Abstract

We report a fiber optic photoluminescence (PL) measurement system using a novel hybrid probe composed of a series of single mode fiber (SMF) and double-clad fiber (DCF) terminated with a coreless silica fiber (CSF) segment and glass micro-lens formed on its cleaved-facet. The fiber probe provided a good guidance and focusing capability for the excitation photon with a focal length of 125 μm and a beam diameter of 13.6 μm. Utilizing a special DCF-to-DCF coupling scheme, the photoluminescence signals were efficiently collected and delivered to a photodetector with a low loss. Utilizing the proposed system, PL morphology was investigated over a 200 × 200 μm2 area for two types of InGaN/GaN blue light emitting diode (LED) epi-wafers grown on 1) an un-patterned sapphire substrate (UPSS), and 2) a patterned sapphire substrate (PSS). The uniformity in the relative PL intensity and the spectral uniformity in terms of the peak PL wavelength were experimentally compared and analyzed.

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  1. J. Wilson and J. F. B. Hawkes, Optoelectronics: An introduction (Prentice Hall, 1983).
  2. K. P. O’Donnell, M. J. Tobin, S. C. Bayliss, and W. Van Der Stricht, “Confocal microscopy and spectroscopy of InGaN epilayers on sapphire,” J. Microsc.193(2), 105–108 (1999).
    [CrossRef]
  3. K. Okamoto, A. Kaneta, Y. Kawakami, S. Fujita, J. Choi, M. Terazima, and T. Mukai, “Confocal microphotoluminescence of InGaN-based light-emitting diodes,” J. Appl. Phys.98(6), 064503 (2005).
    [CrossRef]
  4. R. Jayakrishan, T. Sebastian, C. S. Kartha, and K. P. Vijayakumar, “Room Temperature Photoluminescence Surface Mapping,” J. Phys.: Conf. Ser.28, 62–65 (2006).
    [CrossRef]
  5. L. Wang, H. Y. Choi, Y. Jung, B. H. Lee, and K. T. Kim, “Optical probe based on double-clad optical fiber for fluorescence spectroscopy,” Opt. Express15(26), 17681–17689 (2007).
    [CrossRef] [PubMed]
  6. R. Micheletto, N. Yoshimatsu, A. Kaneta, Y. Kawakami, and S. Fujita, “Indium concentration influence on PL spatial inhomogeneity in InGaN single quantum well structures detected by original low-cost near-field probes,” Appl. Surf. Sci.229(1–4), 338–345 (2004).
    [CrossRef]
  7. C. Li, M. Gao, C. Ding, X. Zhang, L. Zhang, Q. Chen, and L.-M. Peng, “In situ comprehensive characterization of optoelectronic nanomaterials for device purposes,” Nanotechnology20(17), 175703 (2009).
    [CrossRef] [PubMed]
  8. S. Nakamura and G. Fasol, The Blue Laser Diode (Springer, Heidelberg, 1997).
  9. T. Wang, T. Shirahama, H. B. Sun, H. X. Wang, J. Bai, S. Sakai, and H. Misawa, “Influence of buffer layer and growth temperature on the properties of an undoped GaN layer grown on sapphire substrate by metalorganic chemical vapor deposition,” Appl. Phys. Lett.76(16), 2220–2222 (2000).
    [CrossRef]
  10. T. Mukai, K. Takekawa, and S. Nakamura, “InGaN-based blue light-emitting diodes grown on epitaxially laterally overgrown GaN substrates,” Jpn. J. Appl. Phys.37(Part 2, No. 7B), L839–L841 (1998).
    [CrossRef]
  11. K. Tadatomo, H. Okagawa, Y. Ohuchi, T. Tsunekawa, Y. Imada, M. Kato, and T. Taguchi, “High output power InGaN ultraviolet light emitting diodes fabricated on patterned substrates using metalorganic vapor phase epitaxy,” Jpn. J. Appl. Phys.40(Part 2, No. 6B), L583–L585 (2001).
    [CrossRef]
  12. M. Yamada, T. Mitani, Y. Narukawa, S. Shioji, I. Niki, S. Sonobe, K. Deguchi, M. Sano, and T. Mukai, “InGaN-based near-ultraviolet and blue-light-emitting diodes with high external quantum efficiency using a patterned sapphire substrate and a mesh electrode,” Jpn. J. Appl. Phys.41(Part 2, No. 12B), L1431–L1433 (2002).
    [CrossRef]
  13. D. S. Wuu, W. K. Wang, W. C. Shih, R. H. Horng, C. E. Lee, W. Y. Lin, and J. S. Fang, “Enhanced output power of near-ultraviolet InGaN-GaN LEDs grown on patterned sapphire substrates,” IEEE Photon. Technol. Lett.17(2), 288–290 (2005).
    [CrossRef]
  14. L. Zenteno, “High-power double-clad fiber lasers,” J. Lightwave Technol.11(9), 1435–1446 (1993).
    [CrossRef]
  15. E. G. Neumann, Single Mode Fibers (Springer-Verlag 1988), Chap 6.
  16. F. P. Kapron, D. B. Keck, and R. D. Maurer, “Radiation losses in glass optical waveguides,” Appl. Phys. Lett.17(10), 423–425 (1970).
    [CrossRef]
  17. K. R. Kim and K. Oh, “All fiber spot-size transformer for efficient free-space optical interconnecting devices,” Appl. Opt.42, 6261–6266 (2003).
    [CrossRef] [PubMed]
  18. S. Y. Ryu, H. Y. Choi, J. Na, W. J. Choi, and B. H. Lee, “Lensed fiber probes designed as an alternative to bulk probes in optical coherence tomography,” Appl. Opt.47(10), 1510–1516 (2008).
    [CrossRef] [PubMed]
  19. S. Lemire-Renaud, M. Rivard, M. Strupler, D. Morneau, F. Verpillat, X. Daxhelet, N. Godbout, and C. Boudoux, “Double-clad fiber coupler for endoscopy,” Opt. Express18(10), 9755–9764 (2010).
    [CrossRef] [PubMed]
  20. S. Y. Ryu, H. Y. Choi, J. Na, E. S. Choi, and B. H. Lee, “Combined system of optical coherence tomography and fluorescence spectroscopy based on double-cladding fiber,” Opt. Lett.33(20), 2347–2349 (2008).
    [CrossRef] [PubMed]
  21. B. H. Lee, J. B. Eom, K. S. Park, S. J. Park, and M. J. Ju, “Specialty fiber coupler: fabrications and applications,” J. Opt. Soc. Korea14(4), 326–332 (2010).
    [CrossRef]
  22. A. W. Snyder and J. D. Love, Optical Waveguide Theory (Chapman & Hall 1983) pp. 27–29.
  23. J. Bures, S. Lacroix, and J. Lapierre, “Analyse d’un coupleur bidirectionnel a fibres optiques monomodes fusionnees,” Appl. Opt.22(12), 1918–1922 (1983).
    [CrossRef] [PubMed]
  24. M. Koike, N. Shibata, H. Kato, and Y. Takahashi, “Development of high efficiency GaN-based multiquantum-well light-emitting diodes and their applications,” IEEE J. Sel. Top. Quantum Electron.8(2), 271–277 (2002).
    [CrossRef]
  25. F. K. Yam and Z. Hassan, “Innovative advances in LED technology,” Microelectron. J.36(2), 129–137 (2005).
    [CrossRef]
  26. Z. H. Feng, Y. D. Qi, Z. D. Lu, and K. M. Lau, “GaN-based blue light-emitting diodes grown and fabricated on patterned sapphire substrates by metalorganic vapor-phase epitaxy,” J. Cryst. Growth272(1-4), 327–332 (2004).
    [CrossRef]
  27. J.-H. Chen, Z.-C. Feng, H.-L. Tsai, J.-R. Yang, P. Li, C. Wetzel, T. Detchprohm, and J. Nelson, “Optical and structural properties of InGaN/GaN multiple quantum well structure grown by metalorganic chemical vapor deposition,” Thin Solid Films498(1-2), 123–127 (2006).
    [CrossRef]
  28. S. J. Leem, Y. C. Shin, E. H. Kim, C. M. Kim, B. G. Lee, Y. Moon, I. H. Lee, and T. G. Kim, “Optimization of InGaN/GaN multiple quantum well layers by a two-step varied-barrier-growth temperature method,” Semicond. Sci. Technol.23(12), 125039 (2008).
    [CrossRef]

