped rare-earth-doped silica fiber lasers," Opt. Fiber Technol. 10, 5-30 (2004).
[CrossRef]

Cocker, E. D.

B. A. Flusberg, E. D. Cocker, W. Piyawattanametha, J. C. Jung, E. L. M. Cheung, and M. J. Schnitzer, "Fiber-optic fluorescence imaging," Nat. Methods 2, 941-950 (2005).
[CrossRef] [PubMed]

Domachuk, P.

Donlagic, D.

Dulashko, Y.

Eggleton, B. J.

Faucher, S.

F. Bilodeau, K. O. Hill, S. Faucher, and D. C. Johnson, "Low-loss highly overcoupled fused couplers: Fabrication and sensitivity to external pressure," J. Lightwave Technol. 6, 1476- 1482 (1988).
[CrossRef]

Finazzi, V.

Flusberg, B. A.

B. A. Flusberg, E. D. Cocker, W. Piyawattanametha, J. C. Jung, E. L. M. Cheung, and M. J. Schnitzer, "Fiber-optic fluorescence imaging," Nat. Methods 2, 941-950 (2005).
[CrossRef] [PubMed]

Fu, L.

Gattass, R. R.

L. Tong, R. R. Gattass, J. B. Ashcom, S. He, J. Lou, M. Shen, I. Maxwell, and E. Mazur, "Subwavelength-diameter silica wires for low-loss optical wave guiding," Nature 426, 816-819 (2003).
[CrossRef] [PubMed]

Gonthier, F.

R. J. Black, S. Lacroix, F. Gonthier, and J. D. Love, "Tapered single-mode fibres and devices - Part 2: Experimental and theoretical quantification," IEE Proceedings-J 138, 355-364 (1991).

J. D. Love, W. M. Henry, W. J. Stewart, R. J. Black, S. Lacroix, and F. Gonthier, "Tapered single-mode fibres and devices - Part 1: Adiabaticity criteria," IEE Proceedings-J 138, 343-354 (1991).

Grudinin, A. B.

J. Nilson, W. A. Clarkson, R. Selvas, J. K. Sahu, P. W. Turner, S. -U. Alam, and A. B. Grudinin, "High-power wavelength-tunable cladding-pumped rare-earth-doped silica fiber lasers," Opt. Fiber Technol. 10, 5-30 (2004).
[CrossRef]

Hakuta, K.

V. I. Balykin, K. Hakuta, F. Le Kien, J. Q. Liang, and M. Morinaga, "Atom trapping and guiding with a subwavelength-diameter optical fiber," Phys. Rev. A 70, 011401 (2004).

Hale, A.

He, S.

L. Tong, R. R. Gattass, J. B. Ashcom, S. He, J. Lou, M. Shen, I. Maxwell, and E. Mazur, "Subwavelength-diameter silica wires for low-loss optical wave guiding," Nature 426, 816-819 (2003).
[CrossRef] [PubMed]

Henry, W. M.

J. D. Love, W. M. Henry, W. J. Stewart, R. J. Black, S. Lacroix, and F. Gonthier, "Tapered single-mode fibres and devices - Part 1: Adiabaticity criteria," IEE Proceedings-J 138, 343-354 (1991).

Hill, K. O.

F. Bilodeau, K. O. Hill, S. Faucher, and D. C. Johnson, "Low-loss highly overcoupled fused couplers: Fabrication and sensitivity to external pressure," J. Lightwave Technol. 6, 1476- 1482 (1988).
[CrossRef]

Horak, P.

F. Xu, P. Horak, and G. Brambilla, "Optical microfiber coil resonator refractometric sensor," Opt. Express. 15, 7888-7893 (2007), http://www.opticsinfobase.org/abstract.cfm?URI=oe-15-12-7888.
[CrossRef] [PubMed]

Johnson, D. C.

F. Bilodeau, K. O. Hill, S. Faucher, and D. C. Johnson, "Low-loss highly overcoupled fused couplers: Fabrication and sensitivity to external pressure," J. Lightwave Technol. 6, 1476- 1482 (1988).
[CrossRef]

Jung, J. C.

B. A. Flusberg, E. D. Cocker, W. Piyawattanametha, J. C. Jung, E. L. M. Cheung, and M. J. Schnitzer, "Fiber-optic fluorescence imaging," Nat. Methods 2, 941-950 (2005).
[CrossRef] [PubMed]

Kim, D. Y.

