Abstract

We have experimentally studied fundamental mode propagation in few meters long, adiabatically tapered step-index fibers with high numerical aperture, core diameter up to 117 μm (V = 38) and tapering ratio up to 18. The single fundamental mode propagation was confirmed by several techniques that reveal no signature of higher-order mode excitation. It can be, therefore, concluded that adiabatic tapering is a powerful method for selective excitation of the fundamental mode in highly multimode large-mode-area fibers. Annular near field distortion observed for large output core diameters was attributed to built-in stress due to thermal expansion mismatch between core and cladding materials. The mechanical stress could be avoided by an appropriate technique of fiber preform fabrication and drawing, which would prevent the mode field deformation and lead to reliable diffraction-limited fundamental mode guiding for very large core diameters.

© 2012 OSA

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References

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  4. J. Limpert, A. Liem, M. Reich, T. Schreiber, S. Nolte, H. Zellmer, A. Tünnermann, J. Broeng, A. Petersson, and C. Jakobsen, “Low-nonlinearity single-transverse-mode ytterbium-doped photonic crystal fiber amplifier,” Opt. Express 12(7), 1313–1319 (2004).
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    [Crossref] [PubMed]
  17. V. Filippov, Y. Chamorovskii, J. Kerttula, A. Kholodkov, and O. G. Okhotnikov, “600 W power scalable single transverse mode tapered double-clad fiber laser,” Opt. Express 17(3), 1203–1214 (2009).
    [Crossref] [PubMed]
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    [Crossref] [PubMed]
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    [Crossref]
  25. P. M. Shankar, L. C. Bobb, and H. D. Krumboltz, “Coupling of modes in bent biconically tapered single-mode fibers,” J. Lightwave Technol. 9(7), 832–837 (1991).
    [Crossref]
  26. L. C. Bobb, P. M. Shankar, and H. D. Krumboltz, “Bending effects in biconically tapered single-mode fibers,” J. Lightwave Technol. 8(7), 1084–1090 (1990).
    [Crossref]
  27. D. Donlagic and B. Culshaw, “Propagation of the fundamental mode in curved graded index multimode fiber and its application in sensor systems,” J. Lightwave Technol. 18(3), 334–342 (2000).
    [Crossref]
  28. F. Just, H.-R. Müller, S. Unger, J. Kirchhof, V. Reichel, and H. Bartelt, “Ytterbium-Doping Related Stresses in Preforms for High-Power Fiber Lasers,” J. Lightwave Technol. 27(12), 2111–2116 (2009).
    [Crossref]
  29. J. W. Dawson, M. J. Messerly, R. J. Beach, M. Y. Shverdin, E. A. Stappaerts, A. K. Sridharan, P. H. Pax, J. E. Heebner, C. W. Siders, and C. P. Barty, “Analysis of the scalability of diffraction-limited fiber lasers and amplifiers to high average power,” Opt. Express 16(17), 13240–13266 (2008).
    [Crossref] [PubMed]

2012 (1)

2011 (1)

2010 (1)

2009 (4)

2008 (3)

2007 (3)

2006 (1)

2004 (2)

2000 (2)

1998 (1)

1991 (1)

P. M. Shankar, L. C. Bobb, and H. D. Krumboltz, “Coupling of modes in bent biconically tapered single-mode fibers,” J. Lightwave Technol. 9(7), 832–837 (1991).
[Crossref]

1990 (1)

L. C. Bobb, P. M. Shankar, and H. D. Krumboltz, “Bending effects in biconically tapered single-mode fibers,” J. Lightwave Technol. 8(7), 1084–1090 (1990).
[Crossref]

1988 (1)

O. E. Shushpanov, A. N. Tuzov, I. V. Alexsandrov, S. P. Vikulov, M. E. Zhabotinskii, V. V. Romanovtzev, and S. J. Feld, “An automated system for measurement of mechanical stresses in optical fiber preforms with polarization-optical method,” Radiotechnika 43, 67–72 (1988) (in Russian).