2010

2009

C. Li, M. Gao, C. Ding, X. Zhang, L. Zhang, Q. Chen, and L.-M. Peng, “In situ comprehensive characterization of optoelectronic nanomaterials for device purposes,” Nanotechnology20(17), 175703 (2009).
[CrossRef] [PubMed]

2008

2007

2006

J.-H. Chen, Z.-C. Feng, H.-L. Tsai, J.-R. Yang, P. Li, C. Wetzel, T. Detchprohm, and J. Nelson, “Optical and structural properties of InGaN/GaN multiple quantum well structure grown by metalorganic chemical vapor deposition,” Thin Solid Films498(1-2), 123–127 (2006).
[CrossRef]

R. Jayakrishan, T. Sebastian, C. S. Kartha, and K. P. Vijayakumar, “Room Temperature Photoluminescence Surface Mapping,” J. Phys.: Conf. Ser.28, 62–65 (2006).
[CrossRef]

2005

F. K. Yam and Z. Hassan, “Innovative advances in LED technology,” Microelectron. J.36(2), 129–137 (2005).
[CrossRef]

K. Okamoto, A. Kaneta, Y. Kawakami, S. Fujita, J. Choi, M. Terazima, and T. Mukai, “Confocal microphotoluminescence of InGaN-based light-emitting diodes,” J. Appl. Phys.98(6), 064503 (2005).
[CrossRef]

D. S. Wuu, W. K. Wang, W. C. Shih, R. H. Horng, C. E. Lee, W. Y. Lin, and J. S. Fang, “Enhanced output power of near-ultraviolet InGaN-GaN LEDs grown on patterned sapphire substrates,” IEEE Photon. Technol. Lett.17(2), 288–290 (2005).
[CrossRef]

2004

R. Micheletto, N. Yoshimatsu, A. Kaneta, Y. Kawakami, and S. Fujita, “Indium concentration influence on PL spatial inhomogeneity in InGaN single quantum well structures detected by original low-cost near-field probes,” Appl. Surf. Sci.229(1–4), 338–345 (2004).
[CrossRef]

Z. H. Feng, Y. D. Qi, Z. D. Lu, and K. M. Lau, “GaN-based blue light-emitting diodes grown and fabricated on patterned sapphire substrates by metalorganic vapor-phase epitaxy,” J. Cryst. Growth272(1-4), 327–332 (2004).
[CrossRef]

2003

2002

M. Koike, N. Shibata, H. Kato, and Y. Takahashi, “Development of high efficiency GaN-based multiquantum-well light-emitting diodes and their applications,” IEEE J. Sel. Top. Quantum Electron.8(2), 271–277 (2002).
[CrossRef]

M. Yamada, T. Mitani, Y. Narukawa, S. Shioji, I. Niki, S. Sonobe, K. Deguchi, M. Sano, and T. Mukai, “InGaN-based near-ultraviolet and blue-light-emitting diodes with high external quantum efficiency using a patterned sapphire substrate and a mesh electrode,” Jpn. J. Appl. Phys.41(Part 2, No. 12B), L1431–L1433 (2002).
[CrossRef]

2001

K. Tadatomo, H. Okagawa, Y. Ohuchi, T. Tsunekawa, Y. Imada, M. Kato, and T. Taguchi, “High output power InGaN ultraviolet light emitting diodes fabricated on patterned substrates using metalorganic vapor phase epitaxy,” Jpn. J. Appl. Phys.40(Part 2, No. 6B), L583–L585 (2001).
[CrossRef]

2000

T. Wang, T. Shirahama, H. B. Sun, H. X. Wang, J. Bai, S. Sakai, and H. Misawa, “Influence of buffer layer and growth temperature on the properties of an undoped GaN layer grown on sapphire substrate by metalorganic chemical vapor deposition,” Appl. Phys. Lett.76(16), 2220–2222 (2000).
[CrossRef]

1999

K. P. O’Donnell, M. J. Tobin, S. C. Bayliss, and W. Van Der Stricht, “Confocal microscopy and spectroscopy of InGaN epilayers on sapphire,” J. Microsc.193(2), 105–108 (1999).
[CrossRef]

1998

T. Mukai, K. Takekawa, and S. Nakamura, “InGaN-based blue light-emitting diodes grown on epitaxially laterally overgrown GaN substrates,” Jpn. J. Appl. Phys.37(Part 2, No. 7B), L839–L841 (1998).
[CrossRef]

1993

L. Zenteno, “High-power double-clad fiber lasers,” J. Lightwave Technol.11(9), 1435–1446 (1993).
[CrossRef]

1983

1970

F. P. Kapron, D. B. Keck, and R. D. Maurer, “Radiation losses in glass optical waveguides,” Appl. Phys. Lett.17(10), 423–425 (1970).
[CrossRef]

Bai, J.

