OSA's Digital Library

Optics Express

Optics Express

  • Editor: C. Martijn de Sterke
  • Vol. 17, Iss. 2 — Jan. 19, 2009
  • pp: 649–657

Tree array quantum cascade laser

Leonard K. Hoffmann, Matthias Klinkmüller, Elvis Mujagić, Mykhaylo P. Semtsiv, Werner Schrenk, William T. Masselink, and Gottfried Strasser  »View Author Affiliations

Optics Express, Vol. 17, Issue 2, pp. 649-657 (2009)

View Full Text Article

Enhanced HTML    Acrobat PDF (2122 KB)

Browse Journals / Lookup Meetings

Browse by Journal and Year


Lookup Conference Papers

Close Browse Journals / Lookup Meetings

Article Tools



A monolithic coupling scheme for mid-infrared quantum cascade laser arrays is investigated with respect to brightness enhancement. The tree-shaped resonator enables parallel coupling of six laser elements into a single element by means of several Y-junctions. Phase-locking is observed on the basis of far field analysis, and leads to in-phase emission on both sides of the device. The experimental results match calculated far field profiles and demonstrate a high level of modal control when driven far above threshold. Whereas optical power measurements confirm negligible coupling losses, the slope efficiency is below the theoretically expected value, which is attributed to modal competition. Additional evaluation of near fields and spectral characteristics provides background on the modal dynamics of the sophisticated cavity and reveals limitations to coherent beam combining. The findings pave the way to improved coupling efficiency and brightness scaling of a single facet emitting compact quantum cascade laser array.

© 2009 Optical Society of America

OCIS Codes
(140.3070) Lasers and laser optics : Infrared and far-infrared lasers
(140.3290) Lasers and laser optics : Laser arrays
(140.3410) Lasers and laser optics : Laser resonators
(140.3295) Lasers and laser optics : Laser beam characterization
(140.5965) Lasers and laser optics : Semiconductor lasers, quantum cascade

ToC Category:
Lasers and Laser Optics

Original Manuscript: November 12, 2008
Revised Manuscript: December 15, 2008
Manuscript Accepted: December 15, 2008
Published: January 7, 2009

Leonard K. Hoffmann, Matthias Klinkmüller, Elvis Mujagić, Mykhaylo P. Semtsiv, Werner Schrenk, William T. Masselink, and Gottfried Strasser, "Tree array quantum cascade laser," Opt. Express 17, 649-657 (2009)

