C. Jauregui, J. Limpert, A. Tünnermann, "High power fibre lasers
," Nat. Photon. 7, 861-867 (2013).

J. M. Fini, J. W. Nicholson, R. S. Windeler, E. M. Monberg, L.
Meng, B. Mangan, A. DeSantolo, F. V. DiMarcello, "Low-loss hollow-core fibers with improved
single-modedness," Opt. Exp. 21, 6233-6242 (2013).

J. F. Bauters, M. L. Davenport, M. J. R. Heck, J. K. Doylend, A.
Chen, A. W. Fang, J. E. Bowers, "Silicon on ultra-low-loss waveguide photonic integration
platform," Opt. Exp. 21, 544-555 (2013).

G. Gu, F. Kong, T. W. Hawkins, P. Foy, K. Wei, B. Samson, L.
Dong, "Impact of fiber outer boundaries on leaky mode losses in leakage channel fibers,"
Opt. Exp. 21, 24039-24048 (2013).

C. Schulze, A. Lorenz, D. Flamm, A. Hartung, S. Schröter, H.
Bartelt, M. Duparré, "Mode resolved bend loss in few-mode optical fibers," Opt. Exp. 21,
3170-3181 (2013).

S. Shwartz, M. Golub, S. Ruschin, "Diffractive optical elements
for mode-division multiplexing of temporal signals with the aid of Laguerre–Gaussian modes,"
Appl. Opt. 52, 2659-2669 (2013).

D. Flamm, C. Schulze, D. Naidoo, S. Schröter, A. Forbes, M.
Duparré, "All-digital tool for mode excitation and analysis in optical fibers," IEEE J.
Lightw. Tech. 31, 1023-1032 (2013).

D. Flamm, K.-C. Hou, P. Gelszinnis, C. Schulze, S. Schröter, M.
Duparré, "Modal characterization of fiber-to-fiber coupling processes," Opt. Lett. 38,
2128-2130 (2013).

H. J. Otto, F. Jansen, F. Stutzki, C. Jauregui, J. Limpert, A.
Tünnermann, "Improved modal reconstruction for spatially and spectrally resolved imaging,"
IEEE J. Lightw. Tech. 31, 1295-1299 (2013).

D. Flamm, D. Naidoo, C. Schulze, A. Forbes, M. Duparré, "Mode
analysis with a spatial light modulator as a correlation filter," Opt. Lett. 37, 2478-2480
(2012).

D. M. Nguyen, S. Blin, T. N. Nguyen, S. D. Le, L. Provino, M.
Thual, T. Chartier, "Modal decomposition technique for multimode fibers," Appl. Opt. 51,
450-456 (2012).

A. Dudley, I. A. Litvin, A. Forbes, "Quantitative measurement of
the orbital angular momentum density of light," Appl. Opt. 51, 823-833
(2012).

D. Flamm, C. Schulze, R. Brüning, O. A. Schmidt, T. Kaiser, S.
Schröter, M. Duparré, "Fast
$M^{2}$
measurement for fiber beams based on mode analysis," Appl. Opt. 51,
987-993 (2012).

C. Schulze, D. Naidoo, D. Flamm, O. A. Schmidt, A. Forbes, M.
Duparré, "Wavefront reconstruction by modal decomposition," Opt. Exp. 20, 19714-19725
(2012).

J. Jasapara, A. D. Yablon, "Spectrogram approach to
$S^{2}$
fiber mode analysis to distinguish between dispersion and distributed
scattering," Opt. Lett. 37, 3906-3908 (2012).

J. W. Nicholson, L. Meng, J. M. Fini, R. S. Windeler, A.
DeSantolo, E. Monberg, F. DiMarcello, Y. Dulashko, M. Hassan, R. Ortiz, "Measuring
higher-order modes in a low-loss, hollow-core, photonic-bandgap fiber ," Opt. Exp. 20,
20494-20505 (2012).

P. Kadwani, C. Jollivet, R. A. Sims, A. Schülzgen, L. Shah, M.
Richardson, "Comparison of higher-order mode suppression and Q-switched laser performances
in thulium-doped large mode area and photonic crystal fibers," Opt. Exp. 20, 24295-24303
(2012).

J. Kerttula, V. Filippov, V. Ustimchik, Y. Chamorovskiy, O. G.
Okhotnikov, "Mode evolution in long tapered fibers with high tapering ratio," Opt. Exp. 20,
25461-25470 (2012).

F. Stutzki, F. Jansen, A. Liem, C. Jauregui, J. Limpert, A.
Tünnermann, "26 mJ, 130 W Q-switched fiber-laser system with near-diffraction-limited beam
quality," Opt. Lett. 37, 1073-1075 (2012).