T. Wang, T. Shirahama, H. B. Sun, H. X. Wang, J. Bai, S. Sakai, and H. Misawa, “Influence of buffer layer and growth temperature on the properties of an undoped GaN layer grown on sapphire substrate by metalorganic chemical vapor deposition,” Appl. Phys. Lett.76(16), 2220–2222 (2000).
[CrossRef]

Bayliss, S. C.

K. P. O’Donnell, M. J. Tobin, S. C. Bayliss, and W. Van Der Stricht, “Confocal microscopy and spectroscopy of InGaN epilayers on sapphire,” J. Microsc.193(2), 105–108 (1999).
[CrossRef]

Boudoux, C.

Bures, J.

Chen, J.-H.

J.-H. Chen, Z.-C. Feng, H.-L. Tsai, J.-R. Yang, P. Li, C. Wetzel, T. Detchprohm, and J. Nelson, “Optical and structural properties of InGaN/GaN multiple quantum well structure grown by metalorganic chemical vapor deposition,” Thin Solid Films498(1-2), 123–127 (2006).
[CrossRef]

Chen, Q.

C. Li, M. Gao, C. Ding, X. Zhang, L. Zhang, Q. Chen, and L.-M. Peng, “In situ comprehensive characterization of optoelectronic nanomaterials for device purposes,” Nanotechnology20(17), 175703 (2009).
[CrossRef] [PubMed]

Choi, E. S.

Choi, H. Y.

Choi, J.

K. Okamoto, A. Kaneta, Y. Kawakami, S. Fujita, J. Choi, M. Terazima, and T. Mukai, “Confocal microphotoluminescence of InGaN-based light-emitting diodes,” J. Appl. Phys.98(6), 064503 (2005).
[CrossRef]

Choi, W. J.

Daxhelet, X.

Deguchi, K.

M. Yamada, T. Mitani, Y. Narukawa, S. Shioji, I. Niki, S. Sonobe, K. Deguchi, M. Sano, and T. Mukai, “InGaN-based near-ultraviolet and blue-light-emitting diodes with high external quantum efficiency using a patterned sapphire substrate and a mesh electrode,” Jpn. J. Appl. Phys.41(Part 2, No. 12B), L1431–L1433 (2002).
[CrossRef]

Detchprohm, T.

J.-H. Chen, Z.-C. Feng, H.-L. Tsai, J.-R. Yang, P. Li, C. Wetzel, T. Detchprohm, and J. Nelson, “Optical and structural properties of InGaN/GaN multiple quantum well structure grown by metalorganic chemical vapor deposition,” Thin Solid Films498(1-2), 123–127 (2006).
[CrossRef]

Ding, C.

C. Li, M. Gao, C. Ding, X. Zhang, L. Zhang, Q. Chen, and L.-M. Peng, “In situ comprehensive characterization of optoelectronic nanomaterials for device purposes,” Nanotechnology20(17), 175703 (2009).
[CrossRef] [PubMed]

Eom, J. B.

Fang, J. S.

D. S. Wuu, W. K. Wang, W. C. Shih, R. H. Horng, C. E. Lee, W. Y. Lin, and J. S. Fang, “Enhanced output power of near-ultraviolet InGaN-GaN LEDs grown on patterned sapphire substrates,” IEEE Photon. Technol. Lett.17(2), 288–290 (2005).
[CrossRef]

Feng, Z. H.

Z. H. Feng, Y. D. Qi, Z. D. Lu, and K. M. Lau, “GaN-based blue light-emitting diodes grown and fabricated on patterned sapphire substrates by metalorganic vapor-phase epitaxy,” J. Cryst. Growth272(1-4), 327–332 (2004).
[CrossRef]

Feng, Z.-C.

J.-H. Chen, Z.-C. Feng, H.-L. Tsai, J.-R. Yang, P. Li, C. Wetzel, T. Detchprohm, and J. Nelson, “Optical and structural properties of InGaN/GaN multiple quantum well structure grown by metalorganic chemical vapor deposition,” Thin Solid Films498(1-2), 123–127 (2006).
[CrossRef]

Fujita, S.

K. Okamoto, A. Kaneta, Y. Kawakami, S. Fujita, J. Choi, M. Terazima, and T. Mukai, “Confocal microphotoluminescence of InGaN-based light-emitting diodes,” J. Appl. Phys.98(6), 064503 (2005).
[CrossRef]

R. Micheletto, N. Yoshimatsu, A. Kaneta, Y. Kawakami, and S. Fujita, “Indium concentration influence on PL spatial inhomogeneity in InGaN single quantum well structures detected by original low-cost near-field probes,” Appl. Surf. Sci.229(1–4), 338–345 (2004).
[CrossRef]

Gao, M.

C. Li, M. Gao, C. Ding, X. Zhang, L. Zhang, Q. Chen, and L.-M. Peng, “In situ comprehensive characterization of optoelectronic nanomaterials for device purposes,” Nanotechnology20(17), 175703 (2009).
[CrossRef] [PubMed]

Godbout, N.

Hassan, Z.

F. K. Yam and Z. Hassan, “Innovative advances in LED technology,” Microelectron. J.36(2), 129–137 (2005).
[CrossRef]

Horng, R. H.

D. S. Wuu, W. K. Wang, W. C. Shih, R. H. Horng, C. E. Lee, W. Y. Lin, and J. S. Fang, “Enhanced output power of near-ultraviolet InGaN-GaN LEDs grown on patterned sapphire substrates,” IEEE Photon. Technol. Lett.17(2), 288–290 (2005).
[CrossRef]

Imada, Y.

K. Tadatomo, H. Okagawa, Y. Ohuchi, T. Tsunekawa, Y. Imada, M. Kato, and T. Taguchi, “High output power InGaN ultraviolet light emitting diodes fabricated on patterned substrates using metalorganic vapor phase epitaxy,” Jpn. J. Appl. Phys.40(Part 2, No. 6B), L583–L585 (2001).
[CrossRef]

Jayakrishan, R.

R. Jayakrishan, T. Sebastian, C. S. Kartha, and K. P. Vijayakumar, “Room Temperature Photoluminescence Surface Mapping,” J. Phys.: Conf. Ser.28, 62–65 (2006).
[CrossRef]

Ju, M. J.

Jung, Y.

Kaneta, A.