Sort:  Author  |  Year  |  Journal  |  Reset  


  1. J. Devenson, O. Cathabard, R. Teissier, and A. N. Baranov, "InAs/AlSb quantum cascade lasers emitting at 2.75-2.97 μm," Appl. Phys. Lett. 91, 251102 (2007). [CrossRef]
  2. R. Colombelli, F. Capasso, C. Gmachl, A. L. Hutchinson, D. L. Sivco, A. Tredicucci, M. C. Wanke, A. M. Sergent, and A. Y. Cho, "Far-infrared surface-plasmon quantum-cascade lasers at 21.5 μm and 24 μm wavelengths," Appl. Phys. Lett. 78, 2620-2622 (2001). [CrossRef]
  3. Y. Bai, S. Slivken, S. R. Darvish, and M. Razeghi, "Room temperature continuous wave operation of quantum cascade lasers with 12.5% wall plug efficiency," Appl. Phys. Lett. 93, 021103 (2008). [CrossRef]
  4. A. Lyakh, C. Pflügl, L. Diehl, Q. J. Wang, F. Capasso, X. J. Wang, J. Y. Fan, T. Tanbun-Ek, R. Maulini, A. Tsekoun, R. Go, and C. K. N. Patel, "1.6 W high wall plug efficiency, continuous-wave room temperature quantum cascade laser emitting at 4.6 μm," Appl. Phys. Lett. 92, 111110 (2008). [CrossRef]
  5. A. Wittmann, T. Gresch, E. Gini, L. Hvozdara, N. Hoyler, M. Giovannini, and J. Faist, "High-performance bound-to-continuum quantum-cascade lasers for broad-gain applications," IEEE J. Quantum Electron. 44, 36-40 (2008). [CrossRef]
  6. L. Diehl, D. Bour, S. Corzine, J. Zhu, G. Höfler, M. Lončar, M. Troccoli, and F. Capasso, "High-power quantum cascade lasers grown by low-pressure metal organic vapor-phase epitaxy operating in continuous wave above 400K," Appl. Phys. Lett. 88, 201115 (2006). [CrossRef]
  7. V. Spagnolo, A. Lops, G. Scamarcio,M. S. Vitiello, and C. Di Franco, "Improved thermal management of mid-IR quantum cascade lasers," J. Appl. Phys. 103, 043103 (2008). [CrossRef]
  8. E. Mujagič, L. K. Hoffmann, S. Schartner, M. Nobile, W. Schrenk, M. P. Semtsiv, M. Wienold, W. T. Masselink, and G. Strasser, "Low divergence single-mode surface emitting quantum cascade ring lasers," Appl. Phys. Lett. 93, 161101 (2008). [CrossRef]
  9. M. Carras, M. Garcia, X. Marcadet, O. Parillaud, A. De Rossi, and S. Bansropun, "Top grating index-coupled distributed feedback quantum cascade lasers," Appl. Phys. Lett. 93, 011109 (2008). [CrossRef]
  10. Y. Bai, S. R. Darvish, S. Slivken, P. Sung, J. Nguyen, A. Evans,W. Zhang, andM. Razeghi, "Electrically pumped photonic crystal distributed feedback quantum cascade lasers," Appl. Phys. Lett. 91, 141123 (2007). [CrossRef]
  11. G. Wysocki, R. Lewicki, R. F. Curl, F. K. Tittel, L. Diehl, F. Capasso,M. Troccoli, G. Hofler, D. Bour, S. Corzine, R. Maulini, M. Giovannini, and J. Faist, "Widely tunable mode-hop free external cavity quantum cascade lasers for high resolution spectroscopy and chemical sensing," Appl. Phys. B 92, 305-311 (2008). [CrossRef]
  12. W. W. Bewley, J. R. Lindle, C. S. Kim, I. Vurgaftman, J. R. Meyer, A. J. Evans, J. S. Yu, S. Slivken, and M. Razeghi, "Beam steering in high-power cw quantum-cascade lasers," IEEE J. Quantum Electron. 41, 833-841 (2005). [CrossRef]
  13. M. Wienold, M. P. Semtsiv, I. Bayrakli, W. T. Masselink, M. Ziegler, K. Kennedy, and R. Hogg, "Optical and thermal characteristics of narrow-ridge quantum-cascade lasers," J. Appl. Phys. 103, 083113 (2008). [CrossRef]
  14. A. Lytkine, B. Lau, A. Lim, W. Jäger, and J. Tulip, "Range-resolved gas concentration measurements using tunable semiconductor lasers," Appl. Phys. B 90, 339-343 (2008). [CrossRef]
  15. M. Taslakov, V. Simeonov, M. Froidevaux, and H. van den Bergh, "Open-path ozone detection by quantumcascade laser," Appl. Phys. B 82, 501-506 (2006). [CrossRef]