1987 (2)

N. Amitay, H. Presby, F. DiMarcello, and K. Nelson, “Optical fiber tapers–A novel approach to self-aligned beam expansion and single-mode hardware,” J. Lightwave Technol. 5(1), 70–76 (1987).
[Crossref]

D. Marcuse, “Mode conversion in optical fibers with monotonically increasing core radius,” J. Lightwave Technol. 5(1), 125–133 (1987).
[Crossref]

1980 (1)

1970 (1)

A. W. Snyder, “Coupling of modes on a tapered dielectric cylinder,” IEEE Trans. Microw. Theory Tech. 18(7), 383–392 (1970).
[Crossref]

Alexsandrov, I. V.

O. E. Shushpanov, A. N. Tuzov, I. V. Alexsandrov, S. P. Vikulov, M. E. Zhabotinskii, V. V. Romanovtzev, and S. J. Feld, “An automated system for measurement of mechanical stresses in optical fiber preforms with polarization-optical method,” Radiotechnika 43, 67–72 (1988) (in Russian).

Amitay, N.

N. Amitay, H. Presby, F. DiMarcello, and K. Nelson, “Optical fiber tapers–A novel approach to self-aligned beam expansion and single-mode hardware,” J. Lightwave Technol. 5(1), 70–76 (1987).
[Crossref]

Banerji, J.

C. D. Stacey, R. M. Jenkins, J. Banerji, and A. R. Davies, “Demonstration of fundamental mode only propagation in highly multimode fibre for high power EDFAs,” Opt. Commun. 269(2), 310–314 (2007).
[Crossref]

Bartelt, H.

Barty, C. P.

Beach, R. J.

Bobb, L. C.

P. M. Shankar, L. C. Bobb, and H. D. Krumboltz, “Coupling of modes in bent biconically tapered single-mode fibers,” J. Lightwave Technol. 9(7), 832–837 (1991).
[Crossref]

L. C. Bobb, P. M. Shankar, and H. D. Krumboltz, “Bending effects in biconically tapered single-mode fibers,” J. Lightwave Technol. 8(7), 1084–1090 (1990).
[Crossref]

Brambilla, G.

Broeng, J.

Chamorovskii, Y.

Chauny, L.-A.

Culshaw, B.

Davies, A. R.

C. D. Stacey, R. M. Jenkins, J. Banerji, and A. R. Davies, “Demonstration of fundamental mode only propagation in highly multimode fibre for high power EDFAs,” Opt. Commun. 269(2), 310–314 (2007).
[Crossref]

Dawson, J. W.

DiMarcello, F.

N. Amitay, H. Presby, F. DiMarcello, and K. Nelson, “Optical fiber tapers–A novel approach to self-aligned beam expansion and single-mode hardware,” J. Lightwave Technol. 5(1), 70–76 (1987).
[Crossref]

Dimarcello, F. V.

Dong, L.

Donlagic, D.

El-Rabii, H.

Ermeneux, S.

Feld, S. J.

O. E. Shushpanov, A. N. Tuzov, I. V. Alexsandrov, S. P. Vikulov, M. E. Zhabotinskii, V. V. Romanovtzev, and S. J. Feld, “An automated system for measurement of mechanical stresses in optical fiber preforms with polarization-optical method,” Radiotechnika 43, 67–72 (1988) (in Russian).

Fermann, M. E.

Filippov, V.

Gaylord, T. K.

Ghalmi, S.

Golant, K.

Goldberg, L.

Heebner, J. E.

Hurand, S.

Hutsel, M. R.

Ingle, R.

Jakobsen, C.

Jansen, F.

Jauregui, C.

Jenkins, R. M.

C. D. Stacey, R. M. Jenkins, J. Banerji, and A. R. Davies, “Demonstration of fundamental mode only propagation in highly multimode fibre for high power EDFAs,” Opt. Commun. 269(2), 310–314 (2007).
[Crossref]

Jeong, Y.

Joshi, S.

Jung, Y.

Just, F.

Kerttula, J.

Kholodkov, A.

Kirchhof, J.

Kliner, D. A. V.

Koplow, J. P.

Krumboltz, H. D.

P. M. Shankar, L. C. Bobb, and H. D. Krumboltz, “Coupling of modes in bent biconically tapered single-mode fibers,” J. Lightwave Technol. 9(7), 832–837 (1991).
[Crossref]

L. C. Bobb, P. M. Shankar, and H. D. Krumboltz, “Bending effects in biconically tapered single-mode fibers,” J. Lightwave Technol. 8(7), 1084–1090 (1990).
[Crossref]

Li, J.

