Abstract

We propose and demonstrate a facile approach for ultraviolet-visible broadband generation from a sapphire crystal core–borosilicate glass cladding hybrid fiber using a laser-heated pedestal growth technique. Considerable formation of F– and F2–type color emitters is effectively facilitated by Ti4+ ions and Al3+ vacancies, retaining efficient luminescence and high crystallinity of the sapphire core. These color centers intensify the ultraviolet, blue, and green emissions at 370, 450, and 540 nm, whereas the 650-nm red emission is contributed by Cr3+ in the octahedral sites of the corundum structure. Over 1-mW white light with an optical-to-optical efficiency of up to nearly 5% and 1931 Commission International de l’Eclairage chromaticity coordinate of (0.287, 0.333) is achieved under 325-nm excitation.

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2013 (2)

X. Liu, B. Chen, E. Y. B. Pun, and H. Lin, “White upconversion luminescence in Tm3+/Ho3+/Yb3+ triply doped K+–Na+ ion-exchanged aluminum germinate glass channel waveguide,” Opt. Mater. 35(3), 590–595 (2013).
[CrossRef]

H. X. Jiang and J. Y. Lin, “Nitride micro-LEDs and beyond – a decade progress review,” Opt. Express 21(S3), A475–A484 (2013).
[CrossRef]

2012 (6)

2011 (5)

2009 (3)

M. Itou, A. Fujiwara, and T. Uchino, “Reversible photoinduced interconversion of color centers in α-Al2O3 prepared under vacuum,” J. Phys. Chem. C 113(49), 20949–20957 (2009).
[CrossRef]

W. G. Telford, F. V. Subach, and V. V. Verkhusha, “Supercontinuum white light lasers for flow cytometry,” Cytometry A 75A(5), 450–459 (2009).
[CrossRef] [PubMed]

P. Blandin, S. Lévêque-Fort, S. Lécart, J. C. Cossec, M.-C. Potier, Z. Lenkei, F. Druon, and P. Georges, “Time-gated total internal reflection fluorescence microscopy with a supercontinuum excitation source,” Appl. Opt. 48(3), 553–559 (2009).
[CrossRef] [PubMed]

2008 (3)

2007 (2)

P. Boutinaud, P. Putaj, R. Mahiou, E. Cavalli, A. Speghini, and M. Bettinelli, “Quenching of lanthanide emission by intervalence charge transfer in crystals containing closed shell transition metal ions,” Spectrosc. Lett. 40(2), 209–220 (2007).
[CrossRef]

R. Ramírez, M. Tardío, R. González, J. E. Muñoz Santiuste, and M. R. Kokta, “Optical properties of vacancies in thermochemically reduced Mg-doped sapphire single crystals,” J. Appl. Phys. 101(12), 123520 (2007).
[CrossRef]

2005 (1)

R. Ramírez, M. Tardío, R. González, Y. Chen, and M. R. Kokta, “Photochromism of vacancy-related defects in thermochemically reduced α-Al2O3:Mg single crystals,” Appl. Phys. Lett. 86(8), 081914 (2005).
[CrossRef]

2004 (3)

R. M. Stroud, L. R. Nittler, and C. M. Alexander, “Polymorphism in presolar Al2O3 grains from asymptotic giant branch stars,” Science 305(5689), 1455–1457 (2004).
[CrossRef] [PubMed]

A. I. Surdo and V. S. Kortov, “Exciton mechanism of energy transfer to F–centers in dosimetric corundum crystals,” Radiat. Meas. 38(4-6), 667–671 (2004).
[CrossRef]

R. A. Leitgeb, W. Drexler, A. Unterhuber, B. Hermann, T. Bajraszewski, T. Le, A. Stingl, and A. F. Fercher, “Ultrahigh resolution Fourier domain optical coherence tomography,” Opt. Express 12(10), 2156–2165 (2004).
[CrossRef] [PubMed]

2003 (1)

J. G. Fujimoto, “Optical coherence tomography for ultrahigh resolution in vivo imaging,” Nat. Biotechnol. 21(11), 1361–1367 (2003).
[CrossRef] [PubMed]

2001 (1)

W. Drexler, U. Morgner, R. K. Ghanta, F. X. Kärtner, J. S. Schuman, and J. G. Fujimoto, “Ultrahigh-resolution ophthalmic optical coherence tomography,” Nat. Med. 7(4), 502–507 (2001).
[CrossRef] [PubMed]

1995 (3)

W. C. Wong, D. S. McClure, S. A. Basun, and M. R. Kokta, “Charge-exchange processes in titanium-doped sapphire crystals. I. Charge-exchange energies and titanium-bound excitons,” Phys. Rev. B Condens. Matter 51(9), 5682–5692 (1995).
[CrossRef] [PubMed]

W. C. Wong, D. S. McClure, S. A. Basun, and M. R. Kokta, “Charge-exchange processes in titanium-doped sapphire crystals. II. Charge-transfer transition states, carrier trapping, and detrapping,” Phys. Rev. B Condens. Matter 51(9), 5693–5698 (1995).
[CrossRef] [PubMed]

B. D. Evans, “A review of the optical properties of anion lattice vacancies, and electrical conduction in α-Al2O3: their relation to radiation-induced electrical degradation,” J. Nucl. Mater. 219, 202–223 (1995).
[CrossRef]

1994 (1)

M. Yamaga, T. Yosida, S. Hara, N. Kodama, and B. Henderson, “Optical and electron spin resonance spectroscopy of Ti3+ and Ti4+ in Al2O3,” J. Appl. Phys. 75(2), 1111–1117 (1994).
[CrossRef]

1993 (1)

K. J. Caulfield, R. Cooper, and J. F. Boas, “Luminescence from electron-irradiated sapphire,” Phys. Rev. B Condens. Matter 47(1), 55–61 (1993).
[CrossRef] [PubMed]

1992 (1)

B. Macalik, L. E. Bausá, J. García-Solé, F. Jaque, J. E. Muñoz Santiuste, and I. Vergara, “Blue emission in Ti-sapphire laser crystal,” Appl. Phys. B 55, 144–147 (1992).

