Abstract

Enabling Single-Mode (SM) operation in Large-Mode-Area (LMA) fiber amplifiers and lasers is critical, since a SM output ensures high beam quality and excellent pointing stability. In this paper, we demonstrate and test a new design approach for achieving SM LMA rod fibers by using a photonic bandgap structure. The structure allows resonant coupling of higher-order modes from the core and acts as a spatially Distributed Mode Filter (DMF). With this approach, we demonstrate passive SM performance in an only ~50cm long and straight ytterbium-doped rod fiber. The amplifier has a mode field diameter of ~59µm at 1064nm and exhibits a pump absorption of 27dB/m at 976nm.

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References

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  1. C. D. Brooks and F. Di Teodoro, “Multi-megawatt peak-power, single-transverse-mode operation of a 100 µm core diameter, Yb-doped rod-like photonic crystal fiber amplifier,” Appl. Phys. Lett. 89(11), 111119 (2006).
    [CrossRef]
  2. J. Limpert, O. Schmidt, J. Rothhardt, F. Röser, T. Schreiber, A. Tünnermann, S. Ermeneux, P. Yvernault, and F. Salin, “Extended single-mode photonic crystal fiber lasers,” Opt. Express 14(7), 2715–2720 (2006).
    [CrossRef] [PubMed]
  3. J. P. Koplow, D. A. V. Kliner, and L. Goldberg, “Single-mode operation of a coiled multimode fiber amplifier,” Opt. Lett. 25(7), 442–444 (2000).
    [CrossRef]
  4. C. Liu, G. Chang, N. Litchinister, D. Guertin, N. Jacobson, K. Tankala, and A. Galvanauskas, “Chirally coupled core fibers at 1550-nm and 1064-nm for effectively single-mode core size scaling,” in Conference on Lasers and Electro-Optics/Quantum Electronics and Laser Science Conference and Photonic Applications Systems Technologies, OSA Technical Digest Series (CD) (Optical Society of America, 2007), paper CTuBB3.
  5. L. Dong, H. A. McKay, L. Fu, M. Ohta, A. Marcinkevicius, S. Suzuki, and M. E. Fermann, “Ytterbium-doped all glass leakage channel fibers with highly fluorine-doped silica pump cladding,” Opt. Express 17(11), 8962–8969 (2009).
    [CrossRef] [PubMed]
  6. M. E. Fermann, “Single-mode excitation of multimode fibers with ultrashort pulses,” Opt. Lett. 23(1), 52–54 (1998).
    [CrossRef]
  7. J. W. Nicholson, J. M. Fini, A. M. DeSantolo, E. Monberg, F. DiMarcello, J. Fleming, C. Headley, D. J. DiGiovanni, S. Ghalmi, and S. Ramachandran, “A higher-order-mode erbium-doped-fiber amplifier,” Opt. Express 18(17), 17651–17657 (2010).
    [CrossRef] [PubMed]
  8. F. Jansen, F. Stutzki, H.-J. Otto, M. Baumgartl, C. Jauregui, J. Limpert, and A. Tünnermann, “The influence of index-depressions in core-pumped Yb-doped large pitch fibers,” Opt. Express 18(26), 26834–26842 (2010).
    [CrossRef]
  9. N. Mortensen and J. Folkenberg, “Near-field to far-field transition of photonic crystal fibers: symmetries and interference phenomena,” Opt. Express 10(11), 475–481 (2002).
    [PubMed]

2010 (2)

2009 (1)

2006 (2)

C. D. Brooks and F. Di Teodoro, “Multi-megawatt peak-power, single-transverse-mode operation of a 100 µm core diameter, Yb-doped rod-like photonic crystal fiber amplifier,” Appl. Phys. Lett. 89(11), 111119 (2006).
[CrossRef]

J. Limpert, O. Schmidt, J. Rothhardt, F. Röser, T. Schreiber, A. Tünnermann, S. Ermeneux, P. Yvernault, and F. Salin, “Extended single-mode photonic crystal fiber lasers,” Opt. Express 14(7), 2715–2720 (2006).
[CrossRef] [PubMed]

2002 (1)

2000 (1)

1998 (1)

Baumgartl, M.

Brooks, C. D.

C. D. Brooks and F. Di Teodoro, “Multi-megawatt peak-power, single-transverse-mode operation of a 100 µm core diameter, Yb-doped rod-like photonic crystal fiber amplifier,” Appl. Phys. Lett. 89(11), 111119 (2006).
[CrossRef]

DeSantolo, A. M.

Di Teodoro, F.