Liem, A.

Limpert, J.

Linke, S.

Marcuse, D.

D. Marcuse, “Mode conversion in optical fibers with monotonically increasing core radius,” J. Lightwave Technol. 5(1), 125–133 (1987).
[Crossref]

Messerly, M. J.

Monberg, E.

Müller, H.-R.

Nelson, K.

N. Amitay, H. Presby, F. DiMarcello, and K. Nelson, “Optical fiber tapers–A novel approach to self-aligned beam expansion and single-mode hardware,” J. Lightwave Technol. 5(1), 70–76 (1987).
[Crossref]

Nicholson, J. W.

Nilsson, J.

Nolte, S.

Okhotnikov, O. G.

Pax, P. H.

Payne, D.

Peng, X.

Pessa, M.

Petersson, A.

Presby, H.

N. Amitay, H. Presby, F. DiMarcello, and K. Nelson, “Optical fiber tapers–A novel approach to self-aligned beam expansion and single-mode hardware,” J. Lightwave Technol. 5(1), 70–76 (1987).
[Crossref]

Rademaker, K.

Ramachandran, S.

Reich, M.

Reichel, V.

Richardson, D. J.

Romanovtzev, V. V.

O. E. Shushpanov, A. N. Tuzov, I. V. Alexsandrov, S. P. Vikulov, M. E. Zhabotinskii, V. V. Romanovtzev, and S. J. Feld, “An automated system for measurement of mechanical stresses in optical fiber preforms with polarization-optical method,” Radiotechnika 43, 67–72 (1988) (in Russian).

Röser, F.

Rothhardt, J.

Sahu, J.

Salin, F.

Scherer, G. W.

Schmidt, O.

Schreiber, T.

Shankar, P. M.

P. M. Shankar, L. C. Bobb, and H. D. Krumboltz, “Coupling of modes in bent biconically tapered single-mode fibers,” J. Lightwave Technol. 9(7), 832–837 (1991).
[Crossref]

L. C. Bobb, P. M. Shankar, and H. D. Krumboltz, “Bending effects in biconically tapered single-mode fibers,” J. Lightwave Technol. 8(7), 1084–1090 (1990).
[Crossref]

Shushpanov, O. E.

O. E. Shushpanov, A. N. Tuzov, I. V. Alexsandrov, S. P. Vikulov, M. E. Zhabotinskii, V. V. Romanovtzev, and S. J. Feld, “An automated system for measurement of mechanical stresses in optical fiber preforms with polarization-optical method,” Radiotechnika 43, 67–72 (1988) (in Russian).

Shverdin, M. Y.

Siders, C. W.

Snyder, A. W.

A. W. Snyder, “Coupling of modes on a tapered dielectric cylinder,” IEEE Trans. Microw. Theory Tech. 18(7), 383–392 (1970).
[Crossref]

Sridharan, A. K.

Stacey, C. D.

C. D. Stacey, R. M. Jenkins, J. Banerji, and A. R. Davies, “Demonstration of fundamental mode only propagation in highly multimode fibre for high power EDFAs,” Opt. Commun. 269(2), 310–314 (2007).
[Crossref]

Stappaerts, E. A.

Stutzki, F.

Tünnermann, A.

Tuzov, A. N.

O. E. Shushpanov, A. N. Tuzov, I. V. Alexsandrov, S. P. Vikulov, M. E. Zhabotinskii, V. V. Romanovtzev, and S. J. Feld, “An automated system for measurement of mechanical stresses in optical fiber preforms with polarization-optical method,” Radiotechnika 43, 67–72 (1988) (in Russian).

Unger, S.

Vikulov, S. P.

O. E. Shushpanov, A. N. Tuzov, I. V. Alexsandrov, S. P. Vikulov, M. E. Zhabotinskii, V. V. Romanovtzev, and S. J. Feld, “An automated system for measurement of mechanical stresses in optical fiber preforms with polarization-optical method,” Radiotechnika 43, 67–72 (1988) (in Russian).

Wisk, P.

Yablon, A. D.

