Modification of multilayer mirror top-layer design for increased laser damage resistance

Laser Damage Resistant Ta2O5/HfO2/SiO2 Multilayer Mirrors by Ion Beam Sputtering

“…Its laser damage resistance at nanosecond pulse durations is, however, lower than similar multilayers that employ HfO 2 or Y 2 O 3 as the high index material We have already demonstrated increases in the laser damage threshold fluence of a Ta 2 O 5 /SiO 2 high reflection multilayer through replacement of Ta 2 O 5 with HfO 2 in the top three bilayers when tested using 0.35 ns pulses at λ = 1 μm [3]. We have also demonstrated the role of SiO 2 capping layers that reduce the electric field intensity in the structure to improve the laser induced damage resistance from laser pulses of 0.19 ns and 4 ns duration [4]. In this work, the effect of combining design techniques to increase the damage resistance of Ta 2 O 5 /SiO 2 high reflectors is explored and compared with HfO 2 /SiO 2 and Ta 2 O 5 /SiO 2 quarter-wave designs.…”

“…We have also demonstrated the role of SiO 2 capping layers that reduce the electric field intensity in the structure to improve the laser induced damage resistance from laser pulses of 0.19 ns and 4 ns duration [4]. In this work, the effect of combining design techniques to increase the damage resistance of Ta 2 O 5 /SiO 2 high reflectors is explored and compared with HfO 2 /SiO 2 and Ta 2 O 5 /SiO 2 quarter-wave designs.…”

Bandgap energy of quantizing nanolaminates and its relation to the laser-induced damage threshold in the ultraviolet

“…Different approaches focused on the thin film design or used materials were previously tested to increase the LIDT in the ultra-short pulse regime. Designs with optimized electric field intensity (EFI) distributions [2,3] are one example, where changes in the layer thickness of the top layers shift the maximum EFI into a low-index layer, which exhibits a higher intrinsic LIDT. Ternary composites [3,4,5], produced by mixing the high-index with a suitable low-index material, were also tested.…”

Ultrafast laser interaction with transparent multi-layer SiO2/Si3N4 films

“…Csajbok et al 18,19 reported that the intensity of the laser's electric field along the multilayer stack is periodically modulated along the propagation axis, according to the stack geometry and composition, presenting intensity minima and maxima. As a result, in standard designs of distributed Bragg reflectors (DBRs), the multilayers weakest points with respect to the damage threshold reside at the interfaces with the high-index materials, so that the materials resistance to the laser can be improved by modifying the layers design, shifting the electric field's intensity peaks towards the lower-index layers [20][21][22][23][24] . The intensity has also been found to be enhanced locally by pits, scratches and more generally defects, resulting in higher damages of the multilayers in these regions [25][26][27][28] .…”