1991 (1)

D. Huang, E. A. Swanson, C. P. Lin, J. S. Schuman, W. G. Stinson, W. Chang, M. R. Hee, T. Flotte, K. Gregory, C. A. Puliafito, and J. G. Fujimoto, “Optical coherence tomography,” Science 254(5035), 1178–1181 (1991).
[CrossRef] [PubMed]

1988 (1)

A. Sanchez, A. J. Strauss, R. L. Aggarwal, and R. E. Fahey, “Crystal growth, spectroscopy, and laser characteristics of Ti:Al2O3,” IEEE J. Quantum Electron. 24(6), 995–1002 (1988).
[CrossRef]

1986 (1)

1984 (1)

M. G. Springils and J. A. Valbis, “Visible luminescence of colour centres in sapphire,” Phys. Status Solidi, B Basic Res. 123(1), 335–343 (1984).
[CrossRef]

1980 (1)

B. Jeffries, G. P. Summers, and J. H. Crawford, “F–center fluorescence in neutron–bombarded sapphire,” J. Appl. Phys. 51(7), 3984–3986 (1980).
[CrossRef]

1979 (1)

M. D. Rechtin, “A transmission electron microscopy study of the defect microstructure of Al2O3, subjected to ion bombardment,” Radiat. Eff. 42(3-4), 129–144 (1979).
[CrossRef]

1978 (2)

K. H. Lee and J. H. Crawford, “Additive coloration of sapphire,” Appl. Phys. Lett. 33(4), 273–275 (1978).
[CrossRef]

B. D. Evans and M. Stapelbroek, “Optical properties of the F+ center in crystalline Al2O3,” Phys. Rev. B 18(12), 7089–7098 (1978).
[CrossRef]

1975 (1)

P. D. Townsend, “Colour centres past, present and future,” Nature 258(5533), 293–296 (1975).
[CrossRef]

1968 (1)

P. Görlich, H. Karras, G. Kötitz, and R. Rauch, “Phonon-assisted colour centre fluorescence of additively coloured alkali earth fluoride crystals,” Phys. Status Solidi, B Basic Res. 25(1), K15–K18 (1968).
[CrossRef]

1963 (1)

D. B. Fitchen, R. H. Silsbee, T. A. Fulton, and E. L. Wolf, “Zero-phonon transitions of color centers in alkali halides,” Phys. Rev. Lett. 11(6), 275–277 (1963).
[CrossRef]

Abrate, S.

Aggarwal, R. L.

A. Sanchez, A. J. Strauss, R. L. Aggarwal, and R. E. Fahey, “Crystal growth, spectroscopy, and laser characteristics of Ti:Al2O3,” IEEE J. Quantum Electron. 24(6), 995–1002 (1988).
[CrossRef]

Alexander, C. M.

R. M. Stroud, L. R. Nittler, and C. M. Alexander, “Polymorphism in presolar Al2O3 grains from asymptotic giant branch stars,” Science 305(5689), 1455–1457 (2004).
[CrossRef] [PubMed]

An, L.

Backus, S.

Bajraszewski, T.

Balcer, L. J.

E. M. Frohman, J. G. Fujimoto, T. C. Frohman, P. A. Calabresi, G. Cutter, and L. J. Balcer, “Optical coherence tomography: a window into the mechanisms of multiple sclerosis,” Nat. Clin. Pract. Neurol. 4(12), 664–675 (2008).
[CrossRef] [PubMed]

Basun, S. A.

W. C. Wong, D. S. McClure, S. A. Basun, and M. R. Kokta, “Charge-exchange processes in titanium-doped sapphire crystals. II. Charge-transfer transition states, carrier trapping, and detrapping,” Phys. Rev. B Condens. Matter 51(9), 5693–5698 (1995).
[CrossRef] [PubMed]

W. C. Wong, D. S. McClure, S. A. Basun, and M. R. Kokta, “Charge-exchange processes in titanium-doped sapphire crystals. I. Charge-exchange energies and titanium-bound excitons,” Phys. Rev. B Condens. Matter 51(9), 5682–5692 (1995).
[CrossRef] [PubMed]

Bausá, L. E.

B. Macalik, L. E. Bausá, J. García-Solé, F. Jaque, J. E. Muñoz Santiuste, and I. Vergara, “Blue emission in Ti-sapphire laser crystal,” Appl. Phys. B 55, 144–147 (1992).

Bettinelli, M.

P. Boutinaud, P. Putaj, R. Mahiou, E. Cavalli, A. Speghini, and M. Bettinelli, “Quenching of lanthanide emission by intervalence charge transfer in crystals containing closed shell transition metal ions,” Spectrosc. Lett. 40(2), 209–220 (2007).
[CrossRef]

Blandin, P.

Boas, J. F.