K. Okamoto, A. Kaneta, Y. Kawakami, S. Fujita, J. Choi, M. Terazima, and T. Mukai, “Confocal microphotoluminescence of InGaN-based light-emitting diodes,” J. Appl. Phys.98(6), 064503 (2005).
[CrossRef]

R. Micheletto, N. Yoshimatsu, A. Kaneta, Y. Kawakami, and S. Fujita, “Indium concentration influence on PL spatial inhomogeneity in InGaN single quantum well structures detected by original low-cost near-field probes,” Appl. Surf. Sci.229(1–4), 338–345 (2004).
[CrossRef]

Kapron, F. P.

F. P. Kapron, D. B. Keck, and R. D. Maurer, “Radiation losses in glass optical waveguides,” Appl. Phys. Lett.17(10), 423–425 (1970).
[CrossRef]

Kartha, C. S.

R. Jayakrishan, T. Sebastian, C. S. Kartha, and K. P. Vijayakumar, “Room Temperature Photoluminescence Surface Mapping,” J. Phys.: Conf. Ser.28, 62–65 (2006).
[CrossRef]

Kato, H.

M. Koike, N. Shibata, H. Kato, and Y. Takahashi, “Development of high efficiency GaN-based multiquantum-well light-emitting diodes and their applications,” IEEE J. Sel. Top. Quantum Electron.8(2), 271–277 (2002).
[CrossRef]

Kato, M.

K. Tadatomo, H. Okagawa, Y. Ohuchi, T. Tsunekawa, Y. Imada, M. Kato, and T. Taguchi, “High output power InGaN ultraviolet light emitting diodes fabricated on patterned substrates using metalorganic vapor phase epitaxy,” Jpn. J. Appl. Phys.40(Part 2, No. 6B), L583–L585 (2001).
[CrossRef]

Kawakami, Y.

K. Okamoto, A. Kaneta, Y. Kawakami, S. Fujita, J. Choi, M. Terazima, and T. Mukai, “Confocal microphotoluminescence of InGaN-based light-emitting diodes,” J. Appl. Phys.98(6), 064503 (2005).
[CrossRef]

R. Micheletto, N. Yoshimatsu, A. Kaneta, Y. Kawakami, and S. Fujita, “Indium concentration influence on PL spatial inhomogeneity in InGaN single quantum well structures detected by original low-cost near-field probes,” Appl. Surf. Sci.229(1–4), 338–345 (2004).
[CrossRef]

Keck, D. B.

F. P. Kapron, D. B. Keck, and R. D. Maurer, “Radiation losses in glass optical waveguides,” Appl. Phys. Lett.17(10), 423–425 (1970).
[CrossRef]

Kim, C. M.

S. J. Leem, Y. C. Shin, E. H. Kim, C. M. Kim, B. G. Lee, Y. Moon, I. H. Lee, and T. G. Kim, “Optimization of InGaN/GaN multiple quantum well layers by a two-step varied-barrier-growth temperature method,” Semicond. Sci. Technol.23(12), 125039 (2008).
[CrossRef]

Kim, E. H.

S. J. Leem, Y. C. Shin, E. H. Kim, C. M. Kim, B. G. Lee, Y. Moon, I. H. Lee, and T. G. Kim, “Optimization of InGaN/GaN multiple quantum well layers by a two-step varied-barrier-growth temperature method,” Semicond. Sci. Technol.23(12), 125039 (2008).
[CrossRef]

Kim, K. R.

Kim, K. T.

Kim, T. G.

S. J. Leem, Y. C. Shin, E. H. Kim, C. M. Kim, B. G. Lee, Y. Moon, I. H. Lee, and T. G. Kim, “Optimization of InGaN/GaN multiple quantum well layers by a two-step varied-barrier-growth temperature method,” Semicond. Sci. Technol.23(12), 125039 (2008).
[CrossRef]

Koike, M.

M. Koike, N. Shibata, H. Kato, and Y. Takahashi, “Development of high efficiency GaN-based multiquantum-well light-emitting diodes and their applications,” IEEE J. Sel. Top. Quantum Electron.8(2), 271–277 (2002).
[CrossRef]

Lacroix, S.

Lapierre, J.

Lau, K. M.

Z. H. Feng, Y. D. Qi, Z. D. Lu, and K. M. Lau, “GaN-based blue light-emitting diodes grown and fabricated on patterned sapphire substrates by metalorganic vapor-phase epitaxy,” J. Cryst. Growth272(1-4), 327–332 (2004).
[CrossRef]

Lee, B. G.

S. J. Leem, Y. C. Shin, E. H. Kim, C. M. Kim, B. G. Lee, Y. Moon, I. H. Lee, and T. G. Kim, “Optimization of InGaN/GaN multiple quantum well layers by a two-step varied-barrier-growth temperature method,” Semicond. Sci. Technol.23(12), 125039 (2008).
[CrossRef]

Lee, B. H.

Lee, C. E.

D. S. Wuu, W. K. Wang, W. C. Shih, R. H. Horng, C. E. Lee, W. Y. Lin, and J. S. Fang, “Enhanced output power of near-ultraviolet InGaN-GaN LEDs grown on patterned sapphire substrates,” IEEE Photon. Technol. Lett.17(2), 288–290 (2005).
[CrossRef]

Lee, I. H.

S. J. Leem, Y. C. Shin, E. H. Kim, C. M. Kim, B. G. Lee, Y. Moon, I. H. Lee, and T. G. Kim, “Optimization of InGaN/GaN multiple quantum well layers by a two-step varied-barrier-growth temperature method,” Semicond. Sci. Technol.23(12), 125039 (2008).
[CrossRef]

Leem, S. J.

S. J. Leem, Y. C. Shin, E. H. Kim, C. M. Kim, B. G. Lee, Y. Moon, I. H. Lee, and T. G. Kim, “Optimization of InGaN/GaN multiple quantum well layers by a two-step varied-barrier-growth temperature method,” Semicond. Sci. Technol.23(12), 125039 (2008).
[CrossRef]

Lemire-Renaud, S.

Li, C.

C. Li, M. Gao, C. Ding, X. Zhang, L. Zhang, Q. Chen, and L.-M. Peng, “In situ comprehensive characterization of optoelectronic nanomaterials for device purposes,” Nanotechnology20(17), 175703 (2009).
[CrossRef] [PubMed]

Li, P.

J.-H. Chen, Z.-C. Feng, H.-L. Tsai, J.-R. Yang, P. Li, C. Wetzel, T. Detchprohm, and J. Nelson, “Optical and structural properties of InGaN/GaN multiple quantum well structure grown by metalorganic chemical vapor deposition,” Thin Solid Films498(1-2), 123–127 (2006).
[CrossRef]

Lin, W. Y.