C. D. Brooks and F. Di Teodoro, “Multi-megawatt peak-power, single-transverse-mode operation of a 100 µm core diameter, Yb-doped rod-like photonic crystal fiber amplifier,” Appl. Phys. Lett. 89(11), 111119 (2006).
[CrossRef]

DiGiovanni, D. J.

DiMarcello, F.

Dong, L.

Ermeneux, S.

Fermann, M. E.

Fini, J. M.

Fleming, J.

Folkenberg, J.

Fu, L.

Ghalmi, S.

Goldberg, L.

Headley, C.

Jansen, F.

Jauregui, C.

Kliner, D. A. V.

Koplow, J. P.

Limpert, J.

Marcinkevicius, A.

McKay, H. A.

Monberg, E.

Mortensen, N.

Nicholson, J. W.

Ohta, M.

Otto, H.-J.

Ramachandran, S.

Röser, F.

Rothhardt, J.

Salin, F.

Schmidt, O.

Schreiber, T.

Stutzki, F.

Suzuki, S.

Tünnermann, A.

Yvernault, P.

Appl. Phys. Lett. (1)

C. D. Brooks and F. Di Teodoro, “Multi-megawatt peak-power, single-transverse-mode operation of a 100 µm core diameter, Yb-doped rod-like photonic crystal fiber amplifier,” Appl. Phys. Lett. 89(11), 111119 (2006).
[CrossRef]

Opt. Express (5)

Opt. Lett. (2)

Other (1)

C. Liu, G. Chang, N. Litchinister, D. Guertin, N. Jacobson, K. Tankala, and A. Galvanauskas, “Chirally coupled core fibers at 1550-nm and 1064-nm for effectively single-mode core size scaling,” in Conference on Lasers and Electro-Optics/Quantum Electronics and Laser Science Conference and Photonic Applications Systems Technologies, OSA Technical Digest Series (CD) (Optical Society of America, 2007), paper CTuBB3.

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Figures (14)

Fig. 1
Fig. 1

Effective mode index of the LP11 HOM mode of a 85µm core hexagonal rod amplifier as function of relative hole diameter (d/Λ) and doping level of the core elements.

Fig. 2
Fig. 2

Modal LP11 indices, as in Fig. 1, and FSM for the hexagonal cladding (FSMhex) and for a honeycomb-type cladding structure having pure silica elements (FSMhoney0) and + 3e-4 updoped elements(FSMhoney3).

Fig. 3
Fig. 3

Schematic and microscope image of a DMF element having a central air hole surrounded by a high-index germanium ring with index n2 and an outer silica shell with index n3.

Fig. 4
Fig. 4

Schematic of rod fiber design with DMF elements arranged in a hexagonal lattice (a) and in a honeycomb-type lattice (b).

Fig. 5
Fig. 5

Modal LP11 indices as in Fig. 1a and the FSM of the DMF elements arranged in a hexagonal (FSMDMF-HEX) and in a honeycomb-type lattice (FSMDMF-HONEY).

Fig. 6
Fig. 6

Finite element simulation of the structure illustrated in Fig. 4b. Figure shows the effective modal index of the FM and the first HOM/cladding mode. At approx. d/Λ~0.195, the cladding modes formed by the DMF is phase-matched to the HOM and only the FM is supported for 0.175<d/Λ<0.195.

Fig. 7
Fig. 7

Simulated modal fields of the modal evolution FM (top row) and HOM (bottom row) of the rod fiber as d/Λ is decreased from 0.2 to 0.175.

Fig. 8
Fig. 8

Mode beating spectrum of a passive 85µm core DMF rod fiber. Inset shows a microscope image of the rod fiber.

Fig. 9
Fig. 9

Measured SM region of the 85µm core DMF rod fiber shown in the inset of Fig. 8 as function of the relative hole diameter of the hole in the DMF element.

Fig. 10
Fig. 10

Near field images of the passive DMF rod fiber at 1064nm wavelength. Images show the near field as the input beam is translated along x (top row) and y (bottom row) direction.

Fig. 11
Fig. 11

Near field image of a passive 100µm core DMF rod at 1224nm wavelength. The mode field diameter was measured to 72.5µm at 1224nm.

Fig. 12
Fig. 12

Near field images of the ytterbium-doped DMF rod fiber at 1064nm wavelength. Images show the near field as the input beam is translated along x (top row) and y (bottom row) direction.

Fig. 13
Fig. 13

Near field images of the 40cm long rod when the input beam is misaligned along the transversal direction and a slightly asymmetric mode is excited (a) and with optimum aligned input beam the FM is excited (b).

Fig. 14
Fig. 14

Near field of the 120cm rod with a collapsed output zone of ~60µm (a), near field to far field transition of the field (b), far field of the FM (c).

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