C. Jauregui, T. Eidam, H.-J. Otto, F. Stutzki, F. Jansen, J.
Limpert, A. Tünnermann, "Temperature-induced index gratings and their impact on mode
instabilities in high-power fiber laser systems," Opt. Exp. 20, 440-451
(2012).

F. Kong, K. Saitoh, D. Mcclane, T. Hawkins, P. Foy, G. Gu, L.
Dong, "Mode area scaling with all-solid photonic bandgap fibers," Opt. Exp. 20, 26363-26372
(2012).

J. Bromage, J. M. Fini, C. Dorrer, J. D. Zuegel,
"Characterization and optimization of Yb-doped photonic-crystal fiber rod amplifier using
spatially resolved spectral interferometry," App. Opt. 50, 2001-2007 (2011).

D. N. Schimpf, R. A. Barankov, S. Ramachandran,
"Cross-correlated (C2) imaging of fiber and waveguide modes," Opt. Exp. 19, 13008-13019
(2011).

F. Stutzki, H.-J. Otto, F. Jansen, C. Gaida, C. Jauregui, J.
Limpert, A. Tünnermann, "High-speed modal decomposition of mode instabilities in high-power
fiber lasers ," Opt. Lett. 36, 4572-4574 (2011).

T. Bilici, S. Mutlu, H. Kalaycioqlu, A. Kurt, A. Sennaroqlu, M.
Gulsoy, "Development of a thulium (Tm:YAP) laser system for brain tissue ablation," Las.
Med. Sci. 26, 699-706 (2011).

F. Stutzki, F. Jansen, T. Eidam, A. Steinmetz, C. Jauregui, J.
Limpert, A. Tünnermann, "High average power large-pitch fiber amplifier with robust
single-mode operation," Opt. Lett. 36, 689-691 (2011).

D. J. Richardson, J. Nilsson, W. Clarkson, "High power fiber
lasers: Current status and future perspectives," J. Opt. Soc. Amer. B 27 , B63-B92 (2010
).

P. Sprangle, A. Ting, J. Peñano, R. Fischer, B. Hafizi, "
Incoherent combining and atmospheric propagation of high-power fiber lasers for
directed-energy applications ," IEEE J. Quantum Electron. 45, 138-148
(2009).

Y. Z. Ma, Y. Sych, G. Onishchukov, S. Ramachandran, U. Peschel,
B. Schmauss, G. Leuchs, "Fiber-modes and fiber anisotropy characterization using
low-coherence interferometry," Appl. Phys. B 96, 345 -353 (2009).

T. Kaiser, D. Flamm, S. Schröter, M. Duparré, "Complete modal
decomposition for optical fibers using CGH-based correlation filters," Opt. Exp. 17,
9347-9356 (2009).

J. W. Nicholson, A. D. Yablon, J. M. Fini, M. D. Mermelstein,
"Measuring the modal content of large-mode-area- fibers ," IEEE J. Sel. Topics Quantum
Electron. 15, 61-70 (2009).

J. W. Nicholson, A. D. Yablon, S. Ramachandran, S. Ghalmi,
"Spatially and spectrally resolved imaging of modal content in large-mode-area fibers," Opt.
Exp. 16, 7233-7243 (2008).

Y. Kawahitoa, T. Terajimaa, H. Kimurab, T. Kurodaa, K. Nakataa,
S. Katayamaa, A. Inoueb, "High-power fiber laser welding and its application to metallic
glass Zr55Al10Ni5Cu30," Mat. Sci. Eng. B 148, 105-109 (2008).

S. Wielandy, "Implication of higher-order mode content is large
mode area fiber with good beam quality," Opt. Exp. 15, 15402-15409 (2007).

M. A. Golub, A. M. Prokhorov, I. N. Sisakian, V. A. Soifer,
"Synthesis of spatial filters for investigation of the transverse mode composition of
coherent radiation," Sov. J. Quantum Electron. 12 , 1208-1209 (1982 ).

W. H. Lee, "Sampled Fourier transform hologram generated by
computer ," Appl. Opt. 9, 639-643 (1970).

C. Schulze, A. Lorenz, D. Flamm, A. Hartung, S. Schröter, H.
Bartelt, M. Duparré, "Mode resolved bend loss in few-mode optical fibers," Opt. Exp. 21,
3170-3181 (2013).