K. J. Caulfield, R. Cooper, and J. F. Boas, “Luminescence from electron-irradiated sapphire,” Phys. Rev. B Condens. Matter 47(1), 55–61 (1993).
[CrossRef] [PubMed]

Boetti, N. G.

Boutinaud, P.

P. Boutinaud, P. Putaj, R. Mahiou, E. Cavalli, A. Speghini, and M. Bettinelli, “Quenching of lanthanide emission by intervalence charge transfer in crystals containing closed shell transition metal ions,” Spectrosc. Lett. 40(2), 209–220 (2007).
[CrossRef]

Calabresi, P. A.

E. M. Frohman, J. G. Fujimoto, T. C. Frohman, P. A. Calabresi, G. Cutter, and L. J. Balcer, “Optical coherence tomography: a window into the mechanisms of multiple sclerosis,” Nat. Clin. Pract. Neurol. 4(12), 664–675 (2008).
[CrossRef] [PubMed]

Caulfield, K. J.

K. J. Caulfield, R. Cooper, and J. F. Boas, “Luminescence from electron-irradiated sapphire,” Phys. Rev. B Condens. Matter 47(1), 55–61 (1993).
[CrossRef] [PubMed]

Cavalli, E.

P. Boutinaud, P. Putaj, R. Mahiou, E. Cavalli, A. Speghini, and M. Bettinelli, “Quenching of lanthanide emission by intervalence charge transfer in crystals containing closed shell transition metal ions,” Spectrosc. Lett. 40(2), 209–220 (2007).
[CrossRef]

Chang, C. K.

Chang, W.

D. Huang, E. A. Swanson, C. P. Lin, J. S. Schuman, W. G. Stinson, W. Chang, M. R. Hee, T. Flotte, K. Gregory, C. A. Puliafito, and J. G. Fujimoto, “Optical coherence tomography,” Science 254(5035), 1178–1181 (1991).
[CrossRef] [PubMed]

Chen, B.

X. Liu, B. Chen, E. Y. B. Pun, and H. Lin, “White upconversion luminescence in Tm3+/Ho3+/Yb3+ triply doped K+–Na+ ion-exchanged aluminum germinate glass channel waveguide,” Opt. Mater. 35(3), 590–595 (2013).
[CrossRef]

Chen, M. Y.

Chen, T. H.

C. C. Lai, S. C. Wang, Y. S. Lin, T. H. Chen, and S. L. Huang, “Near-field spectroscopy of broadband emissions from γ-Al2O3 nanocrystals in Cr-doped double-clad fibers,” J. Phys. Chem. C 115(41), 20289–20294 (2011).
[CrossRef]

Chen, Y.

R. Ramírez, M. Tardío, R. González, Y. Chen, and M. R. Kokta, “Photochromism of vacancy-related defects in thermochemically reduced α-Al2O3:Mg single crystals,” Appl. Phys. Lett. 86(8), 081914 (2005).
[CrossRef]

Cheng, N. C.

Cooper, R.

K. J. Caulfield, R. Cooper, and J. F. Boas, “Luminescence from electron-irradiated sapphire,” Phys. Rev. B Condens. Matter 47(1), 55–61 (1993).
[CrossRef] [PubMed]

Cossec, J. C.

Crawford, J. H.

B. Jeffries, G. P. Summers, and J. H. Crawford, “F–center fluorescence in neutron–bombarded sapphire,” J. Appl. Phys. 51(7), 3984–3986 (1980).
[CrossRef]

K. H. Lee and J. H. Crawford, “Additive coloration of sapphire,” Appl. Phys. Lett. 33(4), 273–275 (1978).
[CrossRef]

Cutter, G.

E. M. Frohman, J. G. Fujimoto, T. C. Frohman, P. A. Calabresi, G. Cutter, and L. J. Balcer, “Optical coherence tomography: a window into the mechanisms of multiple sclerosis,” Nat. Clin. Pract. Neurol. 4(12), 664–675 (2008).
[CrossRef] [PubMed]

de Matos, C. J. S.

de Oliveira, R. E. P.

Drexler, W.

R. A. Leitgeb, W. Drexler, A. Unterhuber, B. Hermann, T. Bajraszewski, T. Le, A. Stingl, and A. F. Fercher, “Ultrahigh resolution Fourier domain optical coherence tomography,” Opt. Express 12(10), 2156–2165 (2004).
[CrossRef] [PubMed]

W. Drexler, U. Morgner, R. K. Ghanta, F. X. Kärtner, J. S. Schuman, and J. G. Fujimoto, “Ultrahigh-resolution ophthalmic optical coherence tomography,” Nat. Med. 7(4), 502–507 (2001).
[CrossRef] [PubMed]

Druon, F.

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C. C. Lai, P. Yeh, S. C. Wang, D. Y. Jheng, C. N. Tsai, and S. L. Huang, “Strain-dependent fluorescence spectroscopy of nanocrystals and nanoclusters in Cr:YAG crystalline-core fibers and its impact on lasing behaviors,” J. Phys. Chem. C 116(49), 26052–26059 (2012).
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R. Ramírez, M. Tardío, R. González, Y. Chen, and M. R. Kokta, “Photochromism of vacancy-related defects in thermochemically reduced α-Al2O3:Mg single crystals,” Appl. Phys. Lett. 86(8), 081914 (2005).
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Lai, C. C.