Yalin, A. P.

Yan, M. F.

Yvernault, P.

Zellmer, H.

Zhabotinskii, M. E.

O. E. Shushpanov, A. N. Tuzov, I. V. Alexsandrov, S. P. Vikulov, M. E. Zhabotinskii, V. V. Romanovtzev, and S. J. Feld, “An automated system for measurement of mechanical stresses in optical fiber preforms with polarization-optical method,” Radiotechnika 43, 67–72 (1988) (in Russian).

Appl. Opt. (3)

IEEE Trans. Microw. Theory Tech. (1)

A. W. Snyder, “Coupling of modes on a tapered dielectric cylinder,” IEEE Trans. Microw. Theory Tech. 18(7), 383–392 (1970).
[Crossref]

J. Lightwave Technol. (6)

D. Marcuse, “Mode conversion in optical fibers with monotonically increasing core radius,” J. Lightwave Technol. 5(1), 125–133 (1987).
[Crossref]

P. M. Shankar, L. C. Bobb, and H. D. Krumboltz, “Coupling of modes in bent biconically tapered single-mode fibers,” J. Lightwave Technol. 9(7), 832–837 (1991).
[Crossref]

L. C. Bobb, P. M. Shankar, and H. D. Krumboltz, “Bending effects in biconically tapered single-mode fibers,” J. Lightwave Technol. 8(7), 1084–1090 (1990).
[Crossref]

D. Donlagic and B. Culshaw, “Propagation of the fundamental mode in curved graded index multimode fiber and its application in sensor systems,” J. Lightwave Technol. 18(3), 334–342 (2000).
[Crossref]

F. Just, H.-R. Müller, S. Unger, J. Kirchhof, V. Reichel, and H. Bartelt, “Ytterbium-Doping Related Stresses in Preforms for High-Power Fiber Lasers,” J. Lightwave Technol. 27(12), 2111–2116 (2009).
[Crossref]

N. Amitay, H. Presby, F. DiMarcello, and K. Nelson, “Optical fiber tapers–A novel approach to self-aligned beam expansion and single-mode hardware,” J. Lightwave Technol. 5(1), 70–76 (1987).
[Crossref]

J. Opt. Soc. Am. B (1)

Opt. Commun. (1)

C. D. Stacey, R. M. Jenkins, J. Banerji, and A. R. Davies, “Demonstration of fundamental mode only propagation in highly multimode fibre for high power EDFAs,” Opt. Commun. 269(2), 310–314 (2007).
[Crossref]

Opt. Express (7)

Y. Jeong, J. Sahu, D. Payne, and J. Nilsson, “Ytterbium-doped large-core fiber laser with 1.36 kW continuous-wave output power,” Opt. Express 12(25), 6088–6092 (2004).
[Crossref] [PubMed]

J. Limpert, A. Liem, M. Reich, T. Schreiber, S. Nolte, H. Zellmer, A. Tünnermann, J. Broeng, A. Petersson, and C. Jakobsen, “Low-nonlinearity single-transverse-mode ytterbium-doped photonic crystal fiber amplifier,” Opt. Express 12(7), 1313–1319 (2004).
[Crossref] [PubMed]

V. Filippov, Y. Chamorovskii, J. Kerttula, K. Golant, M. Pessa, and O. G. Okhotnikov, “Double clad tapered fiber for high power applications,” Opt. Express 16(3), 1929–1944 (2008).
[Crossref] [PubMed]

V. Filippov, Y. Chamorovskii, J. Kerttula, A. Kholodkov, and O. G. Okhotnikov, “600 W power scalable single transverse mode tapered double-clad fiber laser,” Opt. Express 17(3), 1203–1214 (2009).
[Crossref] [PubMed]

J. Kerttula, V. Filippov, Y. Chamorovskii, K. Golant, and O. G. Okhotnikov, “Actively Q-switched 1.6-mJ tapered double-clad ytterbium-doped fiber laser,” Opt. Express 18(18), 18543–18549 (2010).
[Crossref] [PubMed]

J. W. Nicholson, A. D. Yablon, S. Ramachandran, and S. Ghalmi, “Spatially and spectrally resolved imaging of modal content in large-mode-area fibers,” Opt. Express 16(10), 7233–7243 (2008).
[Crossref] [PubMed]