J. Bromage, J. M. Fini, C. Dorrer, J. D. Zuegel,
"Characterization and optimization of Yb-doped photonic-crystal fiber rod amplifier using
spatially resolved spectral interferometry," App. Opt. 50, 2001-2007 (2011).

A. Dudley, I. A. Litvin, A. Forbes, "Quantitative measurement of
the orbital angular momentum density of light," Appl. Opt. 51, 823-833
(2012).

D. Flamm, C. Schulze, R. Brüning, O. A. Schmidt, T. Kaiser, S.
Schröter, M. Duparré, "Fast
$M^{2}$
measurement for fiber beams based on mode analysis," Appl. Opt. 51,
987-993 (2012).

S. Shwartz, M. Golub, S. Ruschin, "Diffractive optical elements
for mode-division multiplexing of temporal signals with the aid of Laguerre–Gaussian modes,"
Appl. Opt. 52, 2659-2669 (2013).

W. H. Lee, "Sampled Fourier transform hologram generated by
computer ," Appl. Opt. 9, 639-643 (1970).

Y. Z. Ma, Y. Sych, G. Onishchukov, S. Ramachandran, U. Peschel,
B. Schmauss, G. Leuchs, "Fiber-modes and fiber anisotropy characterization using
low-coherence interferometry," Appl. Phys. B 96, 345 -353 (2009).

H. J. Otto, F. Jansen, F. Stutzki, C. Jauregui, J. Limpert, A.
Tünnermann, "Improved modal reconstruction for spatially and spectrally resolved imaging,"
IEEE J. Lightw. Tech. 31, 1295-1299 (2013).

D. Flamm, C. Schulze, D. Naidoo, S. Schröter, A. Forbes, M.
Duparré, "All-digital tool for mode excitation and analysis in optical fibers," IEEE J.
Lightw. Tech. 31, 1023-1032 (2013).

P. Sprangle, A. Ting, J. Peñano, R. Fischer, B. Hafizi, "
Incoherent combining and atmospheric propagation of high-power fiber lasers for
directed-energy applications ," IEEE J. Quantum Electron. 45, 138-148
(2009).

J. W. Nicholson, A. D. Yablon, J. M. Fini, M. D. Mermelstein,
"Measuring the modal content of large-mode-area- fibers ," IEEE J. Sel. Topics Quantum
Electron. 15, 61-70 (2009).

D. J. Richardson, J. Nilsson, W. Clarkson, "High power fiber
lasers: Current status and future perspectives," J. Opt. Soc. Amer. B 27 , B63-B92 (2010
).

T. Bilici, S. Mutlu, H. Kalaycioqlu, A. Kurt, A. Sennaroqlu, M.
Gulsoy, "Development of a thulium (Tm:YAP) laser system for brain tissue ablation," Las.
Med. Sci. 26, 699-706 (2011).

Y. Kawahitoa, T. Terajimaa, H. Kimurab, T. Kurodaa, K. Nakataa,
S. Katayamaa, A. Inoueb, "High-power fiber laser welding and its application to metallic
glass Zr55Al10Ni5Cu30," Mat. Sci. Eng. B 148, 105-109 (2008).

C. Jauregui, J. Limpert, A. Tünnermann, "High power fibre lasers
," Nat. Photon. 7, 861-867 (2013).

C. Jauregui, T. Eidam, H.-J. Otto, F. Stutzki, F. Jansen, J.
Limpert, A. Tünnermann, "Temperature-induced index gratings and their impact on mode
instabilities in high-power fiber laser systems," Opt. Exp. 20, 440-451
(2012).

S. Wielandy, "Implication of higher-order mode content is large
mode area fiber with good beam quality," Opt. Exp. 15, 15402-15409 (2007).

J. W. Nicholson, A. D. Yablon, S. Ramachandran, S. Ghalmi,
"Spatially and spectrally resolved imaging of modal content in large-mode-area fibers," Opt.
Exp. 16, 7233-7243 (2008).

F. Kong, K. Saitoh, D. Mcclane, T. Hawkins, P. Foy, G. Gu, L.
Dong, "Mode area scaling with all-solid photonic bandgap fibers," Opt. Exp. 20, 26363-26372
(2012).

J. M. Fini, J. W. Nicholson, R. S. Windeler, E. M. Monberg, L.
Meng, B. Mangan, A. DeSantolo, F. V. DiMarcello, "Low-loss hollow-core fibers with improved
single-modedness," Opt. Exp. 21, 6233-6242 (2013).

J. Kerttula, V. Filippov, V. Ustimchik, Y. Chamorovskiy, O. G.
Okhotnikov, "Mode evolution in long tapered fibers with high tapering ratio," Opt. Exp. 20,
25461-25470 (2012).