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N. C. Cheng, T. H. Hsieh, Y. T. Wang, C. C. Lai, C. K. Chang, M. Y. Lin, D. W. Huang, J. W. Tjiu, and S. L. Huang, “Cell death detection by quantitative three-dimensional single-cell tomography,” Biomed. Opt. Express 3(9), 2111–2120 (2012).
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C. C. Lai, C. P. Ke, S. K. Liu, D. Y. Jheng, D. J. Wang, M. Y. Chen, Y. S. Li, P. S. Yeh, and S. L. Huang, “Efficient and low-threshold Cr4+:YAG double-clad crystal fiber laser,” Opt. Lett. 36(6), 784–786 (2011).
[CrossRef] [PubMed]

C. C. Lai, S. C. Wang, Y. S. Lin, T. H. Chen, and S. L. Huang, “Near-field spectroscopy of broadband emissions from γ-Al2O3 nanocrystals in Cr-doped double-clad fibers,” J. Phys. Chem. C 115(41), 20289–20294 (2011).
[CrossRef]

C. C. Lai, H. J. Tsai, K. Y. Huang, K. Y. Hsu, Z. W. Lin, K. D. Ji, W. J. Zhuo, and S. L. Huang, “Cr4+:YAG double-clad crystal fiber laser,” Opt. Lett. 33(24), 2919–2921 (2008).
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Lin, M. Y.

Lin, S. R.

C. C. Lai, C. P. Ke, S. K. Liu, C. Y. Lo, D. Y. Jheng, S. C. Wang, S. R. Lin, P. S. Yeh, and S. L. Huang, “Intracavity and resonant Raman crystal fiber laser,” Appl. Phys. Lett. 100(26), 261101 (2012).
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C. C. Lai, S. C. Wang, Y. S. Lin, T. H. Chen, and S. L. Huang, “Near-field spectroscopy of broadband emissions from γ-Al2O3 nanocrystals in Cr-doped double-clad fibers,” J. Phys. Chem. C 115(41), 20289–20294 (2011).
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Liu, S. K.

C. C. Lai, C. P. Ke, S. K. Liu, C. Y. Lo, D. Y. Jheng, S. C. Wang, S. R. Lin, P. S. Yeh, and S. L. Huang, “Intracavity and resonant Raman crystal fiber laser,” Appl. Phys. Lett. 100(26), 261101 (2012).
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C. C. Lai, C. P. Ke, S. K. Liu, D. Y. Jheng, D. J. Wang, M. Y. Chen, Y. S. Li, P. S. Yeh, and S. L. Huang, “Efficient and low-threshold Cr4+:YAG double-clad crystal fiber laser,” Opt. Lett. 36(6), 784–786 (2011).
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X. Liu, B. Chen, E. Y. B. Pun, and H. Lin, “White upconversion luminescence in Tm3+/Ho3+/Yb3+ triply doped K+–Na+ ion-exchanged aluminum germinate glass channel waveguide,” Opt. Mater. 35(3), 590–595 (2013).
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C. C. Lai, C. P. Ke, S. K. Liu, C. Y. Lo, D. Y. Jheng, S. C. Wang, S. R. Lin, P. S. Yeh, and S. L. Huang, “Intracavity and resonant Raman crystal fiber laser,” Appl. Phys. Lett. 100(26), 261101 (2012).
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Mahiou, R.

P. Boutinaud, P. Putaj, R. Mahiou, E. Cavalli, A. Speghini, and M. Bettinelli, “Quenching of lanthanide emission by intervalence charge transfer in crystals containing closed shell transition metal ions,” Spectrosc. Lett. 40(2), 209–220 (2007).
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W. C. Wong, D. S. McClure, S. A. Basun, and M. R. Kokta, “Charge-exchange processes in titanium-doped sapphire crystals. II. Charge-transfer transition states, carrier trapping, and detrapping,” Phys. Rev. B Condens. Matter 51(9), 5693–5698 (1995).
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Milanese, D.

Morgner, U.

W. Drexler, U. Morgner, R. K. Ghanta, F. X. Kärtner, J. S. Schuman, and J. G. Fujimoto, “Ultrahigh-resolution ophthalmic optical coherence tomography,” Nat. Med. 7(4), 502–507 (2001).
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Muñoz Santiuste, J. E.

R. Ramírez, M. Tardío, R. González, J. E. Muñoz Santiuste, and M. R. Kokta, “Optical properties of vacancies in thermochemically reduced Mg-doped sapphire single crystals,” J. Appl. Phys. 101(12), 123520 (2007).
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B. Macalik, L. E. Bausá, J. García-Solé, F. Jaque, J. E. Muñoz Santiuste, and I. Vergara, “Blue emission in Ti-sapphire laser crystal,” Appl. Phys. B 55, 144–147 (1992).

Mura, E.

Murnane, M.

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Nittler, L. R.

