Journal of Materials Science

, Volume 54, Issue 9, pp 6772–6785 | Cite as

Strengthening of very large crystalline and polycrystalline Nd:YAG rods for high-power laser applications

  • Revital FeldmanEmail author
  • Steven Jackel
  • Inon Moshe
  • Avi Meir
  • Eyal Lebiush
  • Zvi Horowitz
  • Yaakov Lumer
  • Yehoshua Shimony


A multistep thermochemical etching procedure was applied to very large Nd3+:YAG rods to increase their fracture strength. The strengthening procedure combined selection of high-quality material, fine centerless grinding, thermochemical etching, and (after completion of the lapping, polishing and AR coating) an additional hot thermochemical etching, with rod ends protected with poly-tetra-fluoro-ethylene (Teflon) caps. The final cleaning step, not previously reported, is essential in removing fracture causing contaminations on the rod surface. A unique thermal load-to-fracture technique was applied on test rods to measure their fracture strength. The rods were thermally loaded up to fracture by means of optical pumping in a specially designed laser pump chamber. The results thus obtained were analyzed by Weibull distribution statistics appropriate to these tests. The strengthened laser rods of this study sustained a maximum pump power density of \( I_{{\ell_{\hbox{max} } }} \) = 500 W cm−1. This value is higher by a factor of four over untreated rods and also higher than any previously published data for such large rods. High-power diode-pumped laser heads were operated with the strengthened crystalline and polycrystalline Nd:YAG rods, yielded output power of ~ 3 kW, when pumped with 7 kW. Such performance was routinely achieved without any instance of rod fracture. Reliability of the strengthening procedure was further demonstrated by the failure-free operation of an azimuthally polarized high-power master-oscillator power-amplifier system (composed of oscillator, preamplifier, and six power amplifiers), emitting an output power in excess of 10 kW.


Compliance with ethical standards

Conflict of interest

The work presented in this publication has been carried out for few years in Soreq Nuclear Research Center, Yavne, Israel, as an Infrastructure Development Program for solid-state lasers without any external funding. All authors of the present publications declare that they have no conflict of interest with respect to this publication.


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Authors and Affiliations

  1. 1.Applied Physics DivisionSoreq NRCYavneIsrael

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