Skip to main content
SpringerLink
Log in

Confocal microscopy as a tool for the study of the emission characteristics of high-power LEDs

  • Published:
Applied Physics B Aims and scope Submit manuscript

Abstract

We report on an experimental set-up based on a confocal principle in order to acquire the light-intensity distribution (XZ and XY optical sections) of high-power LEDs. To be able to record the emission characteristics of millimeter-sized LEDs and to carry out the measurements with high precision the set-up consists of a moving stage and stationary rather than scanning optics, along with a lock-in amplifier in combination with a photodiode as a detection unit. The optical sections recorded provide valuable information on the light-intensity distribution and the light propagation both within transparent substrates (in case of flip-chip LEDs) as well as in the ambient of the LEDs. In order to evaluate the accuracy of the measurement technique, the impact of the numerical aperture of the objective lens on the shape of the optical sections recorded was tested for a set of different objective lenses. The method reported provides new opportunities for a direct determination not only of the amount but also the directionality of the light extraction from LEDs that are processed in order to improve the light-extraction efficiency.

This is a preview of subscription content, log in via an institution to check access.

Access this article

Log in via an institution

Price excludes VAT (USA)
Tax calculation will be finalised during checkout.

Instant access to the full article PDF.

Institutional subscriptions

Similar content being viewed by others

References

  1. E.F. Schubert, J.K. Kim, Science 308, 1274 (2005)

    Article  ADS  Google Scholar 

  2. A.A. Bergh, Phys. Stat. Solidi A 201, 2740 (2004)

    Article  ADS  Google Scholar 

  3. E.F. Schubert, J.K. Kim, H. Luo, J.Q. Xi, Rep. Prog. Phys. 69, 3069 (2006)

    Article  ADS  Google Scholar 

  4. G. Marutsuki, Y. Narukawa, T. Mitani, T. Mukai, G. Shinomiya, A. Kaneta, Y. Kawakami, S. Fujita, Phys. Stat. Solidi A 192, 110 (2002)

    Article  Google Scholar 

  5. P. Fischer, J. Christen, M. Zacharias, V. Schwegler, C. Kirchner, M. Kamp, Phys. Stat. Solidi A 176, 119 (1999)

    Article  ADS  Google Scholar 

  6. P. Fischer, J. Christen, M. Zacharias, V. Schwegler, C. Kirchner, M. Kamp, Appl. Phys. Lett. 75, 3440 (1999)

    Article  ADS  Google Scholar 

  7. K. Okamoto, A. Kaneta, Y. Kawamaki, S. Fujita, J. Choi, M. Terazima, T. Mukai, J. Appl. Phys. 98, 064503 (2005)

    Article  ADS  Google Scholar 

  8. J.M. Girkin, E. Gu, C. Griffin, H.W. Choi, M.D. Dawson, G. McConnell, Microsc. Res. Tech. 64, 293 (2004)

    Article  Google Scholar 

  9. C. Griffin, E. Gu, H.W. Choi, C.W. Jeon, J.M. Girkin, M.D. Dawson, G. McConnell, Appl. Phys. Lett. 86, 041111 (2005)

    Article  ADS  Google Scholar 

  10. H.W. Choi, C. Liu, E. Gu, G. McConnell, J.M. Girkin, I.M. Watson, M.D. Dawson, Appl. Phys. Lett. 84, 2253 (2004)

    Article  ADS  Google Scholar 

  11. H.W. Choi, E. Gu, C. Liu, J.M. Girkin, M.D. Dawson, J. Appl. Phys. 97, 063101 (2005)

    Article  ADS  Google Scholar 

  12. E. Gu, H.W. Choi, C. Liu, C. Griffin, J.M. Girkin, I.M. Watson, M.D. Dawson, G. McConnell, A.M. Gurney, Appl. Phys. Lett. 84, 2754 (2004)

    Article  ADS  Google Scholar 

  13. M.E. Gaevski, M. Shatalov, S. Wu, A.M. Khan, Mater. Res. Soc. Symp. Proc. Vol. 916, 0916-DD05-09 (2006)

  14. A.M. Khan, Phys. Stat. Solidi A 203, 1764 (2006)

    Article  ADS  Google Scholar 

  15. R.H. Webb, Rep. Prog. Phys. 59, 427 (1996)

    Article  ADS  Google Scholar 

  16. D. Semwogerere, E.R. Weeks, Encyclopedia of Biomaterials and Biomedical Engineering (Taylor and Francis, London, 2005), pp. 1–9

    Google Scholar 

  17. J.M. Girkin, G. McConnell, Microsc. Res. Tech. 67, 8 (2005)

    Article  Google Scholar 

  18. J.G. White, W.B. Amos, M. Fordham, J. Cell Biol. 105, 41 (1987)

    Article  Google Scholar 

  19. W. Denk, K. Svoboda, Neuron 18, 351 (1997)

    Google Scholar 

  20. K. Kuba, S. Nakayama, Neurosci. Res. 32, 281 (1998)

    Google Scholar 

Download references

Author information

Authors and Affiliations

  1. Institute of Nanostructured Materials and Photonics, Joanneum Research Forschungsges. mbH, Franz-Pichler Straße 30, 8160, Weiz, Austria

    L. Kuna, C. Sommer, E. Zinterl & F.P. Wenzl

  2. TridonicAtco Optoelectronics GmbH, Technologiepark 10, 8380, Jennersdorf, Austria

    P. Pachler, P. Hartmann & S. Tasch

  3. Institute of Solid State Physics, Graz University of Technology, Petersgasse 16, 8010, Graz, Austria

    G. Leising

Authors
  1. L. Kuna
    View author publications

    You can also search for this author in PubMed Google Scholar

  2. C. Sommer
    View author publications

    You can also search for this author in PubMed Google Scholar

  3. E. Zinterl
    View author publications

    You can also search for this author in PubMed Google Scholar

  4. F.P. Wenzl
    View author publications

    You can also search for this author in PubMed Google Scholar

  5. P. Pachler
    View author publications

    You can also search for this author in PubMed Google Scholar

  6. P. Hartmann
    View author publications

    You can also search for this author in PubMed Google Scholar

  7. S. Tasch
    View author publications

    You can also search for this author in PubMed Google Scholar

  8. G. Leising
    View author publications

    You can also search for this author in PubMed Google Scholar

Corresponding author

Correspondence to F.P. Wenzl.

Additional information

PACS

85.60.Bt; 85.60.Jb

Rights and permissions

Reprints and permissions

About this article

Cite this article

Kuna, L., Sommer, C., Zinterl, E. et al. Confocal microscopy as a tool for the study of the emission characteristics of high-power LEDs. Appl. Phys. B 91, 571–577 (2008). https://doi.org/10.1007/s00340-008-3031-5

Download citation

  • Received:

  • Revised:

  • Published:

  • Issue Date:

  • DOI: https://doi.org/10.1007/s00340-008-3031-5

Keywords

Search

Navigation