R. M. Stroud, L. R. Nittler, and C. M. Alexander, “Polymorphism in presolar Al2O3 grains from asymptotic giant branch stars,” Science 305(5689), 1455–1457 (2004).
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D. Huang, E. A. Swanson, C. P. Lin, J. S. Schuman, W. G. Stinson, W. Chang, M. R. Hee, T. Flotte, K. Gregory, C. A. Puliafito, and J. G. Fujimoto, “Optical coherence tomography,” Science 254(5035), 1178–1181 (1991).
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X. Liu, B. Chen, E. Y. B. Pun, and H. Lin, “White upconversion luminescence in Tm3+/Ho3+/Yb3+ triply doped K+–Na+ ion-exchanged aluminum germinate glass channel waveguide,” Opt. Mater. 35(3), 590–595 (2013).
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P. Boutinaud, P. Putaj, R. Mahiou, E. Cavalli, A. Speghini, and M. Bettinelli, “Quenching of lanthanide emission by intervalence charge transfer in crystals containing closed shell transition metal ions,” Spectrosc. Lett. 40(2), 209–220 (2007).
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R. Ramírez, M. Tardío, R. González, J. E. Muñoz Santiuste, and M. R. Kokta, “Optical properties of vacancies in thermochemically reduced Mg-doped sapphire single crystals,” J. Appl. Phys. 101(12), 123520 (2007).
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R. Ramírez, M. Tardío, R. González, Y. Chen, and M. R. Kokta, “Photochromism of vacancy-related defects in thermochemically reduced α-Al2O3:Mg single crystals,” Appl. Phys. Lett. 86(8), 081914 (2005).
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P. Görlich, H. Karras, G. Kötitz, and R. Rauch, “Phonon-assisted colour centre fluorescence of additively coloured alkali earth fluoride crystals,” Phys. Status Solidi, B Basic Res. 25(1), K15–K18 (1968).
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Schuman, J. S.

W. Drexler, U. Morgner, R. K. Ghanta, F. X. Kärtner, J. S. Schuman, and J. G. Fujimoto, “Ultrahigh-resolution ophthalmic optical coherence tomography,” Nat. Med. 7(4), 502–507 (2001).
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D. Huang, E. A. Swanson, C. P. Lin, J. S. Schuman, W. G. Stinson, W. Chang, M. R. Hee, T. Flotte, K. Gregory, C. A. Puliafito, and J. G. Fujimoto, “Optical coherence tomography,” Science 254(5035), 1178–1181 (1991).
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Silsbee, R. H.

D. B. Fitchen, R. H. Silsbee, T. A. Fulton, and E. L. Wolf, “Zero-phonon transitions of color centers in alkali halides,” Phys. Rev. Lett. 11(6), 275–277 (1963).
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Speghini, A.

P. Boutinaud, P. Putaj, R. Mahiou, E. Cavalli, A. Speghini, and M. Bettinelli, “Quenching of lanthanide emission by intervalence charge transfer in crystals containing closed shell transition metal ions,” Spectrosc. Lett. 40(2), 209–220 (2007).
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D. Huang, E. A. Swanson, C. P. Lin, J. S. Schuman, W. G. Stinson, W. Chang, M. R. Hee, T. Flotte, K. Gregory, C. A. Puliafito, and J. G. Fujimoto, “Optical coherence tomography,” Science 254(5035), 1178–1181 (1991).
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A. Sanchez, A. J. Strauss, R. L. Aggarwal, and R. E. Fahey, “Crystal growth, spectroscopy, and laser characteristics of Ti:Al2O3,” IEEE J. Quantum Electron. 24(6), 995–1002 (1988).
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R. M. Stroud, L. R. Nittler, and C. M. Alexander, “Polymorphism in presolar Al2O3 grains from asymptotic giant branch stars,” Science 305(5689), 1455–1457 (2004).
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W. G. Telford, F. V. Subach, and V. V. Verkhusha, “Supercontinuum white light lasers for flow cytometry,” Cytometry A 75A(5), 450–459 (2009).
[CrossRef] [PubMed]

Summers, G. P.

B. Jeffries, G. P. Summers, and J. H. Crawford, “F–center fluorescence in neutron–bombarded sapphire,” J. Appl. Phys. 51(7), 3984–3986 (1980).
[CrossRef]

Surdo, A. I.

A. I. Surdo and V. S. Kortov, “Exciton mechanism of energy transfer to F–centers in dosimetric corundum crystals,” Radiat. Meas. 38(4-6), 667–671 (2004).
[CrossRef]

Swanson, E. A.

D. Huang, E. A. Swanson, C. P. Lin, J. S. Schuman, W. G. Stinson, W. Chang, M. R. Hee, T. Flotte, K. Gregory, C. A. Puliafito, and J. G. Fujimoto, “Optical coherence tomography,” Science 254(5035), 1178–1181 (1991).
[CrossRef] [PubMed]

Taft, G.

Tardío, M.

R. Ramírez, M. Tardío, R. González, J. E. Muñoz Santiuste, and M. R. Kokta, “Optical properties of vacancies in thermochemically reduced Mg-doped sapphire single crystals,” J. Appl. Phys. 101(12), 123520 (2007).
[CrossRef]

R. Ramírez, M. Tardío, R. González, Y. Chen, and M. R. Kokta, “Photochromism of vacancy-related defects in thermochemically reduced α-Al2O3:Mg single crystals,” Appl. Phys. Lett. 86(8), 081914 (2005).
[CrossRef]

Telford, W. G.

W. G. Telford, F. V. Subach, and V. V. Verkhusha, “Supercontinuum white light lasers for flow cytometry,” Cytometry A 75A(5), 450–459 (2009).
[CrossRef] [PubMed]

Tjiu, J. W.

Townsend, P. D.

P. D. Townsend, “Colour centres past, present and future,” Nature 258(5533), 293–296 (1975).
[CrossRef]

Tsai, C. N.

C. C. Lai, P. Yeh, S. C. Wang, D. Y. Jheng, C. N. Tsai, and S. L. Huang, “Strain-dependent fluorescence spectroscopy of nanocrystals and nanoclusters in Cr:YAG crystalline-core fibers and its impact on lasing behaviors,” J. Phys. Chem. C 116(49), 26052–26059 (2012).
[CrossRef]

Tsai, H. J.

