Investigating the Modal Dependencies of Beam Quality - Via Spectrally-resolved Imaging of the Mode Structure in Diode Lasers

Stephen M. Misak, James A. Beil, Rebecca B. Swertfeger, Paul O. Leisher

Abstract

Laser beam quality is an important factor for free-space communication and other high power applications. To achieve the power requirements for such applications, there is a trade-off with the M2 Beam Quality factor. While direct diode lasers offer higher efficiency in a smaller footprint compared to solid-state and fiber laser systems, beam quality is poor due to multi-mode operation. M2 measurements compliant with ISO 11146 standards require numerous measurements, especially for multimode lasers. It is possible to use faster, modal decomposition methods for measuring M2 by employing a spectrometer to spatially separate the modes of a laser. This work presents a custom Echelle Grating Spectrometer for spatially separating laser modes. This tool provides the basis for an alternative method of M2 measurements via Modal Power Distribution analysis.

References

  1. Crist, J. and Nelson, C. (2012) 'Predicting laser beam characteristics', Laser Technik Journal, Vol. 9, No. 1, Available from: doi.org/ 10.1002/latj.201290006.
  2. Crump, P. et al. (2012) 'Experimental and theoretical analysis of the dominant lateral waveguiding mechanism in 975 nm high power broad area diode lasers', Semiconductor Science and Technology, Vol. 27, No. 4, Available from: doi.org/10.1088/0268- 1242/27/4/045001.
  3. International Organization for Standardization 2005, Lasers and laser-related equipment - Test methods for laser beam widths, divergence angles and beam propagation ratios - Part 1: Stigmatic and simple astigmatic beams, ISO 11146-1:2005, International Organization for Standardization, Geneva.
  4. Kanskar, M. et al. (2013) 'High Reliability of High Power and High Brightness Diode Lasers', nLight Corporation, Available from: http://www.nlight.net/ news/technical-papers.
  5. Kelemen, M. T. et al. (2009) 'High-Power High-Brightness Lasers', m2k-laser GmbH, Available from: http:// www.optosolutions.com/doc/TaperedLaser_intro_070 209.pdf (Accessed 08 August 2016).
  6. Kelemen, M. T. et al. (2004) 'Astigmatism and Beam Quality of High-brightness Tapered Laser Diodes', Semiconductor Lasers and Laser Dynamics, Strasbourg, France, SPIE, Vol. 5452, No. 233. Available from: doi.org/10.1117/12.545221.
  7. Misak, S. M. et al. (2015) 'Spectrally Resolved Imaging of the transverse modes in multimode VCSELs', VerticalCavity Surface Emitting Lasers, San Francisco, CA, SPIE, Vol. 9381, No. 93810L. Available from: doi.org/10.1117/12.2076629.
  8. Schmidt, O. A. et al. (2011) 'Real-time determination of laser beam quality by modal decomposition', Optics Express, Vol. 19, No. 7, pp. 6741-6748. Available from: doi.org/10.1364/OE.19.006741.
  9. Siegman, A. E. (1993) 'Defining, measuring, and optimizing laser beam quality,78 Laser Resonators and Coherent Optics, Los Angeles, CA, SPIE, Vol. 1868, No 2. Available from: doi.org/10.1117/12.150601.
  10. Siegman, A. E. and Townsend S. (1993) 'Output beam propagation and beam quality from a multimode stabecavity laser', IEEE Journal of Quantum Electronics, Vol. 29, No. 4, pp. 1212-1217. Available from: doi.org/10.1109/3.214507.
  11. Stelmakh, N. (2009) 'External-to-cavity lateral-mode harnessing devices for high-brightness broad-area laser diodes: concept, realizations, and perspectives' Novel In-Place Semiconductor Lasers, San Jose, CA, SPIE, Vol. 7230, No. 72301B. Available from: doi.org/10.1117/12.808681.
  12. Sun, H. (1997) 'Measurement of laser diode astigmatism', Opt. Eng., Vol. 36, No. 4, pp. 1082-1087 Available from: doi.org/10.1117/1.601147.
Download


Paper Citation


in Harvard Style

Misak S., Beil J., Swertfeger R. and Leisher P. (2017). Investigating the Modal Dependencies of Beam Quality - Via Spectrally-resolved Imaging of the Mode Structure in Diode Lasers . In Proceedings of the 5th International Conference on Photonics, Optics and Laser Technology - Volume 1: PHOTOPTICS, ISBN 978-989-758-223-3, pages 245-251. DOI: 10.5220/0006152702450251


in Bibtex Style

@conference{photoptics17,
author={Stephen M. Misak and James A. Beil and Rebecca B. Swertfeger and Paul O. Leisher},
title={Investigating the Modal Dependencies of Beam Quality - Via Spectrally-resolved Imaging of the Mode Structure in Diode Lasers},
booktitle={Proceedings of the 5th International Conference on Photonics, Optics and Laser Technology - Volume 1: PHOTOPTICS,},
year={2017},
pages={245-251},
publisher={SciTePress},
organization={INSTICC},
doi={10.5220/0006152702450251},
isbn={978-989-758-223-3},
}


in EndNote Style

TY - CONF
JO - Proceedings of the 5th International Conference on Photonics, Optics and Laser Technology - Volume 1: PHOTOPTICS,
TI - Investigating the Modal Dependencies of Beam Quality - Via Spectrally-resolved Imaging of the Mode Structure in Diode Lasers
SN - 978-989-758-223-3
AU - Misak S.
AU - Beil J.
AU - Swertfeger R.
AU - Leisher P.
PY - 2017
SP - 245
EP - 251
DO - 10.5220/0006152702450251