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Identification of optical parameters for determination of radiance

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Abstract

The ‘brightness’ of coherent beams such as lasers is known as ‘radiance’ in radiometric terms. It is a concept which is rarely taken into account in laser material processing, laser system design, and for the characterization of laser beams. The typical beam parameters such as: laser power; spot size; intensity; wavelength; beam divergence and the beam propagation factor - M2, combined together are factors which determine the ‘radiance’ of lasers or energy beams in general. The concept of ‘brightness’ (‘radiance’ in particular), and how the laser beam parameters contribute to affect ‘radiance’, has not so far been reported in previous literature. Thus, we have investigated the theoretical ‘radiance’ for each parameter in relation to one another. In addition, a rather suitable empirical equation to determine the ‘radiance’ was also introduced herein, since, the existing equation for calculating ‘brightness’ do not employ the total power intensity of the beam. Based on this, we consider ‘power density’ rather than the ‘output power’ for determining radiance of a selected 1.064 μm wavelength Nd:YAG laser for a set laser processing parameter window. The analytical investigation firstly concluded that the inclusion of ‘power density’ into the equation takes in account of ‘spot size’ and ‘laser power’ to cover all laser beam parameters. Secondly, the results have shown wavelength to be the most contributory parameter to influence the radiance value followed by power density, M2, laser power and lastly the spot size of the laser beam. This was for a set-condition applied, but is generically applicable to different conditions and parameters, whereby, the same tendency would occur. This novel concept of brightness (radiance), of light sources such as a laser beam is not just useful for process control during laser material processing, but could prove to be a very effective concept for laser beam characterization, and in laser system design for enhancing the ‘brightness’ or ‘radiance’ of lasers. Also not just lasers but, the concept could be applicable for other energy beams in general.

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References

  1. R. Paschotta, Physics and Technology. Encyclopedia of lase (Wiley – VCH, Berlin, 2008)

    Google Scholar 

  2. J. Wilson, F.B.J. Hawkes, Lasers Principles and Applications (Prentice Hall International Ltd, United Kingdom, 1987)

    Google Scholar 

  3. F.J. Ready, Industrial Applications of lasers (Academic Press Inc, New York, 1978)

    Google Scholar 

  4. J. Robieux, High power laser interactions (Lavoisier Publishing, Paris, 2000)

    Google Scholar 

  5. P.W. Milonni, J.H. Eberly, Lasers (Wiley, Canada, 1998)

    Google Scholar 

  6. J. Almeida, D. Liang, E. Guillot, Improvement in solar-pumped Nd:YAG laser beam brightness. Opt. Laser Technol. 44, 2115–2119 (2012)

    Article  ADS  Google Scholar 

  7. British Standards. Laser and laser-related equipment -Test methods for laser beam parameters- Beam width, divergence angle and beam. BS EN ISO 11146. 2000

  8. British Standards. Lasers and laser-related equipment - Test methods for laser beam widths, divergence angles and beam propagation ratios - Part 1: Stigmatic and simple astigmatic beams. BS EN ISO 11146–1. 2005.

  9. British Standards. Lasers and laser-related equipment -Test methods for laser beam widths, divergence angles and beam propagation ratios - Part 2: General astigmatic beams. BS EN ISO 11146–2. 2005.

  10. P.P. Shukla, J. Lawrence, A. Paul, Influence of laser beam brightness during laser surface treatment of ZrO2 engineering ceramics. Laser Eng. 22(3–4), 151–173 (2011)

    Google Scholar 

  11. Shukla, P., 2011, Viability and Characterization of the Laser Surface Treatment of Engineering Ceramics, A doctoral thesis: Loughborough University.

  12. P.P. Shukla, J. Lawrence, The influence of brightness during laser surface treatment of Si3N4 engineering ceramics. Opt. Lasers Eng. 50, 1746–1751 (2012)

    Article  Google Scholar 

  13. Brown R. T., and Frye, R. W., 1996, High-brightness laser cutting & drilling of aerospace materials. Proceedings of ICALEO-1996, Section C, 77–75.

  14. J.R. Val Comesaña, F. Lusquiños, M. Boutinguiza, A. Riveiro, F. Quintero, J. Pou, Laser cladding of Co-based superalloy coatings: comparative study between Nd:YAG laser and fibre laser. J. Surf. Coat. Technol. 204, 1957–1961 (2010)

    Article  Google Scholar 

  15. Hanna, D.C., 1970, Increase laser brightness by transverse mode Section −1, Optics and Laser Technology, 122–125.

  16. Hanna, D.C., 1970, Increasing laser brightness by transverse mode Section - 2, Optics and Laser Technology, 175–178.

  17. Author?? Brightness or radiance of laser beams, pp 21. Publisher? City?

  18. Encyclopaedia of laser physics and Technology, www.rp-photonics.com/brightness.html.

  19. J.C. Ion, Laser processing of engineering materials (Elsevier Butterworth Heinemann, Oxford, U.K., 2005)

    Google Scholar 

  20. V. Shepelev, About transforming of radiation brightness in optical process. Amer. Assoc. Phys. Technol. 78(2), 158–159 (2009)

    Google Scholar 

  21. W. Koechner, Solid-state laser engineering. 5th revised and updated edition Berlin (Springer, Germany, 1999)

    Book  Google Scholar 

Download references

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Authors and Affiliations

  1. Laser Engineering and Manufacturing Research Group, Faculty of Science and Engineering, University of Chester, Parkgate Road, Chester, CH1 4BJ, United Kingdom

    Pratik P. Shukla & Jonathan Lawrence

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  1. Pratik P. Shukla
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  2. Jonathan Lawrence
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Correspondence to Pratik P. Shukla.

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Shukla, P.P., Lawrence, J. Identification of optical parameters for determination of radiance. J Opt 44, 12–19 (2015). https://doi.org/10.1007/s12596-014-0219-4

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  • DOI: https://doi.org/10.1007/s12596-014-0219-4

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