Uchino, T.

M. Itou, A. Fujiwara, and T. Uchino, “Reversible photoinduced interconversion of color centers in α-Al2O3 prepared under vacuum,” J. Phys. Chem. C 113(49), 20949–20957 (2009).
[CrossRef]

Unterhuber, A.

Valbis, J. A.

M. G. Springils and J. A. Valbis, “Visible luminescence of colour centres in sapphire,” Phys. Status Solidi, B Basic Res. 123(1), 335–343 (1984).
[CrossRef]

Vergara, I.

B. Macalik, L. E. Bausá, J. García-Solé, F. Jaque, J. E. Muñoz Santiuste, and I. Vergara, “Blue emission in Ti-sapphire laser crystal,” Appl. Phys. B 55, 144–147 (1992).

Verkhusha, V. V.

W. G. Telford, F. V. Subach, and V. V. Verkhusha, “Supercontinuum white light lasers for flow cytometry,” Cytometry A 75A(5), 450–459 (2009).
[CrossRef] [PubMed]

Wang, D. J.

Wang, R. K.

Wang, S. C.

C. C. Lai, P. Yeh, S. C. Wang, D. Y. Jheng, C. N. Tsai, and S. L. Huang, “Strain-dependent fluorescence spectroscopy of nanocrystals and nanoclusters in Cr:YAG crystalline-core fibers and its impact on lasing behaviors,” J. Phys. Chem. C 116(49), 26052–26059 (2012).
[CrossRef]

C. C. Lai, C. P. Ke, S. K. Liu, C. Y. Lo, D. Y. Jheng, S. C. Wang, S. R. Lin, P. S. Yeh, and S. L. Huang, “Intracavity and resonant Raman crystal fiber laser,” Appl. Phys. Lett. 100(26), 261101 (2012).
[CrossRef]

C. C. Lai, S. C. Wang, Y. S. Lin, T. H. Chen, and S. L. Huang, “Near-field spectroscopy of broadband emissions from γ-Al2O3 nanocrystals in Cr-doped double-clad fibers,” J. Phys. Chem. C 115(41), 20289–20294 (2011).
[CrossRef]

Wang, Y. T.

Wolf, E. L.

D. B. Fitchen, R. H. Silsbee, T. A. Fulton, and E. L. Wolf, “Zero-phonon transitions of color centers in alkali halides,” Phys. Rev. Lett. 11(6), 275–277 (1963).
[CrossRef]

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W. C. Wong, D. S. McClure, S. A. Basun, and M. R. Kokta, “Charge-exchange processes in titanium-doped sapphire crystals. I. Charge-exchange energies and titanium-bound excitons,” Phys. Rev. B Condens. Matter 51(9), 5682–5692 (1995).
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W. C. Wong, D. S. McClure, S. A. Basun, and M. R. Kokta, “Charge-exchange processes in titanium-doped sapphire crystals. II. Charge-transfer transition states, carrier trapping, and detrapping,” Phys. Rev. B Condens. Matter 51(9), 5693–5698 (1995).
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M. Yamaga, T. Yosida, S. Hara, N. Kodama, and B. Henderson, “Optical and electron spin resonance spectroscopy of Ti3+ and Ti4+ in Al2O3,” J. Appl. Phys. 75(2), 1111–1117 (1994).
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C. C. Lai, P. Yeh, S. C. Wang, D. Y. Jheng, C. N. Tsai, and S. L. Huang, “Strain-dependent fluorescence spectroscopy of nanocrystals and nanoclusters in Cr:YAG crystalline-core fibers and its impact on lasing behaviors,” J. Phys. Chem. C 116(49), 26052–26059 (2012).
[CrossRef]

Yeh, P. S.

C. C. Lai, C. P. Ke, S. K. Liu, C. Y. Lo, D. Y. Jheng, S. C. Wang, S. R. Lin, P. S. Yeh, and S. L. Huang, “Intracavity and resonant Raman crystal fiber laser,” Appl. Phys. Lett. 100(26), 261101 (2012).
[CrossRef]

C. C. Lai, C. P. Ke, S. K. Liu, D. Y. Jheng, D. J. Wang, M. Y. Chen, Y. S. Li, P. S. Yeh, and S. L. Huang, “Efficient and low-threshold Cr4+:YAG double-clad crystal fiber laser,” Opt. Lett. 36(6), 784–786 (2011).
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M. Yamaga, T. Yosida, S. Hara, N. Kodama, and B. Henderson, “Optical and electron spin resonance spectroscopy of Ti3+ and Ti4+ in Al2O3,” J. Appl. Phys. 75(2), 1111–1117 (1994).
[CrossRef]

Yu, J. S.

Zhi, Z.

Zhu, W.

W. Zhu and G. Pezzotti, “Phonon deformation potentials for the corundum structure of sapphire,” J. Raman. Spectrosc. 42(11), 2015–2025 (2011).
[CrossRef]

Zhuo, W. J.

Appl. Opt. (1)

Appl. Phys. B (1)

B. Macalik, L. E. Bausá, J. García-Solé, F. Jaque, J. E. Muñoz Santiuste, and I. Vergara, “Blue emission in Ti-sapphire laser crystal,” Appl. Phys. B 55, 144–147 (1992).