  16. R. Martini and E. A. Whittaker, "Quantum cascade laser-based free space optical communications," J. Opt. Fiber. Commun. Rep. 2, 279-292 (2005). [CrossRef]
  17. M. C. Phillips and N. Hô, "Infrared hyperspectral imaging using a broadly tunable external cavity quantum cascade laser and microbolometer focal plane array," Opt. Express 16, 1836-1845 (2008). [CrossRef] [PubMed]
  18. B. Guo, Y. Wang, C. Peng, H. L. Zhang, G. P. Luo, H. Q. Le, C. Gmachl, D. L. Sivco, M. L. Peabody, and A. Y. Cho, "Laser-based mid-infrared reflectance imaging of biological tissues," Opt. Express 12, 208-219 (2004). [CrossRef] [PubMed]
  19. T. Y. Fan, "Laser beam combining for high-power, high-radiance sources," IEEE J. Sel. Top. Quantum Electron. 11, 567-577 (2005). [CrossRef]
  20. D. Botez, "Monolithic phase-locked semiconductor laser arrays," in Diode Laser Arrays, D. Botez and D. R. Scrifres, eds. (Cambridge University Press, 1994), pp. 1-71.
  21. D. Botez, "High-power monolithic phase-locked arrays of antiguided semiconductor diode lasers," IEE Proc. 139, 14-23 (1992).
  22. F. Causa and D. Masanotti, "Observation and analysis of phase-locking in parabolic bow-tie laser arrays," IEEE J. Quantum Electron. 42, 1016-1022 (2006). [CrossRef]
  23. V. C. Elarde, K. E. Tobin, R. K. Price, V. B. Verma, and J. J. Coleman, "Curved waveguide array diode lasers for high-brightness applications," IEEE Photon. Technol. Lett. 20, 1085-1087 (2008). [CrossRef]
  24. J. E. A. Whiteaway, D. J. Moule, and S. J. Clements, "Tree array lasers," Electron. Lett. 25, 779-781 (1989). [CrossRef]
  25. L. K. Hoffmann, C. A. Hurni, S. Schartner, M. Austerer, E. Mujagić, M. Nobile, A. Benz, W. Schrenk, A. M. Andrews, P. Klang, and G. Strasser, "Coherence in Y-coupled quantum cascade lasers," Appl. Phys. Lett. 91, 161106 (2007). [CrossRef]
  26. L. K. Hoffmann, C. A. Hurni, S. Schartner, E. Mujagić, A. M. Andrews, P. Klang, W. Schrenk, M. P. Semtsiv, W. T. Masselink, and G. Strasser, "Wavelength dependent phase locking in quantum cascade laser Y-junctions," Appl. Phys. Lett. 92, 061110 (2008). [CrossRef]
  27. L. K. Hoffmann, M. Austerer, E. Mujagić, A. M. Andrews, P. Klang, W. Schrenk, and G. Strasser, "Monolithic Mach-Zehnder-type quantum cascade laser," J. Appl. Phys. 104, 063110 (2008). [CrossRef]
  28. P. W. Smith, "Mode selection in lasers," Proc. IEEE 60, 422-440 (1972). [CrossRef]
  29. M. Beck, D. Hofstetter, T. Aellen, J. Faist, U. Oesterle, M. Ilegems, E. Gini, and H. Melchior, "Continuous wave operation of a mid-infrared semiconductor laser at room temperatur," Science 295, 301-305 (2002). [CrossRef] [PubMed]
  30. R. P. Green, L. R. Wilson, E. A. Zibik, D. G. Revin, J. W. Cockburn, C. Pflügl, W. Schrenk, G. Strasser, A. B. Krysa, J. S. Roberts, C. M. Tey, and A. G. Cullis, "High-performance distributed feedback quantum cascade lasers grown by metalorganic vapor phase epitaxy," Appl. Phys. Lett. 85, 5529-5531 (2004). [CrossRef]
  31. Z. Weissman and A. Hardy, "Mode-dependent radiation loss in Y-junctions and directional couplers," IEEE J. Quantum Electron. 25, 1200-1208 (1989). [CrossRef]

Cited By

Alert me when this paper is cited

OSA is able to provide readers links to articles that cite this paper by participating in CrossRef's Cited-By Linking service. CrossRef includes content from more than 3000 publishers and societies. In addition to listing OSA journal articles that cite this paper, citing articles from other participating publishers will also be listed.


Fig. 1. Fig. 2. Fig. 3.
Fig. 4.

« Previous Article  |  Next Article »

OSA is a member of CrossRef.

CrossCheck Deposited