D. S. Wuu, W. K. Wang, W. C. Shih, R. H. Horng, C. E. Lee, W. Y. Lin, and J. S. Fang, “Enhanced output power of near-ultraviolet InGaN-GaN LEDs grown on patterned sapphire substrates,” IEEE Photon. Technol. Lett.17(2), 288–290 (2005).
[CrossRef]

Lu, Z. D.

Z. H. Feng, Y. D. Qi, Z. D. Lu, and K. M. Lau, “GaN-based blue light-emitting diodes grown and fabricated on patterned sapphire substrates by metalorganic vapor-phase epitaxy,” J. Cryst. Growth272(1-4), 327–332 (2004).
[CrossRef]

Maurer, R. D.

F. P. Kapron, D. B. Keck, and R. D. Maurer, “Radiation losses in glass optical waveguides,” Appl. Phys. Lett.17(10), 423–425 (1970).
[CrossRef]

Micheletto, R.

R. Micheletto, N. Yoshimatsu, A. Kaneta, Y. Kawakami, and S. Fujita, “Indium concentration influence on PL spatial inhomogeneity in InGaN single quantum well structures detected by original low-cost near-field probes,” Appl. Surf. Sci.229(1–4), 338–345 (2004).
[CrossRef]

Misawa, H.

T. Wang, T. Shirahama, H. B. Sun, H. X. Wang, J. Bai, S. Sakai, and H. Misawa, “Influence of buffer layer and growth temperature on the properties of an undoped GaN layer grown on sapphire substrate by metalorganic chemical vapor deposition,” Appl. Phys. Lett.76(16), 2220–2222 (2000).
[CrossRef]

Mitani, T.

M. Yamada, T. Mitani, Y. Narukawa, S. Shioji, I. Niki, S. Sonobe, K. Deguchi, M. Sano, and T. Mukai, “InGaN-based near-ultraviolet and blue-light-emitting diodes with high external quantum efficiency using a patterned sapphire substrate and a mesh electrode,” Jpn. J. Appl. Phys.41(Part 2, No. 12B), L1431–L1433 (2002).
[CrossRef]

Moon, Y.

S. J. Leem, Y. C. Shin, E. H. Kim, C. M. Kim, B. G. Lee, Y. Moon, I. H. Lee, and T. G. Kim, “Optimization of InGaN/GaN multiple quantum well layers by a two-step varied-barrier-growth temperature method,” Semicond. Sci. Technol.23(12), 125039 (2008).
[CrossRef]

Morneau, D.

Mukai, T.

K. Okamoto, A. Kaneta, Y. Kawakami, S. Fujita, J. Choi, M. Terazima, and T. Mukai, “Confocal microphotoluminescence of InGaN-based light-emitting diodes,” J. Appl. Phys.98(6), 064503 (2005).
[CrossRef]

M. Yamada, T. Mitani, Y. Narukawa, S. Shioji, I. Niki, S. Sonobe, K. Deguchi, M. Sano, and T. Mukai, “InGaN-based near-ultraviolet and blue-light-emitting diodes with high external quantum efficiency using a patterned sapphire substrate and a mesh electrode,” Jpn. J. Appl. Phys.41(Part 2, No. 12B), L1431–L1433 (2002).
[CrossRef]

T. Mukai, K. Takekawa, and S. Nakamura, “InGaN-based blue light-emitting diodes grown on epitaxially laterally overgrown GaN substrates,” Jpn. J. Appl. Phys.37(Part 2, No. 7B), L839–L841 (1998).
[CrossRef]

Na, J.

Nakamura, S.

T. Mukai, K. Takekawa, and S. Nakamura, “InGaN-based blue light-emitting diodes grown on epitaxially laterally overgrown GaN substrates,” Jpn. J. Appl. Phys.37(Part 2, No. 7B), L839–L841 (1998).
[CrossRef]

Narukawa, Y.

M. Yamada, T. Mitani, Y. Narukawa, S. Shioji, I. Niki, S. Sonobe, K. Deguchi, M. Sano, and T. Mukai, “InGaN-based near-ultraviolet and blue-light-emitting diodes with high external quantum efficiency using a patterned sapphire substrate and a mesh electrode,” Jpn. J. Appl. Phys.41(Part 2, No. 12B), L1431–L1433 (2002).
[CrossRef]

Nelson, J.

J.-H. Chen, Z.-C. Feng, H.-L. Tsai, J.-R. Yang, P. Li, C. Wetzel, T. Detchprohm, and J. Nelson, “Optical and structural properties of InGaN/GaN multiple quantum well structure grown by metalorganic chemical vapor deposition,” Thin Solid Films498(1-2), 123–127 (2006).
[CrossRef]

Niki, I.

M. Yamada, T. Mitani, Y. Narukawa, S. Shioji, I. Niki, S. Sonobe, K. Deguchi, M. Sano, and T. Mukai, “InGaN-based near-ultraviolet and blue-light-emitting diodes with high external quantum efficiency using a patterned sapphire substrate and a mesh electrode,” Jpn. J. Appl. Phys.41(Part 2, No. 12B), L1431–L1433 (2002).
[CrossRef]

O’Donnell, K. P.

K. P. O’Donnell, M. J. Tobin, S. C. Bayliss, and W. Van Der Stricht, “Confocal microscopy and spectroscopy of InGaN epilayers on sapphire,” J. Microsc.193(2), 105–108 (1999).
[CrossRef]

Oh, K.

Ohuchi, Y.

K. Tadatomo, H. Okagawa, Y. Ohuchi, T. Tsunekawa, Y. Imada, M. Kato, and T. Taguchi, “High output power InGaN ultraviolet light emitting diodes fabricated on patterned substrates using metalorganic vapor phase epitaxy,” Jpn. J. Appl. Phys.40(Part 2, No. 6B), L583–L585 (2001).
[CrossRef]

Okagawa, H.

K. Tadatomo, H. Okagawa, Y. Ohuchi, T. Tsunekawa, Y. Imada, M. Kato, and T. Taguchi, “High output power InGaN ultraviolet light emitting diodes fabricated on patterned substrates using metalorganic vapor phase epitaxy,” Jpn. J. Appl. Phys.40(Part 2, No. 6B), L583–L585 (2001).
[CrossRef]

Okamoto, K.

K. Okamoto, A. Kaneta, Y. Kawakami, S. Fujita, J. Choi, M. Terazima, and T. Mukai, “Confocal microphotoluminescence of InGaN-based light-emitting diodes,” J. Appl. Phys.98(6), 064503 (2005).
[CrossRef]

Park, K. S.

Park, S. J.

Peng, L.-M.

C. Li, M. Gao, C. Ding, X. Zhang, L. Zhang, Q. Chen, and L.-M. Peng, “In situ comprehensive characterization of optoelectronic nanomaterials for device purposes,” Nanotechnology20(17), 175703 (2009).
[CrossRef] [PubMed]

Qi, Y. D.