Appl. Phys. Lett. (3)

K. H. Lee and J. H. Crawford, “Additive coloration of sapphire,” Appl. Phys. Lett. 33(4), 273–275 (1978).
[CrossRef]

R. Ramírez, M. Tardío, R. González, Y. Chen, and M. R. Kokta, “Photochromism of vacancy-related defects in thermochemically reduced α-Al2O3:Mg single crystals,” Appl. Phys. Lett. 86(8), 081914 (2005).
[CrossRef]

C. C. Lai, C. P. Ke, S. K. Liu, C. Y. Lo, D. Y. Jheng, S. C. Wang, S. R. Lin, P. S. Yeh, and S. L. Huang, “Intracavity and resonant Raman crystal fiber laser,” Appl. Phys. Lett. 100(26), 261101 (2012).
[CrossRef]

Biomed. Opt. Express (1)

Cytometry A (1)

W. G. Telford, F. V. Subach, and V. V. Verkhusha, “Supercontinuum white light lasers for flow cytometry,” Cytometry A 75A(5), 450–459 (2009).
[CrossRef] [PubMed]

IEEE J. Quantum Electron. (1)

A. Sanchez, A. J. Strauss, R. L. Aggarwal, and R. E. Fahey, “Crystal growth, spectroscopy, and laser characteristics of Ti:Al2O3,” IEEE J. Quantum Electron. 24(6), 995–1002 (1988).
[CrossRef]

J. Appl. Phys. (3)

M. Yamaga, T. Yosida, S. Hara, N. Kodama, and B. Henderson, “Optical and electron spin resonance spectroscopy of Ti3+ and Ti4+ in Al2O3,” J. Appl. Phys. 75(2), 1111–1117 (1994).
[CrossRef]

B. Jeffries, G. P. Summers, and J. H. Crawford, “F–center fluorescence in neutron–bombarded sapphire,” J. Appl. Phys. 51(7), 3984–3986 (1980).
[CrossRef]

R. Ramírez, M. Tardío, R. González, J. E. Muñoz Santiuste, and M. R. Kokta, “Optical properties of vacancies in thermochemically reduced Mg-doped sapphire single crystals,” J. Appl. Phys. 101(12), 123520 (2007).
[CrossRef]

J. Lightwave Technol. (1)

J. Nucl. Mater. (1)

B. D. Evans, “A review of the optical properties of anion lattice vacancies, and electrical conduction in α-Al2O3: their relation to radiation-induced electrical degradation,” J. Nucl. Mater. 219, 202–223 (1995).
[CrossRef]

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

J. Phys. Chem. C (3)

C. C. Lai, S. C. Wang, Y. S. Lin, T. H. Chen, and S. L. Huang, “Near-field spectroscopy of broadband emissions from γ-Al2O3 nanocrystals in Cr-doped double-clad fibers,” J. Phys. Chem. C 115(41), 20289–20294 (2011).
[CrossRef]

M. Itou, A. Fujiwara, and T. Uchino, “Reversible photoinduced interconversion of color centers in α-Al2O3 prepared under vacuum,” J. Phys. Chem. C 113(49), 20949–20957 (2009).
[CrossRef]

C. C. Lai, P. Yeh, S. C. Wang, D. Y. Jheng, C. N. Tsai, and S. L. Huang, “Strain-dependent fluorescence spectroscopy of nanocrystals and nanoclusters in Cr:YAG crystalline-core fibers and its impact on lasing behaviors,” J. Phys. Chem. C 116(49), 26052–26059 (2012).
[CrossRef]

J. Raman. Spectrosc. (1)

W. Zhu and G. Pezzotti, “Phonon deformation potentials for the corundum structure of sapphire,” J. Raman. Spectrosc. 42(11), 2015–2025 (2011).
[CrossRef]

Nat. Biotechnol. (1)

J. G. Fujimoto, “Optical coherence tomography for ultrahigh resolution in vivo imaging,” Nat. Biotechnol. 21(11), 1361–1367 (2003).
[CrossRef] [PubMed]

Nat. Clin. Pract. Neurol. (1)

E. M. Frohman, J. G. Fujimoto, T. C. Frohman, P. A. Calabresi, G. Cutter, and L. J. Balcer, “Optical coherence tomography: a window into the mechanisms of multiple sclerosis,” Nat. Clin. Pract. Neurol. 4(12), 664–675 (2008).
[CrossRef] [PubMed]

Nat. Med. (1)

W. Drexler, U. Morgner, R. K. Ghanta, F. X. Kärtner, J. S. Schuman, and J. G. Fujimoto, “Ultrahigh-resolution ophthalmic optical coherence tomography,” Nat. Med. 7(4), 502–507 (2001).
[CrossRef] [PubMed]

Nature (1)

P. D. Townsend, “Colour centres past, present and future,” Nature 258(5533), 293–296 (1975).
[CrossRef]

Opt. Express (5)

Opt. Lett. (3)

Opt. Mater. (1)

X. Liu, B. Chen, E. Y. B. Pun, and H. Lin, “White upconversion luminescence in Tm3+/Ho3+/Yb3+ triply doped K+–Na+ ion-exchanged aluminum germinate glass channel waveguide,” Opt. Mater. 35(3), 590–595 (2013).
[CrossRef]

Opt. Mater. Express (1)

Phys. Rev. B (1)

B. D. Evans and M. Stapelbroek, “Optical properties of the F+ center in crystalline Al2O3,” Phys. Rev. B 18(12), 7089–7098 (1978).
[CrossRef]