J. F. Bauters, M. L. Davenport, M. J. R. Heck, J. K. Doylend, A.
Chen, A. W. Fang, J. E. Bowers, "Silicon on ultra-low-loss waveguide photonic integration
platform," Opt. Exp. 21, 544-555 (2013).

J. W. Nicholson, L. Meng, J. M. Fini, R. S. Windeler, A.
DeSantolo, E. Monberg, F. DiMarcello, Y. Dulashko, M. Hassan, R. Ortiz, "Measuring
higher-order modes in a low-loss, hollow-core, photonic-bandgap fiber ," Opt. Exp. 20,
20494-20505 (2012).

J. W. Nicholson, J. M. Fini, A. M. DeSantolo, X. Liu, K. Feder,
P. S. Westbrook, V. R. Supradeepa, E. Monberg, F. DiMarcello, R. Ortiz, C. Headley, D. J.
DiGiovanni, "Scaling the effective area of higher-order-mode erbium-doped fiber amplifiers,"
Opt. Exp. 20 , 24575-24584 ( 2012).

P. Kadwani, C. Jollivet, R. A. Sims, A. Schülzgen, L. Shah, M.
Richardson, "Comparison of higher-order mode suppression and Q-switched laser performances
in thulium-doped large mode area and photonic crystal fibers," Opt. Exp. 20, 24295-24303
(2012).

G. Gu, F. Kong, T. W. Hawkins, P. Foy, K. Wei, B. Samson, L.
Dong, "Impact of fiber outer boundaries on leaky mode losses in leakage channel fibers,"
Opt. Exp. 21, 24039-24048 (2013).

T. Kaiser, D. Flamm, S. Schröter, M. Duparré, "Complete modal
decomposition for optical fibers using CGH-based correlation filters," Opt. Exp. 17,
9347-9356 (2009).

D. N. Schimpf, R. A. Barankov, S. Ramachandran,
"Cross-correlated (C2) imaging of fiber and waveguide modes," Opt. Exp. 19, 13008-13019
(2011).

C. Schulze, D. Naidoo, D. Flamm, O. A. Schmidt, A. Forbes, M.
Duparré, "Wavefront reconstruction by modal decomposition," Opt. Exp. 20, 19714-19725
(2012).

D. Flamm, K.-C. Hou, P. Gelszinnis, C. Schulze, S. Schröter, M.
Duparré, "Modal characterization of fiber-to-fiber coupling processes," Opt. Lett. 38,
2128-2130 (2013).

F. Stutzki, H.-J. Otto, F. Jansen, C. Gaida, C. Jauregui, J.
Limpert, A. Tünnermann, "High-speed modal decomposition of mode instabilities in high-power
fiber lasers ," Opt. Lett. 36, 4572-4574 (2011).

D. Flamm, D. Naidoo, C. Schulze, A. Forbes, M. Duparré, "Mode
analysis with a spatial light modulator as a correlation filter," Opt. Lett. 37, 2478-2480
(2012).

D. Flamm, O. A. Schmidt, C. Schulze, J. Borchardt, T. Kaiser, S.
Schröter, M. Duparré, "Measuring the spatial polarization distribution of multimode beams
emerging from passive step-index large-mode-area fibers," Opt. Lett. 35, 3429-3431
(2010).

J. Jasapara, A. D. Yablon, "Spectrogram approach to
$S^{2}$
fiber mode analysis to distinguish between dispersion and distributed
scattering," Opt. Lett. 37, 3906-3908 (2012).

F. Stutzki, F. Jansen, T. Eidam, A. Steinmetz, C. Jauregui, J.
Limpert, A. Tünnermann, "High average power large-pitch fiber amplifier with robust
single-mode operation," Opt. Lett. 36, 689-691 (2011).

F. Stutzki, F. Jansen, A. Liem, C. Jauregui, J. Limpert, A.
Tünnermann, "26 mJ, 130 W Q-switched fiber-laser system with near-diffraction-limited beam
quality," Opt. Lett. 37, 1073-1075 (2012).

C. Schulze, O. A. Schmidt, D. Flamm, M. Duparré, S. Schröter,
"Modal analysis of beams emerging from a multi-core fiber using computer-generated holograms
," Proc. SPIE 7914, (2011, doi: 10.1117/12.874732 ).

M. A. Golub, A. M. Prokhorov, I. N. Sisakian, V. A. Soifer,
"Synthesis of spatial filters for investigation of the transverse mode composition of
coherent radiation," Sov. J. Quantum Electron. 12 , 1208-1209 (1982 ).