S. Moon and D. Y. Kim, "Effective single-mode transmission at wavelengths shorter than the cutoff wavelength of an optical fiber," IEEE Photon. Technol. Lett. 17, 2604-2606 (2005).
[CrossRef]

Knight, J. C.

Lacroix, S.

R. J. Black, S. Lacroix, F. Gonthier, and J. D. Love, "Tapered single-mode fibres and devices - Part 2: Experimental and theoretical quantification," IEE Proceedings-J 138, 355-364 (1991).

J. D. Love, W. M. Henry, W. J. Stewart, R. J. Black, S. Lacroix, and F. Gonthier, "Tapered single-mode fibres and devices - Part 1: Adiabaticity criteria," IEE Proceedings-J 138, 343-354 (1991).

Lamont, M. R. E.

Le Kien, F.

V. I. Balykin, K. Hakuta, F. Le Kien, J. Q. Liang, and M. Morinaga, "Atom trapping and guiding with a subwavelength-diameter optical fiber," Phys. Rev. A 70, 011401 (2004).

Li, Y. W.

T. A. Birks and Y. W. Li, "The shape of fiber tapers," J. Lightwave Technol. 10, 432-438 (1992).
[CrossRef]

Liang, J. Q.

V. I. Balykin, K. Hakuta, F. Le Kien, J. Q. Liang, and M. Morinaga, "Atom trapping and guiding with a subwavelength-diameter optical fiber," Phys. Rev. A 70, 011401 (2004).

Lou, J.

L. Tong, J. Lou, and E. Mazur, "Single-mode guiding properties of subwavelength-diameter silica and silicon wire waveguides," Opt. Express 12, 1025-1035 (2004).
[CrossRef] [PubMed]

L. Tong, R. R. Gattass, J. B. Ashcom, S. He, J. Lou, M. Shen, I. Maxwell, and E. Mazur, "Subwavelength-diameter silica wires for low-loss optical wave guiding," Nature 426, 816-819 (2003).
[CrossRef] [PubMed]

Love, J. D.

R. J. Black, S. Lacroix, F. Gonthier, and J. D. Love, "Tapered single-mode fibres and devices - Part 2: Experimental and theoretical quantification," IEE Proceedings-J 138, 355-364 (1991).

J. D. Love, W. M. Henry, W. J. Stewart, R. J. Black, S. Lacroix, and F. Gonthier, "Tapered single-mode fibres and devices - Part 1: Adiabaticity criteria," IEE Proceedings-J 138, 343-354 (1991).

Mägi, E. C.

Maxwell, I.

L. Tong, R. R. Gattass, J. B. Ashcom, S. He, J. Lou, M. Shen, I. Maxwell, and E. Mazur, "Subwavelength-diameter silica wires for low-loss optical wave guiding," Nature 426, 816-819 (2003).
[CrossRef] [PubMed]

Mazur, E.

L. Tong, J. Lou, and E. Mazur, "Single-mode guiding properties of subwavelength-diameter silica and silicon wire waveguides," Opt. Express 12, 1025-1035 (2004).
[CrossRef] [PubMed]

L. Tong, R. R. Gattass, J. B. Ashcom, S. He, J. Lou, M. Shen, I. Maxwell, and E. Mazur, "Subwavelength-diameter silica wires for low-loss optical wave guiding," Nature 426, 816-819 (2003).
[CrossRef] [PubMed]

Moon, S.

S. Moon and D. Y. Kim, "Effective single-mode transmission at wavelengths shorter than the cutoff wavelength of an optical fiber," IEEE Photon. Technol. Lett. 17, 2604-2606 (2005).
[CrossRef]

Morinaga, M.

V. I. Balykin, K. Hakuta, F. Le Kien, J. Q. Liang, and M. Morinaga, "Atom trapping and guiding with a subwavelength-diameter optical fiber," Phys. Rev. A 70, 011401 (2004).

Nilson, J.

J. Nilson, W. A. Clarkson, R. Selvas, J. K. Sahu, P. W. Turner, S. -U. Alam, and A. B. Grudinin, "High-power wavelength-tunable cladding-pumped rare-earth-doped silica fiber lasers," Opt. Fiber Technol. 10, 5-30 (2004).
[CrossRef]

Piyawattanametha, W.

B. A. Flusberg, E. D. Cocker, W. Piyawattanametha, J. C. Jung, E. L. M. Cheung, and M. J. Schnitzer, "Fiber-optic fluorescence imaging," Nat. Methods 2, 941-950 (2005).
[CrossRef] [PubMed]

Richardson, D. J.

Roelens, M. A. F.

