High power fiber lasers are proposed to be a better candidate than conventional solid-state lasers for industries such as precision engineering since they are more compact and easier to operate. However, the beam quality generally degrades when one scales up the output power of the fiber laser. One can improve the output beam quality by altering the phase of the laser beam at the exit surface, and a promising method to do so is by integrating specially designed nano-structures at the laser facets. In fact, this method was recently demonstrated – by integrating gold concentric ring grating structures to the facet of a quantum cascade laser, one observes significant improvement in the beam quality. Nevertheless, to improve the beam quality of high power fiber lasers using the method mentioned above, the material of the nano-structures must be able to withstand high laser fluence in the range of J/cm². In this work, we investigated the laser-induced damage threshold (LIDT) values of a suitable material for high intensity fiber laser applications. Consequently, we demonstrated that the shortlisted material and the fabricated nanostructures can withstand laser fluence exceeding 1.0 J/cm².

Date Published: 27 August 2014
PDF: 4 pages
Proc. SPIE 9172, Nanostructured Thin Films VII, 917207 (27 August 2014); doi: 10.1117/12.2061260

Published in SPIE Proceedings Vol. 9172:
Nanostructured Thin Films VII
Akhlesh Lakhtakia; Tom G. Mackay; Motofumi Suzuki, Editor(s)