Z. H. Feng, Y. D. Qi, Z. D. Lu, and K. M. Lau, “GaN-based blue light-emitting diodes grown and fabricated on patterned sapphire substrates by metalorganic vapor-phase epitaxy,” J. Cryst. Growth272(1-4), 327–332 (2004).
[CrossRef]

Rivard, M.

Ryu, S. Y.

Sakai, S.

T. Wang, T. Shirahama, H. B. Sun, H. X. Wang, J. Bai, S. Sakai, and H. Misawa, “Influence of buffer layer and growth temperature on the properties of an undoped GaN layer grown on sapphire substrate by metalorganic chemical vapor deposition,” Appl. Phys. Lett.76(16), 2220–2222 (2000).
[CrossRef]

Sano, M.

M. Yamada, T. Mitani, Y. Narukawa, S. Shioji, I. Niki, S. Sonobe, K. Deguchi, M. Sano, and T. Mukai, “InGaN-based near-ultraviolet and blue-light-emitting diodes with high external quantum efficiency using a patterned sapphire substrate and a mesh electrode,” Jpn. J. Appl. Phys.41(Part 2, No. 12B), L1431–L1433 (2002).
[CrossRef]

Sebastian, T.

R. Jayakrishan, T. Sebastian, C. S. Kartha, and K. P. Vijayakumar, “Room Temperature Photoluminescence Surface Mapping,” J. Phys.: Conf. Ser.28, 62–65 (2006).
[CrossRef]

Shibata, N.

M. Koike, N. Shibata, H. Kato, and Y. Takahashi, “Development of high efficiency GaN-based multiquantum-well light-emitting diodes and their applications,” IEEE J. Sel. Top. Quantum Electron.8(2), 271–277 (2002).
[CrossRef]

Shih, W. C.

D. S. Wuu, W. K. Wang, W. C. Shih, R. H. Horng, C. E. Lee, W. Y. Lin, and J. S. Fang, “Enhanced output power of near-ultraviolet InGaN-GaN LEDs grown on patterned sapphire substrates,” IEEE Photon. Technol. Lett.17(2), 288–290 (2005).
[CrossRef]

Shin, Y. C.

S. J. Leem, Y. C. Shin, E. H. Kim, C. M. Kim, B. G. Lee, Y. Moon, I. H. Lee, and T. G. Kim, “Optimization of InGaN/GaN multiple quantum well layers by a two-step varied-barrier-growth temperature method,” Semicond. Sci. Technol.23(12), 125039 (2008).
[CrossRef]

Shioji, S.

M. Yamada, T. Mitani, Y. Narukawa, S. Shioji, I. Niki, S. Sonobe, K. Deguchi, M. Sano, and T. Mukai, “InGaN-based near-ultraviolet and blue-light-emitting diodes with high external quantum efficiency using a patterned sapphire substrate and a mesh electrode,” Jpn. J. Appl. Phys.41(Part 2, No. 12B), L1431–L1433 (2002).
[CrossRef]

Shirahama, T.

T. Wang, T. Shirahama, H. B. Sun, H. X. Wang, J. Bai, S. Sakai, and H. Misawa, “Influence of buffer layer and growth temperature on the properties of an undoped GaN layer grown on sapphire substrate by metalorganic chemical vapor deposition,” Appl. Phys. Lett.76(16), 2220–2222 (2000).
[CrossRef]

Sonobe, S.

M. Yamada, T. Mitani, Y. Narukawa, S. Shioji, I. Niki, S. Sonobe, K. Deguchi, M. Sano, and T. Mukai, “InGaN-based near-ultraviolet and blue-light-emitting diodes with high external quantum efficiency using a patterned sapphire substrate and a mesh electrode,” Jpn. J. Appl. Phys.41(Part 2, No. 12B), L1431–L1433 (2002).
[CrossRef]

Strupler, M.

Sun, H. B.

T. Wang, T. Shirahama, H. B. Sun, H. X. Wang, J. Bai, S. Sakai, and H. Misawa, “Influence of buffer layer and growth temperature on the properties of an undoped GaN layer grown on sapphire substrate by metalorganic chemical vapor deposition,” Appl. Phys. Lett.76(16), 2220–2222 (2000).
[CrossRef]

Tadatomo, K.

K. Tadatomo, H. Okagawa, Y. Ohuchi, T. Tsunekawa, Y. Imada, M. Kato, and T. Taguchi, “High output power InGaN ultraviolet light emitting diodes fabricated on patterned substrates using metalorganic vapor phase epitaxy,” Jpn. J. Appl. Phys.40(Part 2, No. 6B), L583–L585 (2001).
[CrossRef]

Taguchi, T.

K. Tadatomo, H. Okagawa, Y. Ohuchi, T. Tsunekawa, Y. Imada, M. Kato, and T. Taguchi, “High output power InGaN ultraviolet light emitting diodes fabricated on patterned substrates using metalorganic vapor phase epitaxy,” Jpn. J. Appl. Phys.40(Part 2, No. 6B), L583–L585 (2001).
[CrossRef]

Takahashi, Y.

M. Koike, N. Shibata, H. Kato, and Y. Takahashi, “Development of high efficiency GaN-based multiquantum-well light-emitting diodes and their applications,” IEEE J. Sel. Top. Quantum Electron.8(2), 271–277 (2002).
[CrossRef]

Takekawa, K.

T. Mukai, K. Takekawa, and S. Nakamura, “InGaN-based blue light-emitting diodes grown on epitaxially laterally overgrown GaN substrates,” Jpn. J. Appl. Phys.37(Part 2, No. 7B), L839–L841 (1998).
[CrossRef]

Terazima, M.

K. Okamoto, A. Kaneta, Y. Kawakami, S. Fujita, J. Choi, M. Terazima, and T. Mukai, “Confocal microphotoluminescence of InGaN-based light-emitting diodes,” J. Appl. Phys.98(6), 064503 (2005).
[CrossRef]

Tobin, M. J.

K. P. O’Donnell, M. J. Tobin, S. C. Bayliss, and W. Van Der Stricht, “Confocal microscopy and spectroscopy of InGaN epilayers on sapphire,” J. Microsc.193(2), 105–108 (1999).
[CrossRef]

Tsai, H.-L.

J.-H. Chen, Z.-C. Feng, H.-L. Tsai, J.-R. Yang, P. Li, C. Wetzel, T. Detchprohm, and J. Nelson, “Optical and structural properties of InGaN/GaN multiple quantum well structure grown by metalorganic chemical vapor deposition,” Thin Solid Films498(1-2), 123–127 (2006).
[CrossRef]

Tsunekawa, T.