Russell, P. St. J.

Sahu, J. K.

J. Nilson, W. A. Clarkson, R. Selvas, J. K. Sahu, P. W. Turner, S. -U. Alam, and A. B. Grudinin, "High-power wavelength-tunable cladding-pumped rare-earth-doped silica fiber lasers," Opt. Fiber Technol. 10, 5-30 (2004).
[CrossRef]

Schnitzer, M. J.

B. A. Flusberg, E. D. Cocker, W. Piyawattanametha, J. C. Jung, E. L. M. Cheung, and M. J. Schnitzer, "Fiber-optic fluorescence imaging," Nat. Methods 2, 941-950 (2005).
[CrossRef] [PubMed]

Selvas, R.

J. Nilson, W. A. Clarkson, R. Selvas, J. K. Sahu, P. W. Turner, S. -U. Alam, and A. B. Grudinin, "High-power wavelength-tunable cladding-pumped rare-earth-doped silica fiber lasers," Opt. Fiber Technol. 10, 5-30 (2004).
[CrossRef]

Shen, M.

L. Tong, R. R. Gattass, J. B. Ashcom, S. He, J. Lou, M. Shen, I. Maxwell, and E. Mazur, "Subwavelength-diameter silica wires for low-loss optical wave guiding," Nature 426, 816-819 (2003).
[CrossRef] [PubMed]

Stewart, W. J.

J. D. Love, W. M. Henry, W. J. Stewart, R. J. Black, S. Lacroix, and F. Gonthier, "Tapered single-mode fibres and devices - Part 1: Adiabaticity criteria," IEE Proceedings-J 138, 343-354 (1991).

Sumetsky, M.

Tong, L.

L. Tong, J. Lou, and E. Mazur, "Single-mode guiding properties of subwavelength-diameter silica and silicon wire waveguides," Opt. Express 12, 1025-1035 (2004).
[CrossRef] [PubMed]

L. Tong, R. R. Gattass, J. B. Ashcom, S. He, J. Lou, M. Shen, I. Maxwell, and E. Mazur, "Subwavelength-diameter silica wires for low-loss optical wave guiding," Nature 426, 816-819 (2003).
[CrossRef] [PubMed]

Turner, P. W.

J. Nilson, W. A. Clarkson, R. Selvas, J. K. Sahu, P. W. Turner, S. -U. Alam, and A. B. Grudinin, "High-power wavelength-tunable cladding-pumped rare-earth-doped silica fiber lasers," Opt. Fiber Technol. 10, 5-30 (2004).
[CrossRef]

Wolfbeis, O. S.

O. S. Wolfbeis, "Fiber-optic chemical sensors and biosensors," Anal. Chem. 74, 2663-2678 (2002).
[CrossRef] [PubMed]

Xu, F.

F. Xu, P. Horak, and G. Brambilla, "Optical microfiber coil resonator refractometric sensor," Opt. Express. 15, 7888-7893 (2007), http://www.opticsinfobase.org/abstract.cfm?URI=oe-15-12-7888.
[CrossRef] [PubMed]

Yeom, D. -I.

Anal. Chem. (1)

O. S. Wolfbeis, "Fiber-optic chemical sensors and biosensors," Anal. Chem. 74, 2663-2678 (2002).
[CrossRef] [PubMed]

IEE Proceedings-J (2)

J. D. Love, W. M. Henry, W. J. Stewart, R. J. Black, S. Lacroix, and F. Gonthier, "Tapered single-mode fibres and devices - Part 1: Adiabaticity criteria," IEE Proceedings-J 138, 343-354 (1991).

R. J. Black, S. Lacroix, F. Gonthier, and J. D. Love, "Tapered single-mode fibres and devices - Part 2: Experimental and theoretical quantification," IEE Proceedings-J 138, 355-364 (1991).

IEEE Photon. Technol. Lett. (1)

S. Moon and D. Y. Kim, "Effective single-mode transmission at wavelengths shorter than the cutoff wavelength of an optical fiber," IEEE Photon. Technol. Lett. 17, 2604-2606 (2005).
[CrossRef]

J. Lightwave Technol. (3)

D. Donlagic, "In-line higher order mode filters based on long highly uniform fiber tapers," J. Lightwave Technol. 24, 3532-3539 (2006).
[CrossRef]

F. Bilodeau, K. O. Hill, S. Faucher, and D. C. Johnson, "Low-loss highly overcoupled fused couplers: Fabrication and sensitivity to external pressure," J. Lightwave Technol. 6, 1476- 1482 (1988).
[CrossRef]