Phys. Rev. B Condens. Matter (3)

K. J. Caulfield, R. Cooper, and J. F. Boas, “Luminescence from electron-irradiated sapphire,” Phys. Rev. B Condens. Matter 47(1), 55–61 (1993).
[CrossRef] [PubMed]

W. C. Wong, D. S. McClure, S. A. Basun, and M. R. Kokta, “Charge-exchange processes in titanium-doped sapphire crystals. I. Charge-exchange energies and titanium-bound excitons,” Phys. Rev. B Condens. Matter 51(9), 5682–5692 (1995).
[CrossRef] [PubMed]

W. C. Wong, D. S. McClure, S. A. Basun, and M. R. Kokta, “Charge-exchange processes in titanium-doped sapphire crystals. II. Charge-transfer transition states, carrier trapping, and detrapping,” Phys. Rev. B Condens. Matter 51(9), 5693–5698 (1995).
[CrossRef] [PubMed]

Phys. Rev. Lett. (1)

D. B. Fitchen, R. H. Silsbee, T. A. Fulton, and E. L. Wolf, “Zero-phonon transitions of color centers in alkali halides,” Phys. Rev. Lett. 11(6), 275–277 (1963).
[CrossRef]

Phys. Status Solidi, B Basic Res. (2)

P. Görlich, H. Karras, G. Kötitz, and R. Rauch, “Phonon-assisted colour centre fluorescence of additively coloured alkali earth fluoride crystals,” Phys. Status Solidi, B Basic Res. 25(1), K15–K18 (1968).
[CrossRef]

M. G. Springils and J. A. Valbis, “Visible luminescence of colour centres in sapphire,” Phys. Status Solidi, B Basic Res. 123(1), 335–343 (1984).
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Radiat. Eff. (1)

M. D. Rechtin, “A transmission electron microscopy study of the defect microstructure of Al2O3, subjected to ion bombardment,” Radiat. Eff. 42(3-4), 129–144 (1979).
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Radiat. Meas. (1)

A. I. Surdo and V. S. Kortov, “Exciton mechanism of energy transfer to F–centers in dosimetric corundum crystals,” Radiat. Meas. 38(4-6), 667–671 (2004).
[CrossRef]

Science (2)

R. M. Stroud, L. R. Nittler, and C. M. Alexander, “Polymorphism in presolar Al2O3 grains from asymptotic giant branch stars,” Science 305(5689), 1455–1457 (2004).
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D. Huang, E. A. Swanson, C. P. Lin, J. S. Schuman, W. G. Stinson, W. Chang, M. R. Hee, T. Flotte, K. Gregory, C. A. Puliafito, and J. G. Fujimoto, “Optical coherence tomography,” Science 254(5035), 1178–1181 (1991).
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B. Henderson, Defects in Crystalline Solids (Arnold, London, 1972).

T. T. Basiev, P. G. Zverev, and S. B. Mirov, Color Center Lasers, Handbook of Laser Technology and Applications (Institute of Physics Publishing, Bristol, 2003).

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C. Zeiss, http://meditec.zeiss.com

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Thorlabs, http://www.thorlabs.com

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Figures (8)

Fig. 1
Fig. 1

Schematic of growth of sapphire crystalline-core fiber.

Fig. 2
Fig. 2

Schematic of room-temperature white light measurement. FL, focusing lens.

Fig. 3
Fig. 3

(a) End face image of a sapphire crystal core–borosilicate glass cladding hybrid fiber. (b) Magnified SEM image of the 40-μm-diameter sapphire core. (c) Schematic of the sapphire structure viewed along the c axis. Large white, small blue, and small dashed circles represent O, Al atoms, and octahedral hollows between the closely packed O2- ions, respectively. (d),(e) EDX mappings of Al and Si, showing the closest hexagonal packing, as depicted in (c). (f) EDX spectrum of the sapphire core. (e),(f) HR-TEM images of the core-clad interface, showing high crystallinity as evidenced by the sharp SAED spots in the inset.

Fig. 4
Fig. 4

325-nm-excited (a) PL and (b) Raman spectra of the starting material (gray), 40-μm sapphire core (blue, refer to step 1 in Fig. 1), and 40-μm sapphire core with borosilicate glass cladding (red, refer to step 2 in Fig. 1).

Fig. 5
Fig. 5

Color evolutions during growth of sapphire crystalline-core fibers.

Fig. 6
Fig. 6

Greenish broadband spectrum from 40-μm sapphire crystalline core showing a considerable amount of F22+ centers (577 nm) and aggregated V Al with Ti4+ ions (485 nm), respectively.

Fig. 7
Fig. 7

UV-VIS broadband white light generation from 40-μm sapphire crystalline core fiber with borosilicate glass cladding. The luminescent spectrum is fitted by Gaussian profiles, showing a thermal-induced interconversion between F+ and F22+ centers.

Fig. 8
Fig. 8

White light output power as a function of incident pump power, showing a maximum output power up to milliwatt order.

Tables (1)

Tables Icon

Table 1 Comparison of Defect Center Emissions

Equations (4)

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

Ti 4+ +hν 325nm Ti 3+ +h + (Ti 4+ )* Ti 4+ +hν 420nm ,
1 2 O 2 +2Ti Al × O O × + 2 3 V Al ''' +2Ti Al ,
1 2 O 2 +V O +2Ti Al × O O × +2Ti Al .
2 F + F 2 2+ +ϕ.

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