J. W. Dawson, M. J. Messerly, R. J. Beach, M. Y. Shverdin, E. A. Stappaerts, A. K. Sridharan, P. H. Pax, J. E. Heebner, C. W. Siders, and C. P. Barty, “Analysis of the scalability of diffraction-limited fiber lasers and amplifiers to high average power,” Opt. Express 16(17), 13240–13266 (2008).
[Crossref] [PubMed]

Opt. Lett. (6)

Radiotechnika (1)

O. E. Shushpanov, A. N. Tuzov, I. V. Alexsandrov, S. P. Vikulov, M. E. Zhabotinskii, V. V. Romanovtzev, and S. J. Feld, “An automated system for measurement of mechanical stresses in optical fiber preforms with polarization-optical method,” Radiotechnika 43, 67–72 (1988) (in Russian).

Other (3)

V. Fomin, M. Abramov, A. Ferin, A. Abramov, D. Mochalov, N. Platonov, and V. Gapontsev, “10 kW single-mode fiber laser,” presented at the Fifth International Symposium on High-Power Fiber Lasers and Their Applications, St. Petersburg, Russia, 28 Jun. - 1 Jul. 2010.

Y. Jung, G. Brambilla, and D. Richardson, “Efficient higher-order mode filtering in multimode optical fiber based on an optical microwire,” in Asia Optical Fiber Communication and Optoelectronic Exposition and Conference, OSA Technical Digest (CD) (Optical Society of America, 2008), paper SuB4.

J. Kerttula, V. Filippov, Y. Chamorovskii, V. Ustimchik, K. Golant, and O. G. Okhotnikov, “Theoretical and experimental comparison of different configurations of tapered fiber lasers,” in Conference on Lasers and Electro-Optics/European Quantum Electronics Conference, Technical Digest (CD) (Optical Society of America, 2011), paper CJ1_6.

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Figures (8)

Fig. 1
Fig. 1

Outer diameters (left axis) and core diameters (right axis) versus length of 7-m and 20-m tapers.

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Fig. 2
Fig. 2

(a) The core diameters and near field output beam profiles (2-D picture and 1-D graphs for two orthogonal axes) at different cut lengths measured from the large diameter output for straight 7-m taper. Bending or tension applied on the relatively rigid wide part of the taper resulted in a shift of the field distribution as shown in the second and third rows. (b) The far field beam profiles for the largest and smallest core diameters with Gaussian fits (red) in the 1-D profiles. Significant changes in the far field distribution were not observed at any output core diameter with any bending. (c) Far field (left) and near field (right) beam profiles for the uncut coiled 20-m taper.

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Fig. 3
Fig. 3

The output beam divergence (a) and M2 (b) versus core diameter for straight and coiled 7-m taper.

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Fig. 4
Fig. 4

(a) The far field beam profiles from 117-μm output core for narrow-to-wide propagated green (left) and infrared (right) emission through the 7-m taper. (b) The near field beam profiles after propagation through the 30-cm fiber section cut from the 7-m taper with core diameter increasing from 90 μm to 117 μm. The butt-coupled SM input launching was centered for lowest order mode excitation achievable (left) or off-center core excitation (right).

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Fig. 5
Fig. 5

(a) Transmission through a polarizer for the SM diode emission, and after narrow-to-wide propagation through coiled and uncoiled 7-m taper.

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Fig. 6
Fig. 6

Intermodal group delay spectrum normalized to fiber length for narrow-to-wide propagated broadband input. The insets show the optical spectra of the source before and after the 20-m taper, and an example location of the SM fiber (spatial filter) butt-coupled to the wide end taper core.

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Fig. 7
Fig. 7

The spatial distribution of linearly polarized white light propagated through a 37-mm taper section (117 μm core diameter) cut from the wide end of the 7-m taper (top left), and the same output after a crossed polarizer (top right). Bottom row: the same measurements after annealing of the fiber piece for 4 h at 1000 °C.

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Fig. 8
Fig. 8

The axial stress component (left axis) and the corresponding lower limit estimation of the stress-induced refractive index change (right axis).

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Table 1 Polarization measurements.

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