K. Tadatomo, H. Okagawa, Y. Ohuchi, T. Tsunekawa, Y. Imada, M. Kato, and T. Taguchi, “High output power InGaN ultraviolet light emitting diodes fabricated on patterned substrates using metalorganic vapor phase epitaxy,” Jpn. J. Appl. Phys.40(Part 2, No. 6B), L583–L585 (2001).
[CrossRef]

Van Der Stricht, W.

K. P. O’Donnell, M. J. Tobin, S. C. Bayliss, and W. Van Der Stricht, “Confocal microscopy and spectroscopy of InGaN epilayers on sapphire,” J. Microsc.193(2), 105–108 (1999).
[CrossRef]

Verpillat, F.

Vijayakumar, K. P.

R. Jayakrishan, T. Sebastian, C. S. Kartha, and K. P. Vijayakumar, “Room Temperature Photoluminescence Surface Mapping,” J. Phys.: Conf. Ser.28, 62–65 (2006).
[CrossRef]

Wang, H. X.

T. Wang, T. Shirahama, H. B. Sun, H. X. Wang, J. Bai, S. Sakai, and H. Misawa, “Influence of buffer layer and growth temperature on the properties of an undoped GaN layer grown on sapphire substrate by metalorganic chemical vapor deposition,” Appl. Phys. Lett.76(16), 2220–2222 (2000).
[CrossRef]

Wang, L.

Wang, T.

T. Wang, T. Shirahama, H. B. Sun, H. X. Wang, J. Bai, S. Sakai, and H. Misawa, “Influence of buffer layer and growth temperature on the properties of an undoped GaN layer grown on sapphire substrate by metalorganic chemical vapor deposition,” Appl. Phys. Lett.76(16), 2220–2222 (2000).
[CrossRef]

Wang, W. K.

D. S. Wuu, W. K. Wang, W. C. Shih, R. H. Horng, C. E. Lee, W. Y. Lin, and J. S. Fang, “Enhanced output power of near-ultraviolet InGaN-GaN LEDs grown on patterned sapphire substrates,” IEEE Photon. Technol. Lett.17(2), 288–290 (2005).
[CrossRef]

Wetzel, C.

J.-H. Chen, Z.-C. Feng, H.-L. Tsai, J.-R. Yang, P. Li, C. Wetzel, T. Detchprohm, and J. Nelson, “Optical and structural properties of InGaN/GaN multiple quantum well structure grown by metalorganic chemical vapor deposition,” Thin Solid Films498(1-2), 123–127 (2006).
[CrossRef]

Wuu, D. S.

D. S. Wuu, W. K. Wang, W. C. Shih, R. H. Horng, C. E. Lee, W. Y. Lin, and J. S. Fang, “Enhanced output power of near-ultraviolet InGaN-GaN LEDs grown on patterned sapphire substrates,” IEEE Photon. Technol. Lett.17(2), 288–290 (2005).
[CrossRef]

Yam, F. K.

F. K. Yam and Z. Hassan, “Innovative advances in LED technology,” Microelectron. J.36(2), 129–137 (2005).
[CrossRef]

Yamada, M.

M. Yamada, T. Mitani, Y. Narukawa, S. Shioji, I. Niki, S. Sonobe, K. Deguchi, M. Sano, and T. Mukai, “InGaN-based near-ultraviolet and blue-light-emitting diodes with high external quantum efficiency using a patterned sapphire substrate and a mesh electrode,” Jpn. J. Appl. Phys.41(Part 2, No. 12B), L1431–L1433 (2002).
[CrossRef]

Yang, J.-R.

J.-H. Chen, Z.-C. Feng, H.-L. Tsai, J.-R. Yang, P. Li, C. Wetzel, T. Detchprohm, and J. Nelson, “Optical and structural properties of InGaN/GaN multiple quantum well structure grown by metalorganic chemical vapor deposition,” Thin Solid Films498(1-2), 123–127 (2006).
[CrossRef]

Yoshimatsu, N.

R. Micheletto, N. Yoshimatsu, A. Kaneta, Y. Kawakami, and S. Fujita, “Indium concentration influence on PL spatial inhomogeneity in InGaN single quantum well structures detected by original low-cost near-field probes,” Appl. Surf. Sci.229(1–4), 338–345 (2004).
[CrossRef]

Zenteno, L.

L. Zenteno, “High-power double-clad fiber lasers,” J. Lightwave Technol.11(9), 1435–1446 (1993).
[CrossRef]

Zhang, L.

C. Li, M. Gao, C. Ding, X. Zhang, L. Zhang, Q. Chen, and L.-M. Peng, “In situ comprehensive characterization of optoelectronic nanomaterials for device purposes,” Nanotechnology20(17), 175703 (2009).
[CrossRef] [PubMed]

Zhang, X.

C. Li, M. Gao, C. Ding, X. Zhang, L. Zhang, Q. Chen, and L.-M. Peng, “In situ comprehensive characterization of optoelectronic nanomaterials for device purposes,” Nanotechnology20(17), 175703 (2009).
[CrossRef] [PubMed]

Appl. Opt.

Appl. Phys. Lett.

T. Wang, T. Shirahama, H. B. Sun, H. X. Wang, J. Bai, S. Sakai, and H. Misawa, “Influence of buffer layer and growth temperature on the properties of an undoped GaN layer grown on sapphire substrate by metalorganic chemical vapor deposition,” Appl. Phys. Lett.76(16), 2220–2222 (2000).
[CrossRef]

F. P. Kapron, D. B. Keck, and R. D. Maurer, “Radiation losses in glass optical waveguides,” Appl. Phys. Lett.17(10), 423–425 (1970).
[CrossRef]

Appl. Surf. Sci.

R. Micheletto, N. Yoshimatsu, A. Kaneta, Y. Kawakami, and S. Fujita, “Indium concentration influence on PL spatial inhomogeneity in InGaN single quantum well structures detected by original low-cost near-field probes,” Appl. Surf. Sci.229(1–4), 338–345 (2004).
[CrossRef]

IEEE J. Sel. Top. Quantum Electron.

M. Koike, N. Shibata, H. Kato, and Y. Takahashi, “Development of high efficiency GaN-based multiquantum-well light-emitting diodes and their applications,” IEEE J. Sel. Top. Quantum Electron.8(2), 271–277 (2002).
[CrossRef]

IEEE Photon. Technol. Lett.