T. A. Birks and Y. W. Li, "The shape of fiber tapers," J. Lightwave Technol. 10, 432-438 (1992).
[CrossRef]

Nat. Methods (1)

B. A. Flusberg, E. D. Cocker, W. Piyawattanametha, J. C. Jung, E. L. M. Cheung, and M. J. Schnitzer, "Fiber-optic fluorescence imaging," Nat. Methods 2, 941-950 (2005).
[CrossRef] [PubMed]

Nature (1)

L. Tong, R. R. Gattass, J. B. Ashcom, S. He, J. Lou, M. Shen, I. Maxwell, and E. Mazur, "Subwavelength-diameter silica wires for low-loss optical wave guiding," Nature 426, 816-819 (2003).
[CrossRef] [PubMed]

Opt. Express (3)

Opt. Express. (1)

F. Xu, P. Horak, and G. Brambilla, "Optical microfiber coil resonator refractometric sensor," Opt. Express. 15, 7888-7893 (2007), http://www.opticsinfobase.org/abstract.cfm?URI=oe-15-12-7888.
[CrossRef] [PubMed]

Opt. Fiber Technol. (1)

J. Nilson, W. A. Clarkson, R. Selvas, J. K. Sahu, P. W. Turner, S. -U. Alam, and A. B. Grudinin, "High-power wavelength-tunable cladding-pumped rare-earth-doped silica fiber lasers," Opt. Fiber Technol. 10, 5-30 (2004).
[CrossRef]

Opt. Lett. (3)

Phys. Rev. A (1)

V. I. Balykin, K. Hakuta, F. Le Kien, J. Q. Liang, and M. Morinaga, "Atom trapping and guiding with a subwavelength-diameter optical fiber," Phys. Rev. A 70, 011401 (2004).

Science (1)

P. St. J. Russell, "Photonic crystal fibers," Science 299, 358-362 (2003).
[CrossRef] [PubMed]

Other (1)

K. Okamoto, Fundamentals of Optical Waveguides (Elsevier Academic, London, 2006).

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 (4)

Fig. 1.
Fig. 1.

An idealized sub-wavelength optical wire (SOW) for higher-order mode filtering in a two mode optical fiber. (a) Adiabatic transition tapers provide continuous mode evolution from core modes to cladding modes, and vice versa. All modes launched into the fiber are collected at the fiber output. (b) The use of non-adiabatic tapers for higher-order core modes transfers power to higher-order cladding modes or radiation modes which are not guided by the SOW. Higher-order taper modes are effectively filtered out by controlling the SOW diameter.

Fig. 2.
Fig. 2.

Spectral response of the tapered fibers: (a) Transmission spectra of a 5m telecom fiber with a SOW for different SOW outer diameters. Interference between different modes occurs for tapers with 70µm diameter, while single mode operation is observed for the whole range of scanned wavelengths for tapers with 1µm diameter. (b) Comparison between the transmission spectra of a standard fiber (Corning SMF-28) without (in black) and with (in red) a 1µm SOW. λ c_ LP 11 represents the cut-off wavelength for the bi-lobed LP 11 mode which exists only for wavelengths shorter than λ c_ LP 11. Similarly, λ c_ LP 21 and λ c_ LP 02 represent the cut-offs for the higher order modes LP 21 and LP 02, respectively.

Fig. 3.
Fig. 3.

Far-field imaging of telecom fibers without (a,c,e) and with SOW (b,d,f) at a wavelength of 632.8nm (He-Ne laser) and 488 nm (Ar laser), respectively.

Fig. 4.
Fig. 4.

Effective index versus core guidance parameter V (=2π ρ NA/λ, where ρ is the SOW radius, NA the numerical aperture and λ the wavelength) for the first three (a) LP 0m and (b) LP 1m guided modes. n clad and n eff represent the cladding and the mode effective indices, respectively. The difference of effective indices between LP n0 and LP n1 modes allows the determination of the taper adiabatic angle Ω through equation 1. (c) Adiabatic profiles for LP 01 (black) and LP 11 (red) modes. The real taper profile has greater angles than the LP 11 adiabatic curve between inverse taper ratios ρ(z)/ρ 0 =0.65 and 0.8, meaning that the LP 11 mode will be converted in LP 1m (m>1) modes for ρ(z)/ρ 0 <0.8.

Equations (1)

Equations on this page are rendered with MathJax. Learn more.

Ω = ρ z = ρ ( β 1 β 2 ) 2 π

Metrics