D. S. Wuu, W. K. Wang, W. C. Shih, R. H. Horng, C. E. Lee, W. Y. Lin, and J. S. Fang, “Enhanced output power of near-ultraviolet InGaN-GaN LEDs grown on patterned sapphire substrates,” IEEE Photon. Technol. Lett.17(2), 288–290 (2005).
[CrossRef]

J. Appl. Phys.

K. Okamoto, A. Kaneta, Y. Kawakami, S. Fujita, J. Choi, M. Terazima, and T. Mukai, “Confocal microphotoluminescence of InGaN-based light-emitting diodes,” J. Appl. Phys.98(6), 064503 (2005).
[CrossRef]

J. Cryst. Growth

Z. H. Feng, Y. D. Qi, Z. D. Lu, and K. M. Lau, “GaN-based blue light-emitting diodes grown and fabricated on patterned sapphire substrates by metalorganic vapor-phase epitaxy,” J. Cryst. Growth272(1-4), 327–332 (2004).
[CrossRef]

J. Lightwave Technol.

L. Zenteno, “High-power double-clad fiber lasers,” J. Lightwave Technol.11(9), 1435–1446 (1993).
[CrossRef]

J. Microsc.

K. P. O’Donnell, M. J. Tobin, S. C. Bayliss, and W. Van Der Stricht, “Confocal microscopy and spectroscopy of InGaN epilayers on sapphire,” J. Microsc.193(2), 105–108 (1999).
[CrossRef]

J. Opt. Soc. Korea

J. Phys.: Conf. Ser.

R. Jayakrishan, T. Sebastian, C. S. Kartha, and K. P. Vijayakumar, “Room Temperature Photoluminescence Surface Mapping,” J. Phys.: Conf. Ser.28, 62–65 (2006).
[CrossRef]

Jpn. J. Appl. Phys.

T. Mukai, K. Takekawa, and S. Nakamura, “InGaN-based blue light-emitting diodes grown on epitaxially laterally overgrown GaN substrates,” Jpn. J. Appl. Phys.37(Part 2, No. 7B), L839–L841 (1998).
[CrossRef]

K. Tadatomo, H. Okagawa, Y. Ohuchi, T. Tsunekawa, Y. Imada, M. Kato, and T. Taguchi, “High output power InGaN ultraviolet light emitting diodes fabricated on patterned substrates using metalorganic vapor phase epitaxy,” Jpn. J. Appl. Phys.40(Part 2, No. 6B), L583–L585 (2001).
[CrossRef]

M. Yamada, T. Mitani, Y. Narukawa, S. Shioji, I. Niki, S. Sonobe, K. Deguchi, M. Sano, and T. Mukai, “InGaN-based near-ultraviolet and blue-light-emitting diodes with high external quantum efficiency using a patterned sapphire substrate and a mesh electrode,” Jpn. J. Appl. Phys.41(Part 2, No. 12B), L1431–L1433 (2002).
[CrossRef]

Microelectron. J.

F. K. Yam and Z. Hassan, “Innovative advances in LED technology,” Microelectron. J.36(2), 129–137 (2005).
[CrossRef]

Nanotechnology

C. Li, M. Gao, C. Ding, X. Zhang, L. Zhang, Q. Chen, and L.-M. Peng, “In situ comprehensive characterization of optoelectronic nanomaterials for device purposes,” Nanotechnology20(17), 175703 (2009).
[CrossRef] [PubMed]

Opt. Express

Opt. Lett.

Semicond. Sci. Technol.

S. J. Leem, Y. C. Shin, E. H. Kim, C. M. Kim, B. G. Lee, Y. Moon, I. H. Lee, and T. G. Kim, “Optimization of InGaN/GaN multiple quantum well layers by a two-step varied-barrier-growth temperature method,” Semicond. Sci. Technol.23(12), 125039 (2008).
[CrossRef]

Thin Solid Films

J.-H. Chen, Z.-C. Feng, H.-L. Tsai, J.-R. Yang, P. Li, C. Wetzel, T. Detchprohm, and J. Nelson, “Optical and structural properties of InGaN/GaN multiple quantum well structure grown by metalorganic chemical vapor deposition,” Thin Solid Films498(1-2), 123–127 (2006).
[CrossRef]

Other

A. W. Snyder and J. D. Love, Optical Waveguide Theory (Chapman & Hall 1983) pp. 27–29.

J. Wilson and J. F. B. Hawkes, Optoelectronics: An introduction (Prentice Hall, 1983).

S. Nakamura and G. Fasol, The Blue Laser Diode (Springer, Heidelberg, 1997).

E. G. Neumann, Single Mode Fibers (Springer-Verlag 1988), Chap 6.

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Figures (7)

Fig. 1
Fig. 1

Dual cladding fiber (DCF) fabrication. (a) Recoating a single mode fiber with a low refractive index polymer in a continuous manner using an optical fiber drawing tower. (b) Structure of the DCF with a 4 μm core, 125 μm inner cladding, and 180 μm outer cladding.

Fig. 2
Fig. 2

Proposed hybrid fiber optic probe. (a) Schematic diagram for concatenated fiber structure and transformation of the guided modes in the axial direction. (b) Fabrication of the fiber-lens using a coreless silica fiber (CSF) spliced to the end of ‘output DCF. (c) Intensity profile of the excitation laser (λ = 405 nm) output at the focal length.

Fig. 3
Fig. 3

Fiber lens integrated over hybrid fiber optic probe. (a) Structure of the proposed Y-type DCF coupler integrated on the hybrid fiber optic probe, (b) Schematic diagram for collecting PL signals using the proposed all-fiber probe. Here we used TiO2 film on the end of ‘receiving arm DCF’ to collect only the PL directly excited by the focused beam on the sample wafer.

Fig. 4
Fig. 4

Schematic diagram of the proposed fiber optic PL measurement system, consisting of a laser source, spectrometer, XY-nano positioning stage, and Y-type DCF coupler including the integrated fiber probe. The violet line represents the excitation laser beam, and the green arrows represent the PL signal route from the epi-wafer.

Fig. 5
Fig. 5

Cross-sectional Scanning Electron Microscope (SEM) images of GaN LED epi-layers on (a) UPSS and (b) PSS

Fig. 6
Fig. 6

A typical PL spectrum of the InGaN/GaN LED epi-wafer measured by the proposed PL system. Here the excitation laser was at λ = 405 nm.

Fig. 7
Fig. 7

Contour maps of (a) Peak Intensity, (b) Peak Wavelength (c) FWHM of the LED epi-wafers on the UPSS (left column) and PSS (right column).

Tables (1)

Tables Icon

Table 1 Average PL peak properties for two types of LED epi-wafers.

Metrics